The Clinical Value of Auditory Steady State Responses

Large numbers of South African mine workers incur noise-induced hearing loss. The prevalence of noise-induced hearing loss is such that its financial implications for the industry are significant. This situation is often further compounded by an exaggeration of their hearing loss by some workers in an attempt to obtain compensation. Questionable cases must be re-assessed, increasing the cost of evaluations and the number of unproductive shifts.The inability to obtain true pure-tone thresholds in unco-operative workers leads to ineffectiveness in and frustration for audiologists and occupational health centres because they are not delivering an accountable service to the mining company and individual workers. The failure to obtain pure-tone thresholds may also lead to deserving workers not receiving compensation, and sudden hearing loss not being diagnosed. Workers unfit for their present occupations can also be further exposed to noise.Current audiological procedures can identifyinstances of exaggerated hearing loss (pseudohypacusis), but do not quantify the extent of exaggeration. Traditional testing techniques require patient co-operation and, hence, are insufficient to resolve cases where patient co-operation is not forthcoming.As a result this study was undertaken to determine the value of auditory steady state responses (ASSRs) as a means of estimating the pure-tone thresholds of noise-exposed workers. ASSRs need no response from the patient, and the electrical responses to the presented sound are measured by means of a real-time statistical analysis of the samples, using a computer, thereby offering real objectivity. The outcomes of this study are discussed in this book.