EFFECT OF PROLONGED EXPOSURE TO INTENSE NOISE ON HEARING ACUITY

INTRODUCTION  HEARING impairment resulting from exposure to industrial noise was appreciated as far back as 1831 by Fosbroke.¹ Since then this condition has been variously termed occupational deafness, industrial deafness, or acoustic trauma. It has been incontestably demonstrated in certain employees engaged as boilermakers, weavers, and chippers and in persons exposed to small-arms gunfire.Even prior to the development of the audiometer many otologists recognized the general characteristics of occupational deafness, particularly the loss in high-tone acuity as demonstrated by the subject's inability to hear the whispered voice. Among these early investigators were Gottstein and Kayser,² Lake,³ Wittmaack,⁴ Röpke,⁵ Barr,⁶ and Laurens.⁷ With the advent of the audiometer and the tremendous increase in industrial noise, considerable effort has been made to determine the intensity and type of impairing noise and criteria significant in the production of acoustic trauma.During the past decade the