Some aspects of the physiology of the ear and noise impact

Abstract

The auditory system is not equally sensitive to all frequencies and operates nominally over a range of 20 to 20.000 Hz. This is reflected in the minimum audibility curve, what can be largely attributed to the response characteristics of the outer and middle ear. These characteristics – anatomical and functional – of the outer and middle ear will be reviewed, as also their performance in the presence of noise. The contribution of the acoustic reflex measurement to hearing conservation programs will also be reviewed. The inner ear will be discussed with an emphasis on the basic mechanisms involved in the inner ear injury due to noise exposure and the reasons why noise is so damaging to its basal portion.