Simplified cochlear frequency selectivity assessment in normal-hearing and hearing-impaired listeners

Abstract

Objective

The ear’s spectral resolution or frequency selectivity (FS) is a fundamental aspect of hearing but is not routinely measured in clinical practice. This study evaluated a simplified FS testing procedure for clinical use by replacing the time-consuming two-interval forced choice (2IFC) method with method of limits (MOL) carried out using a custom-made software and consumer-grade equipment.

Design and study sample

Study 1 compared the FS measure obtained with MOL and 2IFC procedure at two centre frequencies (CFs) (1 and 4 kHz) in 21 normal-hearing listeners. Study 2 determined the FS measure using MOL at five CFs (0.5–8 kHz) in 32 normal-hearing and nine sensorineural hearing loss listeners and compared them with their thresholds in quiet.

Results

FS measurements with MOL and 2IFC methods were highly correlated and had statistically comparable intra-subject test-retest reliability. FS measures determined with MOL were reduced in the hearing-impaired compared to normal-hearing listeners at the CF corresponding to their hearing loss. Linear regression analysis showed significant relationship between FS deterioration and quiet threshold loss (p < 0.0001, R² = 0.56).

Conclusions

The simplified and affordable FS testing method can be used alongside audiometry to provide additional information about the cochlear function.

Keywords:

• Frequency selectivity test
• notched-noise masker
• hearing loss
• low-cost hearing test
• adult hearing screening
• pure tone audiometry

Acknowledgement

The authors thank Dr Hong Yet Hoi for aiding in study design. Prof. Geoff Hammond (University of Western Australia) provided the original LabVIEW codes for the 2IFC task.

Ethical approval

Ethics approval was obtained from University of Malaya Medical Centre-Medical Research Ethic Committee (UMMC-MREC, ID No: 2020311-8375) and all volunteers provided informed consent.

Disclosure statement

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

Additional information

Funding

This work was supported by University of Malaya Faculty Research Grant (GPF005A-2020).