Predicting children’s real-ear-to-coupler differences based on tympanometric data

Abstract

Objective

Paediatric hearing-aid verification relies on measures of output obtained from the ear canal or in a coupler with the child’s real-ear-to-coupler difference (RECD). Measured RECD cannot always be completed in children, leading to fitting inaccuracies. Audiologists often have tympanometry data that characterises the child’s ear-canal acoustics. The goal of this study was to determine if tympanometry can be used to improve predictions of measured RECD.

Design

A retrospective analysis of RECD and admittance, tympanometric peak pressure, and equivalent ear-canal volume from 226 Hz tympanometry collected as part of a longitudinal study of children with hearing loss were modelled with Bayesian hierarchical regression.

Study sample

Two-hundred sixty-six children with mild-to-severe hearing loss contributed data.

Results

Age-based average RECD models were within 3 dB of measured RECD values in 54% of cases with normal middle ear status and 50.6% of cases with abnormal middle ear status. Immittance-predicted RECD were within 3 dB in 69.6% of cases with normal middle ear status and 74.4% of cases with abnormal middle ear status.

Conclusion

Immittance-predicted RECD was more accurate than age-based average RECD, particularly in children with abnormal middle ear status. The findings suggest that 226 Hz tympanometry could be used clinically to improve predictions of measured RECD when it cannot be measured.

Keywords:

• Paediatric
• hearing-aid
• acoustics
• real-ear-to-coupler difference
• verification
• hearing loss

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Research reported in this publication was entirely supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under award numbers R01 DC013591 and R01 DC018330. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.