Audiology - Anatomy And Physiology Of The Ear

1. Eustachian tube blockages are common, especially in children, and often lead to middle ear problems.

True

False

Eustachian tube blockages are common, especially in children, and often lead to middle ear problems. This means that the statement is true.

Explanation

Eustachian tube blockages are common, especially in children, and often lead to middle ear problems. This means that the statement is true.

2. The auditory ossicles (incus, malleus, and stapes) can be found in which part of the ear?

Middle ear

Outer ear

Inner ear

The auditory ossicles, including the incus, malleus, and stapes, are located in the middle ear. The middle ear is the space between the eardrum and the inner ear. These tiny bones transmit sound vibrations from the eardrum to the inner ear, where they are converted into electrical signals that can be interpreted by the brain.

Explanation

The auditory ossicles, including the incus, malleus, and stapes, are located in the middle ear. The middle ear is the space between the eardrum and the inner ear. These tiny bones transmit sound vibrations from the eardrum to the inner ear, where they are converted into electrical signals that can be interpreted by the brain.

3. The External Auditory Meatus is lined with skin and leads from the bottom of the concha of the pinna to the tympanic membrane.

True

False

The external auditory meatus, also known as the ear canal, is indeed lined with skin. It is a tube-like structure that starts from the bottom of the concha of the pinna (the visible part of the ear) and extends to the tympanic membrane (eardrum). This lining of skin helps protect the ear canal and also plays a role in the production of earwax. Therefore, the statement provided is true.

Explanation

The external auditory meatus, also known as the ear canal, is indeed lined with skin. It is a tube-like structure that starts from the bottom of the concha of the pinna (the visible part of the ear) and extends to the tympanic membrane (eardrum). This lining of skin helps protect the ear canal and also plays a role in the production of earwax. Therefore, the statement provided is true.

4. What is the main function of the Eustachian tube?

Aerate the middle ear so that pressure in the middle ear cavity remains the same as the atmospheric pressure

Amplify sounds through to the fluid-filled cochlea

Help maintain balance and proprioception

Increase the pressure inside the inner ear cavity

This allows the tympanic membrane to vibrate with the sound waves

Explanation

This allows the tympanic membrane to vibrate with the sound waves

5. The auditory ossicles (incus, malleus, and stapes) form a chain which connect the tympanic membrane with what?

Oval window

Bony labyrinth

Eustachian tube

Nasopharynx

The auditory ossicles (incus, malleus, and stapes) form a chain that connects the tympanic membrane (eardrum) to the oval window. The oval window is a membrane-covered opening that separates the middle ear from the inner ear. When sound waves enter the ear and cause the tympanic membrane to vibrate, these vibrations are transmitted through the auditory ossicles and ultimately to the oval window. The oval window then transfers these vibrations to the fluid-filled cochlea in the inner ear, where they are converted into electrical signals that can be interpreted by the brain as sound.

Explanation

The auditory ossicles (incus, malleus, and stapes) form a chain that connects the tympanic membrane (eardrum) to the oval window. The oval window is a membrane-covered opening that separates the middle ear from the inner ear. When sound waves enter the ear and cause the tympanic membrane to vibrate, these vibrations are transmitted through the auditory ossicles and ultimately to the oval window. The oval window then transfers these vibrations to the fluid-filled cochlea in the inner ear, where they are converted into electrical signals that can be interpreted by the brain as sound.

6. At birth, the Eustachian tube is almost completely horizontal.

True

False

At birth, the Eustachian tube is almost completely horizontal. This is because the Eustachian tube, which connects the middle ear to the back of the throat, is not fully developed in newborns. As a result, it is positioned more horizontally than in adults. This horizontal orientation can make it more difficult for fluid to drain from the middle ear, which can contribute to ear infections in infants and young children. As the child grows, the Eustachian tube gradually becomes more vertical, allowing for better drainage and reducing the risk of ear infections.

Explanation

At birth, the Eustachian tube is almost completely horizontal. This is because the Eustachian tube, which connects the middle ear to the back of the throat, is not fully developed in newborns. As a result, it is positioned more horizontally than in adults. This horizontal orientation can make it more difficult for fluid to drain from the middle ear, which can contribute to ear infections in infants and young children. As the child grows, the Eustachian tube gradually becomes more vertical, allowing for better drainage and reducing the risk of ear infections.

7. Perilymph and endolymph occupy separate compartments and hence do not mix.

True

False

Perilymph and endolymph are two different fluids that exist in the inner ear. They are separated by membranes and occupy separate compartments, which prevents them from mixing together. This separation is important for maintaining the proper functioning of the inner ear and its sensory functions. Therefore, the statement that perilymph and endolymph do not mix is true.

Explanation

Perilymph and endolymph are two different fluids that exist in the inner ear. They are separated by membranes and occupy separate compartments, which prevents them from mixing together. This separation is important for maintaining the proper functioning of the inner ear and its sensory functions. Therefore, the statement that perilymph and endolymph do not mix is true.

8. The speed at which sound travels depends on the elasticity of the medium through which it is travelling.

True

False

Sound travels faster through more elastic mediums

Explanation

Sound travels faster through more elastic mediums

9. Match the description of Eustachian tubes to adults or children.

Children

Adult

These differences, coupled with an immature immune system, make middle ear infections more common in children

Explanation

These differences, coupled with an immature immune system, make middle ear infections more common in children

Submit

10. The human ear can detect what range of frequencies?

20-20,000 Hz

20-2,000 Hz

20-200,000 Hz

20-200 Hz

The human ear can detect a range of frequencies from 20 to 20,000 Hz. This range is commonly referred to as the audible frequency range. Frequencies below 20 Hz are considered infrasound and frequencies above 20,000 Hz are considered ultrasound, which are typically not audible to the human ear. The range of 20-20,000 Hz encompasses the frequencies of most sounds that we encounter in our daily lives, including speech, music, and environmental sounds.

Explanation

The human ear can detect a range of frequencies from 20 to 20,000 Hz. This range is commonly referred to as the audible frequency range. Frequencies below 20 Hz are considered infrasound and frequencies above 20,000 Hz are considered ultrasound, which are typically not audible to the human ear. The range of 20-20,000 Hz encompasses the frequencies of most sounds that we encounter in our daily lives, including speech, music, and environmental sounds.

11. The middle ear is an air-filled chamber which sits between the ear canal and the inner ear. How is it connected to the nasopharynx?

Via the Eustachian tube

Via the External Auditory Meatus

Via the fluid-filled cochlea

Via the bony labyrinth

The middle ear is connected to the nasopharynx via the Eustachian tube. This tube acts as a pathway that allows air to flow between the middle ear and the back of the throat. It helps to equalize the pressure on both sides of the eardrum, ensuring that the eardrum can vibrate properly and allowing for normal hearing.

Explanation

The middle ear is connected to the nasopharynx via the Eustachian tube. This tube acts as a pathway that allows air to flow between the middle ear and the back of the throat. It helps to equalize the pressure on both sides of the eardrum, ensuring that the eardrum can vibrate properly and allowing for normal hearing.

12. The inner ear comprises of the osseous (bony) labyrinth and the membranous labyrinth. Match the labyrinths to their descriptions

Osseous labyrinth

Membranous labyrinth

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13. As this OHC expansion and contraction only occurs at the specific region of the cochlea tuned to the incoming frequency, it ____________ the cochlea's frequency selectivity (cochlear tuning).

Increases

Decreases

It also AMPLIFIES quieter sounds, thus LOWERING the hearing threshold

Explanation

It also AMPLIFIES quieter sounds, thus LOWERING the hearing threshold

14. The organ of Corti is the sensitive element in the inner ear and can be thought of as the "body's microphone". Where is it situated?

On the basilar membrane

Behind the oval window

Beside the cochlea

At the top of the Eustachian tube

The organ of Corti is situated on the basilar membrane. It is a structure in the inner ear that contains hair cells, which are responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. The basilar membrane is a thin, flexible membrane that runs along the length of the cochlea, which is the spiral-shaped structure of the inner ear. The organ of Corti sits on top of the basilar membrane and is essential for hearing.

