Abstract
Objective: To assess the American Medical Association (AMA) guide to the evaluation of binaural hearing impairment (BHI) as a procedure for estimating severity of hearing loss from audiograms. Design: The BHIs of Australian war veterans were calculated from their hearing threshold levels (HTLs) and compared with their scores on a hearing questionnaire, the hearing measurement scale (HMS). Study sample: The HTLs of 282 Australian war veterans were measured at frequencies from 0.25 to 8 kHz and scores on the HMS were obtained from 154 of those veterans. Results: No grounds could be found for altering the frequencies included in the average HTL or the high fence of 92 dB HL used in calculating the monaural hearing impairments (MHIs) of the veterans, and no grounds could be found for altering the ratio of 5:1 used in determining the BHI from the MHIs of the better and worse ears. However, agreement between HMS score and BHI was improved by reducing the low fence used in calculating MHI from 25 to 15 dB HL. Conclusion: A modified version of BHI provided an improved procedure for estimating severity of hearing loss from audiograms but would not be suitable for compensation purposes.
Acknowledgements
Appreciation is expressed to colleagues at the National Acoustic Laboratories for their support and encouragement in relation to this project. Thanks are also due to the reviewers of this article, whose comments resulted in many improvements.
Declaration of interest: The author reports no conflicts of interest. The author alone is responsible for the content and writing of this paper.