The intervals of the sound waves are greater than one second apart and are characterized by a high-amplitude, very short wave. Inner Ear Cochlea, semicircular canals and auditory nerve. Linear A sound that is a consistently flat response throughout the measured frequency range. The average attenuation value calculated received received in each test frequency. NHCA National Hearing Conservation Association NIHL Noise Induced Hearing Loss due to noise exposure.
All testing is performed in a controlled environment.
Consequently, posted NRR ratings are a qualified example of how the individual products compare with other similar hearing protection products in an uncontrolled noise environment. Test results do not evaluate the product reusability, comfort, adaptability or quality. In the final analysis, the user must make this determination. The visable, outer portion of the ear, which should be enclosed completely by earmuff cups. Presbycusis Type of sensory neural hearing loss due to aging.