Explanation

The organ of Corti is situated on the basilar membrane. It is a structure in the inner ear that contains hair cells, which are responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. The basilar membrane is a thin, flexible membrane that runs along the length of the cochlea, which is the spiral-shaped structure of the inner ear. The organ of Corti sits on top of the basilar membrane and is essential for hearing.

15. These otoacoustic emissions arise from the energy produced by __________________ action under control of the efferent input to the cochlea.

Outer hair cell

Inner hair cell

Testing for the presence of OAEs is the basis of neonatal hearing screening.

Explanation

Testing for the presence of OAEs is the basis of neonatal hearing screening.

16. The nerve fibres carrying sound signals lead to different parts of the auditory cortex depending on the frequencies they carry.

True

False

Different frequencies of sound are processed in different regions of the auditory cortex. This is known as tonotopy, which means that neighboring neurons in the auditory cortex respond to different frequencies. This organization allows the brain to analyze and interpret different aspects of sound, such as pitch and timbre. Therefore, it is true that nerve fibers carrying sound signals lead to different parts of the auditory cortex depending on the frequencies they carry.

Explanation

Different frequencies of sound are processed in different regions of the auditory cortex. This is known as tonotopy, which means that neighboring neurons in the auditory cortex respond to different frequencies. This organization allows the brain to analyze and interpret different aspects of sound, such as pitch and timbre. Therefore, it is true that nerve fibers carrying sound signals lead to different parts of the auditory cortex depending on the frequencies they carry.

17. The travelling wave peaks at the part of the basilar membrane which is tuned to the stimulus frequency and then dies away.

True

False

The part near the base moves first, followed by successively more apical segments.

Explanation

The part near the base moves first, followed by successively more apical segments.

18. Different regions of the basilar membrane respond maximally to different sound frequencies. Match the areas of the basilar membrane to the sounds they respond to.

Base of the basilar membrane (narrow and stiff)

Apex of the basilar membrane (wide and slack)

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19. How does the tympanic membrane receive the incoming sound?

Vibrates back and forth with incoming compressions and rarefactions of the sound wave

Vibrates with the incoming compressions of the sound wave

Tympanic membrane pushes inwards alongside the sound waves

Tympanic membrane is forced outwards with the vibrations of the sound wave

The correct answer is "Vibrates back and forth with incoming compressions and rarefactions of the sound wave." The tympanic membrane, also known as the eardrum, receives sound waves and vibrates in response to the incoming compressions and rarefactions of the sound wave. This vibration is then transmitted to the middle ear, where it is further amplified and transmitted to the inner ear for processing and interpretation.

Explanation

The correct answer is "Vibrates back and forth with incoming compressions and rarefactions of the sound wave." The tympanic membrane, also known as the eardrum, receives sound waves and vibrates in response to the incoming compressions and rarefactions of the sound wave. This vibration is then transmitted to the middle ear, where it is further amplified and transmitted to the inner ear for processing and interpretation.

20. One Hz is equal to...

One complete cycle (one compression and one rarefaction)

One compression

One rarefaction

None of the above

The correct answer is "One complete cycle (one compression and one rarefaction)." This is because one Hz (Hertz) represents one complete oscillation or vibration per second. In the context of sound waves, one complete cycle includes both a compression (where the particles are closer together) and a rarefaction (where the particles are spread apart). Therefore, one Hz corresponds to one complete cycle of a sound wave, which includes both a compression and a rarefaction.

Explanation

The correct answer is "One complete cycle (one compression and one rarefaction)." This is because one Hz (Hertz) represents one complete oscillation or vibration per second. In the context of sound waves, one complete cycle includes both a compression (where the particles are closer together) and a rarefaction (where the particles are spread apart). Therefore, one Hz corresponds to one complete cycle of a sound wave, which includes both a compression and a rarefaction.

21. The frequency of the sound wave determines the sound's...

Pitch

Loudness

Length

Clarity

The frequency of a sound wave refers to the number of cycles or vibrations the wave completes in a given unit of time. This frequency directly correlates to the perceived pitch of the sound. Higher frequencies result in higher-pitched sounds, while lower frequencies result in lower-pitched sounds. Therefore, the correct answer is "Pitch."

Explanation

The frequency of a sound wave refers to the number of cycles or vibrations the wave completes in a given unit of time. This frequency directly correlates to the perceived pitch of the sound. Higher frequencies result in higher-pitched sounds, while lower frequencies result in lower-pitched sounds. Therefore, the correct answer is "Pitch."

22. The outer ear in sound localisation will catch more high frequency sounds easily from the front

True

False

The outer ear, also known as the pinna, plays a crucial role in sound localization. Its unique shape and structure help in capturing and funneling sound waves into the ear canal. The shape of the pinna allows it to effectively amplify high-frequency sounds coming from the front, making it easier to locate the source of these sounds. This is because high-frequency sounds have shorter wavelengths and are more easily affected by the shape of the pinna. Therefore, the statement that the outer ear catches more high-frequency sounds easily from the front is true.

Explanation

The outer ear, also known as the pinna, plays a crucial role in sound localization. Its unique shape and structure help in capturing and funneling sound waves into the ear canal. The shape of the pinna allows it to effectively amplify high-frequency sounds coming from the front, making it easier to locate the source of these sounds. This is because high-frequency sounds have shorter wavelengths and are more easily affected by the shape of the pinna. Therefore, the statement that the outer ear catches more high-frequency sounds easily from the front is true.

23. The osseous and membranous labyrinths both contain fluid, but which labyrinth contains which fluid?

Osseous labyrinth

Membranous labyrinth

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24. The stapes pushes against the ___________ which causes the fluid in the cochlea to vibrate at the same frequency as the sound and sets up a travelling wave.

The stapes, which is the smallest bone in the human body, pushes against the oval window. This action causes the fluid in the cochlea, a spiral-shaped structure in the inner ear, to vibrate at the same frequency as the sound. As a result, a traveling wave is set up in the cochlea, which is crucial for the process of hearing.

Explanation

The stapes, which is the smallest bone in the human body, pushes against the oval window. This action causes the fluid in the cochlea, a spiral-shaped structure in the inner ear, to vibrate at the same frequency as the sound. As a result, a traveling wave is set up in the cochlea, which is crucial for the process of hearing.

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25. There are two kinds of hair cells in the organ of Corti: inner (IHC) and outer hair cells (OHC). How many rows of IHCs and OHCs does the human ear generally have?

IHCs

OHCs

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26. The basilar membrane forms the upper boundary of the scala media.

True

False

It forms the LOWER boundary of the scala media. The UPPER boundary is called the vestibular or Reissner's membrane.

Explanation

It forms the LOWER boundary of the scala media. The UPPER boundary is called the vestibular or Reissner's membrane.

27. What is the non-acoustic function of the outer ear?

To protect against against assault and injury

To increase the length of the inner ear

To ensure alignment within the skull

To monitor balance and proprioception

The outer ear serves as a physical barrier that helps protect the delicate structures of the middle and inner ear from external harm. It consists of the pinna and the ear canal, which act as a shield, preventing foreign objects from entering the ear and potentially causing damage. Additionally, the shape and positioning of the outer ear help in localizing sound sources and enhancing sound reception, but this is not mentioned in the given options.

Explanation

The outer ear serves as a physical barrier that helps protect the delicate structures of the middle and inner ear from external harm. It consists of the pinna and the ear canal, which act as a shield, preventing foreign objects from entering the ear and potentially causing damage. Additionally, the shape and positioning of the outer ear help in localizing sound sources and enhancing sound reception, but this is not mentioned in the given options.

28. ________ fibres connect predominantly to the OHCs. Each neuron connects to a number of OHCs.

Efferent

Afferent

This tells us that the hair cells are PERCEPTUAL.

Explanation

This tells us that the hair cells are PERCEPTUAL.

