Hearing Science Study Quiz

Explanation
When the distance from a sound source is doubled, the sound level decreases by 6dB. In this case, the sound level at 2m would be 6dB lower than the sound level at 1m, which is 90dB. Therefore, the sound level at 2m would be 84dB.

Explanation
The sound pressure is a measure of the amplitude of a sound wave, indicating the amount of force exerted by the sound wave on a unit area. In this case, the sound pressure is given as .0002 dynes/cm^2, which means that for every square centimeter of area, the sound wave exerts a force of .0002 dynes. This value represents a very low sound pressure, suggesting that the sound wave is relatively weak or quiet.

Explanation
The correct answer is "a and b" because both triangular wave and square wave are complex periodic waveforms with energy at odd integral multiples of Fo. Triangular wave has energy at odd harmonics, while square wave has energy at all odd harmonics as well as the fundamental frequency. Sawtooth wave, on the other hand, has energy at all harmonics, not just odd multiples. Therefore, the correct answer is a combination of triangular wave and square wave.

Explanation
A harmonic spectrum refers to a spectrum in which the frequencies of the components are integer multiples of a fundamental frequency. This means that the components are related to each other by simple ratios. In other words, the harmonic spectrum consists of a series of harmonics that are evenly spaced. This is in contrast to a continuous spectrum, which includes all possible frequencies, or a line spectrum, which consists of only a few specific frequencies. Therefore, the correct answer is "harmonic".

Explanation
An octave is a component of a periodic sound wave that has a frequency which is exactly double or half of the fundamental pitch. It is called an octave because it spans eight notes in a musical scale. This term is commonly used in music theory to describe the relationship between two pitches that have a frequency ratio of 2:1. In other words, when a sound wave is played at an octave higher or lower than the fundamental pitch, it creates a harmonic effect.

Explanation
Spectrum graphs are used to describe a complex wave because they display the various frequencies present in the wave. Unlike linear or simple harmonic graphs, which only show the amplitude and time relationship of a wave, spectrum graphs provide a visual representation of the different frequencies and their respective amplitudes within a complex wave. Periodic graphs, on the other hand, represent waves that repeat at regular intervals, which may not be the case for a complex wave. Therefore, the correct answer is spectrum.

Explanation
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Explanation
A complex tone refers to a sound that consists of multiple pure tones of different frequencies and amplitudes. Unlike a pure tone, which has a single frequency, a complex tone is made up of a combination of frequencies, resulting in a more intricate and rich sound. This can be observed in various musical instruments or sounds in nature, where multiple harmonics combine to create a complex tone.

Explanation
Elasticity is not a condition necessary for sound to occur. Sound can be produced without the presence of elasticity in the medium. Elasticity refers to the ability of a material to deform and then return to its original shape when a force is applied. While elasticity can affect the transmission and propagation of sound, it is not a fundamental requirement for sound to be produced. Sound can still occur in non-elastic materials, such as gases or liquids.

Explanation
Sinusoidal motion and simple harmonic motion (SHM) are interchangeable terms that describe the same type of motion. In both cases, an object oscillates back and forth around a stable equilibrium position, following a sinusoidal pattern. The motion is characterized by a constant period and amplitude, and is governed by a linear restoring force that is proportional to the displacement from the equilibrium position. Therefore, SHM is another name for sinusoidal motion.