Abstract

Background Auditory steady-state responses (ASSRs) provide an objective method for estimating hearing thresholds in individuals unable to provide behavioural responses. Bone conduction (BC) testing is required to differentiate conductive from sensorineural hearing loss. Accurate BC ASSR threshold estimation relies on “correction” factors, which are not yet well established. This meta-analysis evaluated the reliability of BC ASSR thresholds to estimate hearing thresholds at 500, 1000, 2000 and 4000 Hz.

Methods A systematic search of PubMed, the Cochrane Library, and Embase was conducted to identify studies involving normal-hearing (NH) and hearing-impaired (HI) participants of all ages. Outcomes were (1) the difference between ASSR behavioural and ASSR thresholds, and (2) ASSR thresholds. The risk of bias was evaluated using the Newcastle-Ottawa Scale. The mean and 95% confidence intervals (CI) were calculated for the thresholds at the four frequencies. The certainty of the evidence was assessed using GRADE approach.

Results Of records identified, 11 records met the inclusion criteria, yielding a total of 27 studies. Sample sizes ranged from 60 to 249 participants across frequencies and age groups. The quality of records ranged from low to high. Data were synthesised using random-effects models due to heterogeneity. In NH adults, the mean differences (±95% CI) between BC ASSR thresholds and behavioural thresholds were 17.0 (±4.8), 15.5 (±6.0), 13.4 (±3.3), and 12.1 (±4.1) dB at 500, 1000, 2000, and 4000 Hz, respectively. In NH infants, mean (±95% CI) BC ASSR thresholds were 17.2 (±2.2), 10.5 (±3.6), 26.4 (±2.7), and 19.9 (±4.0) dB HL at the same frequencies. The certainty of the evidence was very low.

Conclusions BC ASSR can be a reliable method for estimating BC thresholds. However, age and frequency significantly impact BC ASSR thresholds, highlighting the need to develop of “correction” factors to accurately predict BC behavioural thresholds.

Registration PROSPERO CRD42023422150.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

E.P. is supported by the NIHR Manchester Biomedical Research Centre (NIHR203308).

Author Declarations

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This study was a meta-analysis based on data extracted from previous studies.

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Data Availability

All data generated or analyses during this study are included in this published article and its Supplementary Table S5.

Abbreviations/GlossaryACair-conduction thresholdAMEIActive middle ear implantAMamplitude modulationASSRauditory steady-state responseBCbone-conduction thresholdCT2circular T2 testHIhearing-impaired participantDPOAEdistortion-product otoacoustic emissionsHT2Hotelling T2NHnormal-hearing participantMSCmagnitude squared coherenceNOSNewcastle-Ottawa ScalePC2phase coherence squaredPCApost-conceptional agePICOPopulation, Interventions, Comparators and OutcomesSNHLsensorineural hearing lossTEOAEtransient evoked otoacoustic emission.