29. What would be the effect if the IHCs were intact, but the OHCs were not?

All of them

You wouldn't be able to hear quiet sounds

You wouldn't be able to hear closely tuned sounds

You wouldn't be able to hear muffled sounds

You would lose the ability to suppress loud sounds

You would lose the ability/struggle to tune out background noise

If the IHCs (inner hair cells) were intact but the OHCs (outer hair cells) were not, it would have multiple effects on hearing. The OHCs play a crucial role in amplifying and fine-tuning sounds before they reach the IHCs. Without the OHCs, the ability to hear quiet sounds would be compromised as they help in amplifying soft sounds. Additionally, closely tuned sounds would be difficult to hear as the OHCs contribute to the precise frequency discrimination. Hearing muffled sounds would also be a consequence as the OHCs help in enhancing the clarity and sharpness of sounds. Furthermore, the OHCs are responsible for suppressing loud sounds, so the ability to tolerate loud sounds would be lost. Lastly, tuning out background noise would become challenging without the OHCs' contribution.

Explanation

If the IHCs (inner hair cells) were intact but the OHCs (outer hair cells) were not, it would have multiple effects on hearing. The OHCs play a crucial role in amplifying and fine-tuning sounds before they reach the IHCs. Without the OHCs, the ability to hear quiet sounds would be compromised as they help in amplifying soft sounds. Additionally, closely tuned sounds would be difficult to hear as the OHCs contribute to the precise frequency discrimination. Hearing muffled sounds would also be a consequence as the OHCs help in enhancing the clarity and sharpness of sounds. Furthermore, the OHCs are responsible for suppressing loud sounds, so the ability to tolerate loud sounds would be lost. Lastly, tuning out background noise would become challenging without the OHCs' contribution.

30. The outer ear in sound localisation helps us to determine if sounds come from below or above.

True

False

The outer ear plays a crucial role in sound localization. Its unique shape and position allow it to capture sound waves from different angles, enabling us to determine the direction from which a sound is coming. By comparing the slight differences in sound arrival time and intensity between the ears, our brain can accurately locate the source of the sound in three-dimensional space. This ability also helps us determine if sounds come from below or above, making the statement "The outer ear in sound localization helps us to determine if sounds come from below or above" true.

Explanation

The outer ear plays a crucial role in sound localization. Its unique shape and position allow it to capture sound waves from different angles, enabling us to determine the direction from which a sound is coming. By comparing the slight differences in sound arrival time and intensity between the ears, our brain can accurately locate the source of the sound in three-dimensional space. This ability also helps us determine if sounds come from below or above, making the statement "The outer ear in sound localization helps us to determine if sounds come from below or above" true.

31. In general, the lower the amplitude, the louder the sound.

True

False

The higher the amplitude, the louder the sound. Amplitude is physical, loudness is subjective.

Explanation

The higher the amplitude, the louder the sound. Amplitude is physical, loudness is subjective.

32. Outer hair cells are '_______' participants in the mechanoelectric transduction process.

Active

Passive

At the specific region of the basilar membrane most tuned to the incoming sound frequency, the OHC EXPAND AND CONTRACT in direct response to the sound, imparting energy into the system.

This exaggerates the motion between the basilar and tectorial membranes; hence the IHC stereocilia are displaced more vigorously, increasing the stimulation of the IHCs.

Explanation

At the specific region of the basilar membrane most tuned to the incoming sound frequency, the OHC EXPAND AND CONTRACT in direct response to the sound, imparting energy into the system.

This exaggerates the motion between the basilar and tectorial membranes; hence the IHC stereocilia are displaced more vigorously, increasing the stimulation of the IHCs.

33. Excited OHCs react by ___________.

Contracting

Expanding

This active mechanism pulls the BASILAR and TECTORIAL MEMBRANES together and apart more vigorously, resulting in further stimulation of the IHCs.

Explanation

This active mechanism pulls the BASILAR and TECTORIAL MEMBRANES together and apart more vigorously, resulting in further stimulation of the IHCs.

34. Sound waves are collected by the

Pinna

External Auditory Meatus

Tympanic Membrane

Oval WIndow

They are collected by the pinna and then funnelled down through the EAM to the TM

Explanation

They are collected by the pinna and then funnelled down through the EAM to the TM

35. The fibrous layer of the tympanic membrane extends throughout the pars tensa, but not the pars flaccida.

True

False

The fibrous layer of the tympanic membrane extends throughout the pars tensa, which is the thicker and more rigid part of the eardrum. However, it does not extend into the pars flaccida, which is a smaller and more flexible part of the eardrum. This is why the statement is true, as the fibrous layer is present in one part of the eardrum but not the other.

Explanation

The fibrous layer of the tympanic membrane extends throughout the pars tensa, which is the thicker and more rigid part of the eardrum. However, it does not extend into the pars flaccida, which is a smaller and more flexible part of the eardrum. This is why the statement is true, as the fibrous layer is present in one part of the eardrum but not the other.

36. How many afferent neurons connect to IHCs?

95%

76%

82%

69%

Most EFFERENT connections are to OHCs.

Explanation

Most EFFERENT connections are to OHCs.

37. The Eustachian Tube is 36mm long and comprises of 2 parts. Match each part with its anatomy.

Osseous portion

Cartilaginous portion

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38. Where is the inner ear situated?

Within the temporal bone

Next to the sphenoid bone

Between the temporal and sphenoid bones

Behind the ethmoid bone

The inner ear is situated within the temporal bone. The temporal bone is a paired bone that forms part of the skull and is located on the sides and base of the skull. It houses various structures of the inner ear, including the cochlea, vestibule, and semicircular canals. These structures are responsible for hearing and balance.

Explanation

The inner ear is situated within the temporal bone. The temporal bone is a paired bone that forms part of the skull and is located on the sides and base of the skull. It houses various structures of the inner ear, including the cochlea, vestibule, and semicircular canals. These structures are responsible for hearing and balance.

39. Sound waves travel as alternate regions of high and low pressure. Match the terminology to its definition.

Compressions

Rarefactions

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40. The cochlea is adult-sized at birth.

True

False

The Organ of Corti is generally organised in an adult-like way by the second trimester of pregnancy.

Explanation

The Organ of Corti is generally organised in an adult-like way by the second trimester of pregnancy.

41. The OHCs stiffen in response to loud sounds to suppress the level of stimulation and so increase the dynamic range of hearing.

True

False

It cushions us against very loud sounds!

This action is fine-tuned by the EFFERENT input to the OHCs.

Explanation

It cushions us against very loud sounds!

This action is fine-tuned by the EFFERENT input to the OHCs.

42. The stereocilia of the OHCs, implanted in the tectorial membrane, are bent and the hair cell is depolarised.

True

False

The stereocilia of the OHCs, which are located in the tectorial membrane, are bent when the hair cell is depolarized. This suggests that the statement is true. When the stereocilia are bent, it allows for the transmission of sound signals to the brain. Therefore, the bending of the stereocilia in response to depolarization is an important mechanism in the auditory system.

Explanation

The stereocilia of the OHCs, which are located in the tectorial membrane, are bent when the hair cell is depolarized. This suggests that the statement is true. When the stereocilia are bent, it allows for the transmission of sound signals to the brain. Therefore, the bending of the stereocilia in response to depolarization is an important mechanism in the auditory system.

43. These two passages (scala vestibuli and scala tympani) are joined via a communicating opening between them at the apex. What is the apex called?

Helicotrema

Spiral lamina

Organ of Corti

Endolymph

The apex of the scala vestibuli and scala tympani is called the helicotrema. The helicotrema is a small opening that connects the two passages, allowing fluid to flow between them. This opening plays a crucial role in maintaining the balance of fluid pressure within the cochlea, which is important for proper hearing function. The other options listed - spiral lamina, organ of Corti, and endolymph - are all structures within the cochlea, but they are not specifically related to the apex or the connection between the scala vestibuli and scala tympani.

Explanation

The apex of the scala vestibuli and scala tympani is called the helicotrema. The helicotrema is a small opening that connects the two passages, allowing fluid to flow between them. This opening plays a crucial role in maintaining the balance of fluid pressure within the cochlea, which is important for proper hearing function. The other options listed - spiral lamina, organ of Corti, and endolymph - are all structures within the cochlea, but they are not specifically related to the apex or the connection between the scala vestibuli and scala tympani.

