Extended high frequency audiometry thresholds in healthy school children

Abstract

ObjectivesExtended high frequency (EHF) audiometry is the recommended method for monitoring oxotoxic hearing loss in children. This study aims to provide high quality reference audiological data for the EHF range in healthy children. MethodsParticipants were 126 healthy schoolchildren between 6 and 14 years of age. All participants were term born with normal birthweight, had not suffered severe neonatal illness and had no history of middle ear disease. ResultsThe averaged mean (SD) hearing threshold for the EHF 9, 10, 11.2, 12.5, 14 and 16 kHz was −0.4 (6.0) dB HL. The lowest mean hearing thresholds were observed at 14 kHz with −4.2 (8.7) dB and at 16 kHz with −6.4 (12.1) dB HL. We found significantly lower thresholds at 16 kHz for children aged 6–9 years (−8.7 dB HL) compared to age 10–14 years (−3.9 db HL), p 0.042. For both age groups the inter-subject variability increased in the highest frequencies. We found no significant differences in mean hearing thresholds between right and left ears at any frequency, and no gender differences in the EHF range. ConclusionOur findings support that decreased hearing sensitivity in the EHF's may start around or even before the age of 10 years. In order to use EHF audiometry for ototoxic monitoring in children, we suggest to establish an international reference standard for hearing levels in children under the age of 18. Specific references for different age groups are needed as hearing in the EHF range appears to gradually deteriorate from an early age. Clinical trial registrationNCT03253614.