Gender differences in binaural speech-evoked auditory brainstem response: are they clinically significant?

Bahram Jalaei,Mohd Hafiz Afifi Mohd Azmi,Mohd Normani Zakaria

doi:10.1016/j.bjorl.2018.04.005

Abstract

IntroductionBinaurally evoked auditory evoked potentials have good diagnostic values when testing subjects with central auditory deficits. The literature on speech-evoked auditory brainstem response evoked by binaural stimulation is in fact limited. Gender disparities in speech-evoked auditory brainstem response results have been consistently noted but the magnitude of gender difference has not been reported. ObjectiveThe present study aimed to compare the magnitude of gender difference in speech-evoked auditory brainstem response results between monaural and binaural stimulations. MethodsA total of 34 healthy Asian adults aged 19–30 years participated in this comparative study. Eighteen of them were females (mean age=23.6±2.3 years) and the remaining sixteen were males (mean age=22.0±2.3 years). For each subject, speech-evoked auditory brainstem response was recorded with the synthesized syllable /da/ presented monaurally and binaurally. ResultsWhile latencies were not affected (p>0.05), the binaural stimulation produced statistically higher speech-evoked auditory brainstem response amplitudes than the monaural stimulation (p<0.05). As revealed by large effect sizes (d>0.80), substantive gender differences were noted in most of speech-evoked auditory brainstem response peaks for both stimulation modes. ConclusionThe magnitude of gender difference between the two stimulation modes revealed some distinct patterns. Based on these clinically significant results, gender-specific normative data are highly recommended when using speech-evoked auditory brainstem response for clinical and future applications. The preliminary normative data provided in the present study can serve as the reference for future studies on this test among Asian adults.

Highlights

Auditory brainstem response (ABR) is a well-known objective test for assessing the neural function within the auditory brainstem region
In terms of speech-ABR amplitudes, for each gender, significantly higher amplitudes were noted in the binaural stimulation compared to the monaural stimulation for all speech-ABR peaks (p < 0.05) (Fig. 4)
Recall that the main aim of the present study was to compare the magnitude of gender disparity in the speech-ABR results between monaural and binaural stimulations

Summary

Introduction

Auditory brainstem response (ABR) is a well-known objective test for assessing the neural function within the auditory brainstem region. There is a growing attention to study ABR when evoked by complex stimuli.2---6. By utilizing complex stimuli such as speech sounds to record ABR, information on how speech acoustic features are encoded at the subcortical level can be obtained in an objective manner.[2] This would promote the potential use of ABR in studying subjects with auditory processing deficits involving the brainstem region.[4] In many studies, a consonant---vowel syllable such as /da/ has been used to record speech-evoked ABR (speechABR).5---10 the speech-ABR typically consists of seven peaks that faithfully describe the acoustic elements of the syllable /da/. Abnormal speech-ABR results have been reported in subjects with compromised subcortical functions including those with auditory processing disorders, learning disabilities, attention deficit hyperactivity disorder and autism spectrum disorders.7---10

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