44. Approximately how long is the external auditory meatus in adults?

2.5cm

1.5cm

0.5cm

3.5cm

The external auditory meatus, also known as the ear canal, is approximately 2.5cm long in adults. This is the passage that leads from the outer ear to the middle ear. It is responsible for transmitting sound waves to the eardrum, allowing us to hear.

Explanation

The external auditory meatus, also known as the ear canal, is approximately 2.5cm long in adults. This is the passage that leads from the outer ear to the middle ear. It is responsible for transmitting sound waves to the eardrum, allowing us to hear.

45. Approximately how much larger is the tympanic membrane than the stapes footplate (which bangs against the oval window)?

17 times

13 times

25 times

9 times

Because the eardrum has a surface area approximately 17 times larger than the stapes footplate, the sound pressure at the footplate is 17 times greater than pressure at the eardrum due to the difference in surface area.

Explanation

Because the eardrum has a surface area approximately 17 times larger than the stapes footplate, the sound pressure at the footplate is 17 times greater than pressure at the eardrum due to the difference in surface area.

46. The cochlea resembles a snail shell with 2.5 turns (in humans). What is the central conical core of the cochlea called?

Modiolus

Helicotrema

Basilar membrane

Organ of Corti

The outer wall of the modiolus forms the inner wall of a canal which spirals the full 2.5 turns around the central core.

Explanation

The outer wall of the modiolus forms the inner wall of a canal which spirals the full 2.5 turns around the central core.

47. Sound originated through a vibrating source and is propagated through a

Sound is a form of energy that is produced when a source, such as a vibrating object, causes particles in a medium to vibrate. These vibrations then travel through the medium, which can be a solid, liquid, or gas, in the form of waves. The medium acts as a pathway for the sound waves to travel from the source to our ears, allowing us to perceive and hear the sound. Without a medium, such as air or water, sound waves cannot propagate and would not be able to reach our ears.

Explanation

Sound is a form of energy that is produced when a source, such as a vibrating object, causes particles in a medium to vibrate. These vibrations then travel through the medium, which can be a solid, liquid, or gas, in the form of waves. The medium acts as a pathway for the sound waves to travel from the source to our ears, allowing us to perceive and hear the sound. Without a medium, such as air or water, sound waves cannot propagate and would not be able to reach our ears.

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48. The outer ear consists of the

Pinna

External Auditory Meatus

Oval Window

Tympanic membrane

Pars tensa

Pars flaccida

The correct answer is Pinna, External Auditory Meatus. The outer ear is the visible part of the ear and is responsible for collecting sound waves. The pinna, also known as the auricle, is the fleshy, cartilaginous part of the outer ear that helps to direct sound waves into the ear canal. The external auditory meatus, also known as the ear canal, is the tube-like structure that leads from the pinna to the middle ear. It is lined with hair and wax-producing glands to protect the ear from foreign objects and infections. Together, the pinna and external auditory meatus play a crucial role in the process of hearing.

Explanation

The correct answer is Pinna, External Auditory Meatus. The outer ear is the visible part of the ear and is responsible for collecting sound waves. The pinna, also known as the auricle, is the fleshy, cartilaginous part of the outer ear that helps to direct sound waves into the ear canal. The external auditory meatus, also known as the ear canal, is the tube-like structure that leads from the pinna to the middle ear. It is lined with hair and wax-producing glands to protect the ear from foreign objects and infections. Together, the pinna and external auditory meatus play a crucial role in the process of hearing.

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49. The primary auditory pathway is contralateralised. Which ear has an advantage for speech?

Right

Left

The primary auditory pathway is contralateralized, meaning that sound information from one ear is primarily processed in the opposite hemisphere of the brain. Since the left hemisphere of the brain is dominant for language processing in most individuals, the right ear has an advantage for speech perception. This is known as the right ear advantage, where the right ear has better access to the language-processing areas of the brain, leading to better speech perception and understanding.

Explanation

The primary auditory pathway is contralateralized, meaning that sound information from one ear is primarily processed in the opposite hemisphere of the brain. Since the left hemisphere of the brain is dominant for language processing in most individuals, the right ear has an advantage for speech perception. This is known as the right ear advantage, where the right ear has better access to the language-processing areas of the brain, leading to better speech perception and understanding.

50. Match the following terms to their definition.

Long wavelength

Short wavelength

Infrasound

Ultrasound

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51. What is the name of the auditory receptor organ which sits on the basilar membrane?

The auditory receptor organ that sits on the basilar membrane is called the Organ of Corti. This organ is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. It contains specialized hair cells that are sensitive to different frequencies of sound, allowing us to perceive a wide range of auditory stimuli.

Explanation

The auditory receptor organ that sits on the basilar membrane is called the Organ of Corti. This organ is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. It contains specialized hair cells that are sensitive to different frequencies of sound, allowing us to perceive a wide range of auditory stimuli.

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52. How long is the Eustachian tube at birth?

17mm

20mm

23mm

35mm

The Eustachian tube is a narrow passage that connects the middle ear to the back of the throat. At birth, the Eustachian tube is approximately 17mm in length. As a child grows, the Eustachian tube also elongates, reaching its adult length of around 35mm. The length of the Eustachian tube is important for maintaining proper pressure and drainage in the middle ear, preventing issues such as ear infections.

Explanation

The Eustachian tube is a narrow passage that connects the middle ear to the back of the throat. At birth, the Eustachian tube is approximately 17mm in length. As a child grows, the Eustachian tube also elongates, reaching its adult length of around 35mm. The length of the Eustachian tube is important for maintaining proper pressure and drainage in the middle ear, preventing issues such as ear infections.

53. The cochlear duct runs between the the scala vestibuli and scala tympani. What is the cochlear duct called when in cross-section?

The cochlear duct, also known as the scala media, is the middle chamber of the cochlea in the inner ear. It is located between the scala vestibuli and the scala tympani. The scala media contains the organ of Corti, which is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain.

Explanation

The cochlear duct, also known as the scala media, is the middle chamber of the cochlea in the inner ear. It is located between the scala vestibuli and the scala tympani. The scala media contains the organ of Corti, which is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain.

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54. How long is the Eustachian tube as an adult?

36mm

27mm

32mm

30mm

The Eustachian tube in an adult is typically 36mm long. This tube connects the middle ear to the back of the throat and helps regulate pressure in the ear. It also allows for the drainage of fluids from the middle ear.

Explanation

The Eustachian tube in an adult is typically 36mm long. This tube connects the middle ear to the back of the throat and helps regulate pressure in the ear. It also allows for the drainage of fluids from the middle ear.

55. What would be the effect if no IHCs were intact?

You would be completely deaf

You wouldn't be able to hear quiet sounds

You wouldn't be able to hear loud sounds

You would lose the ability/struggle to tune out background noise

If no IHCs (inner hair cells) were intact, it means that the hair cells responsible for converting sound vibrations into electrical signals would be damaged or non-functional. These hair cells are essential for transmitting auditory information to the brain. Without functioning IHCs, the brain would not receive any sound signals, resulting in a complete loss of hearing.

Explanation

If no IHCs (inner hair cells) were intact, it means that the hair cells responsible for converting sound vibrations into electrical signals would be damaged or non-functional. These hair cells are essential for transmitting auditory information to the brain. Without functioning IHCs, the brain would not receive any sound signals, resulting in a complete loss of hearing.

56. Match the fluids to their components

Perilymph

Endolymph

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57. Approximately how many OHCs does the human ear have?

12,000

10,000

15,500

17,500

The human ear has approximately 12,000 OHCs. OHCs, or outer hair cells, are specialized sensory cells in the cochlea of the inner ear. These cells play a crucial role in amplifying sound waves and enhancing the sensitivity and precision of hearing. The large number of OHCs in the human ear allows for a wide range of auditory perception and helps in distinguishing different pitches and frequencies of sound.

