A critical review of King-Kopetzky syndrome: hearing difficulties, but normal hearing?

King-Kopetzky syndrome (KKS) is the condition in which an individual complains of having difficulties understanding speech in background noise but has normal hearing thresholds on pure tone audiometry. KKS is a relatively common condition and recognized as a clinically unique group in the audiological or ENT clinics (about 1-10%). The absence of any abnormal audiometric findings to explain their hearing difficulties leaves the clinicians or audiologists with a diagnostic dilemma and presents difficulties in dealing with the patients. Consequently, in the past they have often simply been reassured or even been recognized as non-organic hearing loss or psychological or neurotic. With developments in audiological technology and in hearing physiology, comprehensive test protocols have been developed to identify the possible pathogenesis underlying patients with KKS. The purpose of this paper is to review the advances in the development of sensitized and objective assessments of subclinical auditory dysfunction in patients with KKS. This should be valuable to provide guidelines on the pathogenesis and consequently lead towards a better understanding of KKS. Appropriate approaches to the process of rehabilitative management of patients with King-Kopetzky syndrome are also discussed.