Clinical Picture of Occupational Hearing Loss obtained with the Hearing Measurement Scale

The Hearing Measurement Scale is briefly described. It is a questionnaire which has been developed for use among people suffering from occupational hearing loss and its purpose is the assessment of disability in those with sensori­ neural lesions. It is used here to reveal the clinical picture of occupational hearing loss in men employed as drop-forgers. Results from two men are pre­ sented in detail together with their audiograms. It is shown that, despite simi­ larity in terms of audiograms, the two men differ materially in terms of the clinical picture which they present. Two systems of assessment that depend on averages of pure-tone thresholds at 0-5, 1-0 and 2-0 kHz fail to show correctly which of the two men is the worse affected.

Results from the group of drop-forgers show, as would be expected, that the relationship is good between the various audiometric averages, for example, at 0-5, 1-0 and 2-0 kHz; 0-5, 1-0, 2-0 and 3-0 kHz. On the other hand the relation­ ships between these averages and questionnaire scores is incomplete. It is argued on these grounds that pure-tone audiograms are an inadequate basis for the assessment of hearing disorder.

Questionnaire scores are compared among patients attending a hearing-aid clinic and occupational samples of metal dressers (chippers), weavers and drop­ forgers. It is concluded that the clinical picture of occupational hearing loss for drop-forgers is not unusual for people in their sixth decade who have spent at least half of their working lifetimes in high levels of noise. The median clinical picture for these men is of an essentially trivial disorder of hearing. For those at and beyond the 75th centile of scores the picture is more serious.