Explanation

The human ear has approximately 12,000 OHCs. OHCs, or outer hair cells, are specialized sensory cells in the cochlea of the inner ear. These cells play a crucial role in amplifying sound waves and enhancing the sensitivity and precision of hearing. The large number of OHCs in the human ear allows for a wide range of auditory perception and helps in distinguishing different pitches and frequencies of sound.

58. The amplitude of a sound wave relates to the changes above and below atmospheric pressure. What is this change called?

Displacement

Frequency

Pitch

Transient

The correct answer is Displacement. The amplitude of a sound wave refers to the maximum distance that particles in the medium (such as air) are displaced from their equilibrium position as the wave passes through. It is a measure of the intensity or loudness of the sound. So, the change in pressure above and below atmospheric pressure is called displacement.

Explanation

The correct answer is Displacement. The amplitude of a sound wave refers to the maximum distance that particles in the medium (such as air) are displaced from their equilibrium position as the wave passes through. It is a measure of the intensity or loudness of the sound. So, the change in pressure above and below atmospheric pressure is called displacement.

59. Approximately how many IHCs does the human ear have?

3500

2700

3300

4600

The correct answer is 3500. IHCs, or Inner Hair Cells, are sensory cells located in the cochlea of the human ear. They play a crucial role in converting sound vibrations into electrical signals that can be interpreted by the brain. The human ear typically has around 3500 IHCs, which are responsible for transmitting auditory information to the brain for processing and perception of sound.

Explanation

The correct answer is 3500. IHCs, or Inner Hair Cells, are sensory cells located in the cochlea of the human ear. They play a crucial role in converting sound vibrations into electrical signals that can be interpreted by the brain. The human ear typically has around 3500 IHCs, which are responsible for transmitting auditory information to the brain for processing and perception of sound.

60. Motion of the basilar membrane, under the influence of sound, results in a shearing motion between the stereocilia of the _______________ and tectorial membrane, opening ion channels so that the flow of potassium ions from the endolymph into the hair cells increases. The cell depolarises and a signal is sent up the auditory pathway to the auditory nerve, and you hear the sound.

Inner hair cells

Outer hair cells

Under the influence of sound, the motion of the basilar membrane causes a shearing motion between the stereocilia of the inner hair cells and the tectorial membrane. This shearing motion opens ion channels, allowing an increased flow of potassium ions from the endolymph into the hair cells. This influx of potassium ions depolarizes the cell, leading to the generation of an electrical signal. This signal is then transmitted up the auditory pathway to the auditory nerve, which ultimately results in the perception of sound. The outer hair cells, on the other hand, play a role in amplifying and fine-tuning the sound signals received by the inner hair cells.

Explanation

Under the influence of sound, the motion of the basilar membrane causes a shearing motion between the stereocilia of the inner hair cells and the tectorial membrane. This shearing motion opens ion channels, allowing an increased flow of potassium ions from the endolymph into the hair cells. This influx of potassium ions depolarizes the cell, leading to the generation of an electrical signal. This signal is then transmitted up the auditory pathway to the auditory nerve, which ultimately results in the perception of sound. The outer hair cells, on the other hand, play a role in amplifying and fine-tuning the sound signals received by the inner hair cells.

61. The portion of the membranous labyrinth within the cochlea is called the cochlear duct, or in cross section...?

Scala media

Scala tympani

Scala vestibuli

Spiral lamina

The portion of the membranous labyrinth within the cochlea is called the cochlear duct, or in cross section, the scala media.

Explanation

The portion of the membranous labyrinth within the cochlea is called the cochlear duct, or in cross section, the scala media.

62. IHCs are innervated by ________________ and by a few efferent neurons.

Myelinated type 1 afferent neurons

Unmyelinated type 1 afferent neurons

Myelinated type 2 afferent neurons

Unmyelinated type 2 afferent neurons

IHCs, or inner hair cells, are innervated by myelinated type 1 afferent neurons. These neurons transmit signals from the IHCs to the brain, allowing us to perceive sound. The myelination of these neurons helps to increase the speed and efficiency of signal transmission. Additionally, a few efferent neurons also innervate IHCs, allowing for feedback and modulation of the auditory system.

Explanation

IHCs, or inner hair cells, are innervated by myelinated type 1 afferent neurons. These neurons transmit signals from the IHCs to the brain, allowing us to perceive sound. The myelination of these neurons helps to increase the speed and efficiency of signal transmission. Additionally, a few efferent neurons also innervate IHCs, allowing for feedback and modulation of the auditory system.

63. Sound will travel through space.

True

False

Sound will not travel through space as there is no medium for it to travel through!

Explanation

Sound will not travel through space as there is no medium for it to travel through!

64. How does the external ear assist in sound localisations?

By producing spectral modulations of incoming sounds

By changing the internal structure of the middle and inner ears to turn towards the sound

By converting the incoming signal into information which the brain processes as sound

Because there is a reduction in the level of higher frequency sounds (3-6kHz region) that reach the tympanic membrane when the sound source is behind the ear, relative to when the level when the source is in front of the ear

Explanation

Because there is a reduction in the level of higher frequency sounds (3-6kHz region) that reach the tympanic membrane when the sound source is behind the ear, relative to when the level when the source is in front of the ear

65. Growth of the Eustachian tube is rapid, and for those who experience middle ear problems, many get better after which age?

6

9

4

5

The growth of the Eustachian tube is rapid, and for those who experience middle ear problems, many get better after the age of 6. This suggests that as children grow older, their Eustachian tubes develop and function more effectively, reducing the likelihood of middle ear problems.

Explanation

The growth of the Eustachian tube is rapid, and for those who experience middle ear problems, many get better after the age of 6. This suggests that as children grow older, their Eustachian tubes develop and function more effectively, reducing the likelihood of middle ear problems.

66. Approximately how much longer is the arm of the malleus compared with that of the incus?

1.3 times

3.5 times

2.7 times

4.1 times

This results in a lever action that increases the force and produces a 1.3 factor increase in pressure at the oval window.

Explanation

This results in a lever action that increases the force and produces a 1.3 factor increase in pressure at the oval window.

67. Auditory pathways from the brainstem to the auditory cortex develop more slowly, and are not considered to be fully mature until approximately what age?

6 years

4 years

7 years

5 years

The auditory pathways from the brainstem to the auditory cortex refer to the neural connections responsible for processing sound information. These pathways develop gradually over time and are not considered to be fully mature until around the age of 6. This means that children's ability to perceive and interpret sound continues to improve until this age.

Explanation

The auditory pathways from the brainstem to the auditory cortex refer to the neural connections responsible for processing sound information. These pathways develop gradually over time and are not considered to be fully mature until around the age of 6. This means that children's ability to perceive and interpret sound continues to improve until this age.

68. The outer ear will catch more low frequency sounds easily from the front

True

False

The outer ear will catch more HIGH frequency sounds easily from the front

Explanation

The outer ear will catch more HIGH frequency sounds easily from the front

69. What is the average hearing threshold for young, healthy ears?

0dB

-5dB

5dB

10dB

This is also the softest sound which can be heard

Explanation

This is also the softest sound which can be heard

70. Which are the two most important cues for sound localisation in people?

Intensity differences at the two ears

Timing differences at the two ears

Pitch differences at the two ears

Fundamental frequency differences at the two ears

The two most important cues for sound localization in people are intensity differences at the two ears and timing differences at the two ears. Intensity differences refer to the difference in loudness of a sound reaching each ear, which allows the brain to determine the direction of the sound source. Timing differences, on the other hand, refer to the slight delay in the arrival of a sound at one ear compared to the other, which helps the brain determine the location of the sound source. These two cues work together to provide accurate sound localization.

Explanation

The two most important cues for sound localization in people are intensity differences at the two ears and timing differences at the two ears. Intensity differences refer to the difference in loudness of a sound reaching each ear, which allows the brain to determine the direction of the sound source. Timing differences, on the other hand, refer to the slight delay in the arrival of a sound at one ear compared to the other, which helps the brain determine the location of the sound source. These two cues work together to provide accurate sound localization.

