Asymmetric sensorineural hearing thresholds in the non-noise-exposed UK population: a retrospective analysis

To estimate the distribution of inter-aural sensorineural hearing threshold level differences in the non-noise-exposed adult population of the UK.

A two-stage population study carried out in 1979-1986, initially by postal questionnaire, followed up in a proportion of participants by clinical and audiological examination.

Volunteers (n = 48 313) initially selected at random from the electoral registers of four cities, subsequently selected at random from questionnaire respondents stratified by answers to questions about hearing.

Inter-aural hearing threshold level differences measured audiometrically, as a function of age and gender.

Tables of inter-aural threshold level differences provided as a resource with potential medicolegal, clinical and research applications. Based on the average of the frequencies 0.5, 1, 2 and 4 kHz, approximately 1% of the general UK population aged 18-80 years have an asymmetry of 15 dB or more. The prevalence is greater in older than in younger people.

Inter-aural threshold differences greater than attributable to measurement error are not uncommon in the adult population, even after screening for conductive hearing loss and substantial noise exposure. They are typically of unknown origin.