Age and Sex Differences in Pure-Tone Thresholds

Abstract

In recent years there has been an increased emphasis on medicolegal problems involving the assessment of hearing loss due to noise exposure. One of the attendant difficulties, however, has been the problem of separating the factors of noise exposure and of age as contributors to hearing disabilities. The present study was performed to determine the normal thresholds of hearing for pure tones for an age-stratified sample of subjects drawn from a population exposed to minimal levels of industrial noise. Audiometric measurements from 250 to 8000 cps were made on a total of 500 subjects divided into four age groups: 18 to 24, 26 to 32, 34 to 40, and 43 to 49 years, inclusive. The results of this study indicate that, in general, only minor differences (less than 5 db) exist between the average thresholds of right and left ears, but that women have more sensitive hearing than men and show less intersubject variability. This sex difference is independent of age and is more marked at the higher frequencies. For both men and women, there is a decrease in hearing sensitivity with increasing age and a progressive spreading of the loss from the higher to the lower frequencies. Men are more affected than women, with the hearing loss occurring at an earlier age and producing a greater degree of auditory impairment. The threshold curves of the present study are considered to yield a more valid estimate of the “pure” effects of age on hearing than previously available. It is recommended that future audiometric standards be specified independently for men and for women according to particular age levels.