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71. Coming from the brain, descending nerve fibres carry instructions from the brain back to the ear (mainly ______________) to suppress some signals which the brain considers to be unimportant and therefore concentrate on others. This helps the listener to focus on what they wish to listen to.

Outer hair cells

Inner hair cells

Descending nerve fibers carry instructions from the brain back to the ear, mainly to the outer hair cells, to suppress some signals that the brain considers unimportant. This allows the brain to concentrate on other signals that are deemed important, helping the listener to focus on what they wish to listen to.

Explanation

Descending nerve fibers carry instructions from the brain back to the ear, mainly to the outer hair cells, to suppress some signals that the brain considers unimportant. This allows the brain to concentrate on other signals that are deemed important, helping the listener to focus on what they wish to listen to.

72. The outer ear is an acoustic cavity which resonates, and resonances of the pinna and meatus help to increase the sound pressure at the tympanic membrane. The peak of this pressure gain occurs at which frequency and approximates to how many dB?

2-5k Hz; 15-20dB

2-6k Hz; 10-20dB

1-5k Hz; 15-20dB

1-6k Hz; 10-20dB

2-5k Hz; 15-20dB - therefore, human hearing is most sensitive at these frequencies!

Explanation

2-5k Hz; 15-20dB - therefore, human hearing is most sensitive at these frequencies!

73. OHCs are innervated by a few _________________ and by efferent neurons.

Unmyelinated type 2 afferent neurons

Myelinated type 2 afferent neurons

Unmyelinated type 1 afferent neurons

Myelinated type 1 afferent neurons

OHCs (Outer Hair Cells) are innervated by unmyelinated type 2 afferent neurons. These neurons transmit sensory information from the OHCs to the central nervous system. Unlike myelinated neurons, unmyelinated neurons do not have a myelin sheath, which allows for faster transmission of electrical signals. Type 2 afferent neurons specifically innervate OHCs and play a role in the amplification and modulation of sound signals in the cochlea.

Explanation

OHCs (Outer Hair Cells) are innervated by unmyelinated type 2 afferent neurons. These neurons transmit sensory information from the OHCs to the central nervous system. Unlike myelinated neurons, unmyelinated neurons do not have a myelin sheath, which allows for faster transmission of electrical signals. Type 2 afferent neurons specifically innervate OHCs and play a role in the amplification and modulation of sound signals in the cochlea.

74. The inner ear contains 6 mechanoreceptive structures: 3 semi-circular canals, utricle and saccule, and the cochlea. What is the purpose of the saccule?

Serves the sense of equilibrium

Serves the sense of balance

Serves the notion of uncomfortable loudness

Serves the notion of directionality

E.g., you can tell you're accelerating, even with your eyes closed!

Explanation

E.g., you can tell you're accelerating, even with your eyes closed!

75. The cochlea is both highly frequency selective and able to process a very large range of acoustic pressure which enter the ear. Approximately how many different pitches can the cochlea hear?

1500

2100

1700

3250

The cochlea is a part of the inner ear that is responsible for hearing. It is highly frequency selective, meaning it can distinguish between different pitches. Additionally, it is able to process a wide range of acoustic pressure that enters the ear. The number of different pitches that the cochlea can hear is approximately 1500.

Explanation

The cochlea is a part of the inner ear that is responsible for hearing. It is highly frequency selective, meaning it can distinguish between different pitches. Additionally, it is able to process a wide range of acoustic pressure that enters the ear. The number of different pitches that the cochlea can hear is approximately 1500.

76. One of the consequences of the active movement of the OHCs is that the cochlea produces ______________ emissions.

It was discovered that in response to a brief sound, there appeared (in the ear canal) a second, brief, time-delayed sound - a copy of the first!

Explanation

It was discovered that in response to a brief sound, there appeared (in the ear canal) a second, brief, time-delayed sound - a copy of the first!

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77. Displacement is often quoted in

DB

Hz

F0

Fx

Displacement refers to the perceived loudness of a sound

Explanation

Displacement refers to the perceived loudness of a sound

78. Different sets of auditory nerve fibres elicit different auditory sensations in the auditory cortex. Some auditory nerve fibres carry low frequency sounds, others carry high frequency sounds. What is the frequency at which a fibre is most sensitive?

Characteristic frequency

Fundamental frequency

Formant frequency

Sampling frequency

The characteristic frequency of a fibre is dependent on the LOCATION along the basilar membrane of the hair cell to which it is attached.

Explanation

The characteristic frequency of a fibre is dependent on the LOCATION along the basilar membrane of the hair cell to which it is attached.

79. Sound waves move the __________________ up and down in the form of a travelling wave.

Sound waves move the basilar membrane up and down in the form of a traveling wave. The basilar membrane is a structure located in the cochlea of the inner ear. When sound waves enter the ear, they cause vibrations in the basilar membrane. These vibrations are then transmitted to the hair cells, which convert the mechanical energy of the sound waves into electrical signals that can be interpreted by the brain. Therefore, the movement of the basilar membrane is crucial for the perception of sound.

Explanation

Sound waves move the basilar membrane up and down in the form of a traveling wave. The basilar membrane is a structure located in the cochlea of the inner ear. When sound waves enter the ear, they cause vibrations in the basilar membrane. These vibrations are then transmitted to the hair cells, which convert the mechanical energy of the sound waves into electrical signals that can be interpreted by the brain. Therefore, the movement of the basilar membrane is crucial for the perception of sound.

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80. What are the acoustic characteristics and functions of the outer ear?

To collect sound

To increase sound pressure at the tympanic membrane by generating resonances

To aid in sound localisation

To aid in balance and proprioception

The outer ear has several acoustic characteristics and functions. Firstly, it helps to collect sound by acting as a funnel, directing sound waves towards the ear canal. Secondly, it increases sound pressure at the tympanic membrane by generating resonances, which helps in amplifying the sound. Thirdly, the outer ear aids in sound localization by helping to determine the direction and location of the sound source. Lastly, it also plays a role in balance and proprioception, helping us maintain our equilibrium and sense the position of our body in space.

Explanation

The outer ear has several acoustic characteristics and functions. Firstly, it helps to collect sound by acting as a funnel, directing sound waves towards the ear canal. Secondly, it increases sound pressure at the tympanic membrane by generating resonances, which helps in amplifying the sound. Thirdly, the outer ear aids in sound localization by helping to determine the direction and location of the sound source. Lastly, it also plays a role in balance and proprioception, helping us maintain our equilibrium and sense the position of our body in space.

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81. Approximately how long is the tympanic membrane?

8-10mm

4-6mm

6-10mm

8-12mm

It is made up of a thin, fibrous layer covered by skin on the outside, and mucosa on the internal surface

Explanation

It is made up of a thin, fibrous layer covered by skin on the outside, and mucosa on the internal surface

82. Which of the following is the correct general positioning of the Eustachian tube from the anterior wall of the tympanic cavity?

Downwards, forwards, and medially

Upwards, forwards, and medially

Downwards, backwards, and medially

Upwards, backwards, and medially

The Eustachian tube is positioned downwards, forwards, and medially from the anterior wall of the tympanic cavity. This positioning allows for the proper drainage of fluids from the middle ear into the nasopharynx, helping to maintain equal pressure on both sides of the eardrum.

Explanation

The Eustachian tube is positioned downwards, forwards, and medially from the anterior wall of the tympanic cavity. This positioning allows for the proper drainage of fluids from the middle ear into the nasopharynx, helping to maintain equal pressure on both sides of the eardrum.

83. Which of the following are functions of the middle ear?

To transform acoustic energy in air at the tympanic membrane to acoustic energy in the fluids of the cochlea

To increase the efficiency of sound energy transfer to the cochlea by increasing the sound pressure at the oval window

To collect the sound waves and amplify them enough to force the tympanic membrane to vibrate

To distribute the sound waves up to the brain via the auditory nerve

The middle ear serves multiple functions in the process of hearing. One of its main functions is to transform acoustic energy in air at the tympanic membrane to acoustic energy in the fluids of the cochlea. This transformation allows the sound waves to be transmitted from the outer ear to the inner ear, where they can be processed and interpreted by the brain. Additionally, the middle ear helps increase the efficiency of sound energy transfer to the cochlea by increasing the sound pressure at the oval window. This amplification helps to enhance the perception of sound and improve overall hearing sensitivity.

