Unit 3a - Hearing Conservation

Explanation
Photo C demonstrates the correct way to wear your ear plugs. Not having the ear plug inserted correctly will decrease its Noise Reduction Rating and ability to protect your hearing.

Explanation
Yes, you have been overexposed to noise. A noise level of 108dB is considered extremely high, and prolonged exposure to such noise can cause permanent hearing damage. The fact that you have been using the impact wrench for 6 straight hours without any hearing protection increases the risk of overexposure. It is important to always wear appropriate hearing protection in loud environments to prevent long-term damage to your hearing.

Explanation
Yes, you can work for 8 hours in this environment. The noise level is 92dB, but you are wearing ear plugs with a Noise Reduction Rating (NRR) of 23dB. The NRR indicates the amount of noise that the ear plugs can block out. By wearing the ear plugs, the effective noise level that reaches your ears is reduced by 23dB. Therefore, the actual noise level you are exposed to is 69dB (92dB - 23dB). This level is within the acceptable range for prolonged exposure, so you can work for 8 hours without any adverse effects.

Explanation
NIHL can be permanent depending on many factors, such as length of time exposed to the noise, intensity of the noise, and personal factors.

Explanation
Without hearing protection, it is safe to work in a noise level of 90dB for a maximum of 8 consecutive hours. This is because prolonged exposure to high noise levels can cause damage to the ears and lead to hearing loss. Therefore, it is important to limit exposure to loud noises and use hearing protection when necessary.

Explanation
All of the above options indicate that the noise level is too great. If the noise hurts your ears, it suggests that the noise is too loud and can potentially cause damage to your hearing. Similarly, if you have to shout over a short distance to be heard, it indicates that the noise level is too high for normal conversation. Additionally, if you experience difficulty in hearing for a few hours after being exposed to the noise, it implies that the noise level was excessive and affected your hearing temporarily. Therefore, all of these signs collectively suggest that the noise level is too great.

Explanation
The intensity of noise is measured in decibels. Decibels is a unit used to quantify the level of sound or noise. It is a logarithmic scale that measures the ratio of the sound pressure level to a reference level. This scale allows for the measurement of a wide range of sound intensities, from the faintest sounds to extremely loud ones. The higher the decibel level, the louder the noise. Therefore, decibels are the appropriate unit of measurement for noise intensity.

Explanation
The correct answer is 85dB. This is the threshold for what is considered a hazardous noise level. Noise levels above 85dB can cause damage to the hearing if exposed to for long periods of time. It is important to take measures to protect oneself from excessive noise exposure in order to prevent hearing loss.

Explanation
By playing your music loud enough to drown out the noise of the lawn mower, you have increased your risk of NIHL by adding to the sound of the mower.

Music Headphones are never effective as hearing protection.

Explanation
The correct answer is 3 hours because the question asks about the duration of a concrete chipping operation rated at 97 decibels before overexposure occurs. Without hearing protection, prolonged exposure to high decibel levels can lead to hearing damage. The duration of 3 hours indicates that after this time, the individual would be at risk of overexposure and potential hearing damage.