Explanation

The middle ear serves multiple functions in the process of hearing. One of its main functions is to transform acoustic energy in air at the tympanic membrane to acoustic energy in the fluids of the cochlea. This transformation allows the sound waves to be transmitted from the outer ear to the inner ear, where they can be processed and interpreted by the brain. Additionally, the middle ear helps increase the efficiency of sound energy transfer to the cochlea by increasing the sound pressure at the oval window. This amplification helps to enhance the perception of sound and improve overall hearing sensitivity.

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84. A thin shelf of bone which projects from the modiolus and partially divides the canal into two parts along its entire length is called the...

Spiral lamina

Helicotrema

Apex

Spiral ganglion

The correct answer is Spiral lamina. The spiral lamina is a thin shelf of bone that extends from the modiolus, which is the central core of the cochlea. It partially divides the cochlear canal into two parts along its entire length. This structure plays a crucial role in supporting the organ of Corti, which is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain.

Explanation

The correct answer is Spiral lamina. The spiral lamina is a thin shelf of bone that extends from the modiolus, which is the central core of the cochlea. It partially divides the cochlear canal into two parts along its entire length. This structure plays a crucial role in supporting the organ of Corti, which is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain.

85. Sound energy travels along the _____________ in the form of a travelling wave.

Sound energy travels along the basilar membrane in the form of a traveling wave. The basilar membrane is a thin, flexible membrane located in the inner ear. When sound waves enter the ear, they cause the basilar membrane to vibrate. These vibrations are then transmitted to the hair cells, which convert the mechanical energy into electrical signals that can be interpreted by the brain as sound. Therefore, the basilar membrane plays a crucial role in the transmission of sound energy within the ear.

Explanation

Sound energy travels along the basilar membrane in the form of a traveling wave. The basilar membrane is a thin, flexible membrane located in the inner ear. When sound waves enter the ear, they cause the basilar membrane to vibrate. These vibrations are then transmitted to the hair cells, which convert the mechanical energy into electrical signals that can be interpreted by the brain as sound. Therefore, the basilar membrane plays a crucial role in the transmission of sound energy within the ear.

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86. How many nerve fibres form the auditory nerve?

30,000

25,000

45,000

50,000

The auditory nerve is composed of approximately 30,000 nerve fibers. These fibers carry electrical signals from the hair cells in the cochlea of the inner ear to the brain, allowing us to perceive and interpret sound.

Explanation

The auditory nerve is composed of approximately 30,000 nerve fibers. These fibers carry electrical signals from the hair cells in the cochlea of the inner ear to the brain, allowing us to perceive and interpret sound.

87. Approximately how long is a wavelength?

34cm

28cm

46cm

52cm

A wavelength refers to the distance between two corresponding points on a wave, such as the distance between two consecutive peaks or troughs. In this case, the correct answer is 34cm, which suggests that the wavelength being referred to is approximately 34 centimeters in length.

Explanation

A wavelength refers to the distance between two corresponding points on a wave, such as the distance between two consecutive peaks or troughs. In this case, the correct answer is 34cm, which suggests that the wavelength being referred to is approximately 34 centimeters in length.

88. By approximately how much less would we hear if we had no middle ear?

28dB

15dB

12dB

35dB

We would hear approximately 28dB less without a middle ear as the middle ear is essential for the transfer of sound waves from air to fluid. If the sound went straight from air to fluid, approximately 99% of the sound would be reflected away.

Explanation

We would hear approximately 28dB less without a middle ear as the middle ear is essential for the transfer of sound waves from air to fluid. If the sound went straight from air to fluid, approximately 99% of the sound would be reflected away.

89. The stereocilia of IHCs are straight and the hair cell fires, sending a signal towards the brain.

True

False

The stereocilia of IHCs are BENT

Explanation

The stereocilia of IHCs are BENT

90. Individual particles of the medium travel with the wave.

True

False

The particles vibrate back and forth around their equilibrium position, they do not move with the wave!

Explanation

The particles vibrate back and forth around their equilibrium position, they do not move with the wave!

91. Each location along the scala tympani responds best to a small range of sound frequencies.

True

False

Each location along the BASILAR MEMBRANE responds best to a small range of sound frequencies.

Explanation

Each location along the BASILAR MEMBRANE responds best to a small range of sound frequencies.

92. The cochlea is a long, coiled, fluid-filled tube which is divided along most of its length into scala vestibuli, scala, media, and scala tympani. When coiled, approximately how big is the cochlea?

9mm in diameter, 5mm in height

9mm in diameter, 3mm in height

7mm in diameter, 5mm in height

7mm in diameter, 3mm in height

The cochlea is approximately 9mm in diameter and 5mm in height.

Explanation

The cochlea is approximately 9mm in diameter and 5mm in height.

93. How long is the Eustachian tube at 6 years?

30mm

23mm

32mm

35mm

The Eustachian tube is a small passage that connects the middle ear to the back of the throat. It helps equalize the pressure between the middle ear and the atmosphere. The length of the Eustachian tube can vary depending on the age of the individual. At 6 years old, the length of the Eustachian tube is typically 30mm.

Explanation

The Eustachian tube is a small passage that connects the middle ear to the back of the throat. It helps equalize the pressure between the middle ear and the atmosphere. The length of the Eustachian tube can vary depending on the age of the individual. At 6 years old, the length of the Eustachian tube is typically 30mm.

94. At birth, the pharyngeal orifice is immediately above the soft palate. Where is the pharyngeal orifice in adults in relation to the soft palate?

10mm above

12mm below

5mm above

7mm above

In adults, the pharyngeal orifice is located 10mm above the soft palate. This means that it is positioned higher in relation to the soft palate compared to its location at birth.

Explanation

In adults, the pharyngeal orifice is located 10mm above the soft palate. This means that it is positioned higher in relation to the soft palate compared to its location at birth.

95. Some auditory nerve fibres have a high spontaneous firing rate and these primarily carry high level intensity sounds.

True

False

Some auditory nerve fibres have a HIGH spontaneous firing rate and these primarily carry LOW level intensity sounds.

Other fibres have a LOW spontaneous rate and code HIGH level intensity sounds.

Explanation

Some auditory nerve fibres have a HIGH spontaneous firing rate and these primarily carry LOW level intensity sounds.

Other fibres have a LOW spontaneous rate and code HIGH level intensity sounds.

96. Each increase of how many dB represents an approximate doubling of the perceived loudness of the sound?

10dB

5dB

15dB

20dB

Each increase of 10dB represents an approximate doubling of the perceived loudness of the sound. This is because the decibel scale is logarithmic, not linear. A 10dB increase means that the sound is 10 times more intense, which is equivalent to doubling the perceived loudness. Therefore, the correct answer is 10dB.

Explanation

Each increase of 10dB represents an approximate doubling of the perceived loudness of the sound. This is because the decibel scale is logarithmic, not linear. A 10dB increase means that the sound is 10 times more intense, which is equivalent to doubling the perceived loudness. Therefore, the correct answer is 10dB.

97. How much of a boost does the pinna give?

+5dB

+7dB

+10dB

+20dB

The pinna is the outer part of the ear that helps to collect sound waves and direct them into the ear canal. It acts as a natural amplifier by boosting the sound by approximately 5dB. This boost in volume allows us to better perceive and locate sounds in our environment.

Explanation

The pinna is the outer part of the ear that helps to collect sound waves and direct them into the ear canal. It acts as a natural amplifier by boosting the sound by approximately 5dB. This boost in volume allows us to better perceive and locate sounds in our environment.

98. What is generally the earliest cochlear implants can be inserted?

3 months

6 months

9 months

12 months

The youngest was 3 months!

Explanation

The youngest was 3 months!

99. Which 3 carry the intensity information of the nerve fibre carrying the signal?

Rate of firing

Number of nerve fibre

Type of nerve fibre

Size of nerve fibre

Elasticity of nerve fibre

As the amplitude of a sound increasesm the firing RATE increases and MORE FIBRES carry the signal

Explanation

As the amplitude of a sound increasesm the firing RATE increases and MORE FIBRES carry the signal

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100. The cochlea is gross mature by how many foetal weeks?

22-26

14-18

26-30

28-32

The cochlea is grossly mature by around 22-26 weeks of fetal development. This means that the structure of the cochlea, which is responsible for hearing, has reached a relatively advanced stage of development during this time period. The cochlea is a spiral-shaped structure in the inner ear that contains tiny hair cells that detect sound vibrations and send signals to the brain for interpretation. By 22-26 weeks, the cochlea has developed enough to begin processing sound information, although further refinement and maturation will continue after birth.

Explanation

The cochlea is grossly mature by around 22-26 weeks of fetal development. This means that the structure of the cochlea, which is responsible for hearing, has reached a relatively advanced stage of development during this time period. The cochlea is a spiral-shaped structure in the inner ear that contains tiny hair cells that detect sound vibrations and send signals to the brain for interpretation. By 22-26 weeks, the cochlea has developed enough to begin processing sound information, although further refinement and maturation will continue after birth.

101. Hair cells are flask-shaped (inner) or cylindrical (outer) and are equipped with a bundle of sensory hair cells which lie in a hexagonal array and increase in length from one edge of the hair bundle to the other. What are these sensory hair cells called?

Stereocilia consist of ACTIN FILAMENTS. These filaments are cross-bridged (with tip-links) and each stereocilium behaves like a stiff rod which pivots at its base - they are very rigid structures.

Explanation

Stereocilia consist of ACTIN FILAMENTS. These filaments are cross-bridged (with tip-links) and each stereocilium behaves like a stiff rod which pivots at its base - they are very rigid structures.

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102. Within the modiolus is a bundle of nerve fibres called the _________________. The central processes of these nerve fibres form the cochlear nerve.

The correct answer is spiral ganglion. The modiolus contains a bundle of nerve fibers known as the spiral ganglion. These nerve fibers have central processes that form the cochlear nerve. The spiral ganglion plays a crucial role in transmitting auditory information from the cochlea to the brain.

Explanation

The correct answer is spiral ganglion. The modiolus contains a bundle of nerve fibers known as the spiral ganglion. These nerve fibers have central processes that form the cochlear nerve. The spiral ganglion plays a crucial role in transmitting auditory information from the cochlea to the brain.

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103. Where does the auditory cortex lie?

Sylvanian fissure

Central sulcus

Temporal lobe

Cerebellum

The high tones terminate deep within the Sylvanian fissure while the low tones end near the outer surface.

Explanation

The high tones terminate deep within the Sylvanian fissure while the low tones end near the outer surface.

104. Hearing loss may affect...

Speech perception

Development of communication skills (both speech and language)

The ability to learn

Social skills

Cognitive development

Learning to write

Hearing loss can have a significant impact on various aspects of an individual's life. It can affect speech perception, making it difficult for individuals to understand and interpret spoken language. This, in turn, can hinder the development of communication skills, including both speech and language abilities. Hearing loss can also impact the ability to learn, as hearing is crucial for acquiring new knowledge and understanding instructions. Additionally, hearing loss can affect social skills, as it may make it challenging to engage in conversations and interact with others effectively. Lastly, hearing loss can have implications for cognitive development and learning to write, as hearing plays a crucial role in language and literacy development.

Explanation

Hearing loss can have a significant impact on various aspects of an individual's life. It can affect speech perception, making it difficult for individuals to understand and interpret spoken language. This, in turn, can hinder the development of communication skills, including both speech and language abilities. Hearing loss can also impact the ability to learn, as hearing is crucial for acquiring new knowledge and understanding instructions. Additionally, hearing loss can affect social skills, as it may make it challenging to engage in conversations and interact with others effectively. Lastly, hearing loss can have implications for cognitive development and learning to write, as hearing plays a crucial role in language and literacy development.

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105. Most afferent neurons have single-ending connections to IHCs. There are normally ___________ nerve fibres per IHC.

10-20

20-30

15-25

25-35

Most afferent neurons have single-ending connections to IHCs, meaning that each afferent neuron connects to only one inner hair cell (IHC). The question asks about the number of nerve fibers per IHC, and the correct answer is 10-20. This means that each IHC is typically connected to 10-20 nerve fibers, allowing for the transmission of auditory signals from the IHC to the brain.

Explanation

Most afferent neurons have single-ending connections to IHCs, meaning that each afferent neuron connects to only one inner hair cell (IHC). The question asks about the number of nerve fibers per IHC, and the correct answer is 10-20. This means that each IHC is typically connected to 10-20 nerve fibers, allowing for the transmission of auditory signals from the IHC to the brain.

106. When sound energy is introduced into the inner ear, the resultant up-and-down motion of the basilar membrane results in the cell firing in an all-or-nothing ______________.

All information about our acoustic environment is thus carried in trains of nerve impulses (action potentials) in bundles of auditory nerve fibres.

The auditory nerve fibres then carry the CODED AUDITORY INFORMATION to the brain.

Explanation

All information about our acoustic environment is thus carried in trains of nerve impulses (action potentials) in bundles of auditory nerve fibres.

The auditory nerve fibres then carry the CODED AUDITORY INFORMATION to the brain.

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107. When does the Eustachian tube close?

Yawning

Swallowing

Talking

Whispering

On an aircraft

Swimming

Listening to headphones

When closed, the Eustachian tube opens briefly, allowing air to enter the middle ear, replacing the air that has diffused into the mucous lining. This keeps the middle ear pressure the same as the atmospheric pressure.

Explanation

When closed, the Eustachian tube opens briefly, allowing air to enter the middle ear, replacing the air that has diffused into the mucous lining. This keeps the middle ear pressure the same as the atmospheric pressure.

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108. Which orifices are relatively wide in childhood?

Pharyngeal

Tympanic

Nasal

Aural

Vestibuli

During childhood, the orifices that are relatively wide are the Pharyngeal and Tympanic orifices. The pharyngeal orifice refers to the opening between the nasal cavity and the throat, while the tympanic orifice is the opening that connects the middle ear to the nasopharynx. These orifices are wider in childhood to accommodate the growth and development of the respiratory and auditory systems. As a person grows older, these orifices become narrower and more constricted.

Explanation

During childhood, the orifices that are relatively wide are the Pharyngeal and Tympanic orifices. The pharyngeal orifice refers to the opening between the nasal cavity and the throat, while the tympanic orifice is the opening that connects the middle ear to the nasopharynx. These orifices are wider in childhood to accommodate the growth and development of the respiratory and auditory systems. As a person grows older, these orifices become narrower and more constricted.

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109. The basilar membrane connects the thin shelf of bone (osseous spiral lamina) to the outer wall of the bony cochlea and thus separates the canal into two main passages. What are these 2 passages called?

The basilar membrane connects the osseous spiral lamina to the outer wall of the bony cochlea, creating two main passages within the canal. These passages are known as the scala vestibuli and scala tympani.

Explanation

The basilar membrane connects the osseous spiral lamina to the outer wall of the bony cochlea, creating two main passages within the canal. These passages are known as the scala vestibuli and scala tympani.

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110. The cochlea converts acoustic signals into the __________ which conveys auditory information to the brain.

The cochlea is a spiral-shaped structure in the inner ear that plays a crucial role in hearing. It converts acoustic signals, or sound waves, into electrical signals, which are then transmitted to the brain. These electrical signals, known as the neural code, carry auditory information to different areas of the brain for processing and interpretation. In this way, the cochlea acts as a transducer, transforming sound waves into a language that the brain can understand.

Explanation

The cochlea is a spiral-shaped structure in the inner ear that plays a crucial role in hearing. It converts acoustic signals, or sound waves, into electrical signals, which are then transmitted to the brain. These electrical signals, known as the neural code, carry auditory information to different areas of the brain for processing and interpretation. In this way, the cochlea acts as a transducer, transforming sound waves into a language that the brain can understand.

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