Effects of Monaural Asymmetry and Target–Masker Similarity on Binaural Advantage in Children and Adults With Normal Hearing

Abstract

Purpose For colocated targets and maskers, binaural listening typically offers a small but significant advantage over monaural listening. This study investigated how monaural asymmetry and target–masker similarity may limit binaural advantage in adults and children. Method Ten Mandarin-speaking Chinese adults (aged 22–27 years) and 12 children (aged 7–14 years) with normal hearing participated in the study. Monaural and binaural speech recognition thresholds (SRTs) were adaptively measured for colocated competing speech. The target–masker sex was the same or different. Performance was measured using headphones for three listening conditions: left ear, right ear, and both ears. Binaural advantage was calculated relative to the poorer or better ear. Results Mean SRTs were significantly lower for adults than children. When the target–masker sex was the same, SRTs were significantly lower with the better ear than with the poorer ear or both ears ( p < .05). When the target–masker sex was different, SRTs were significantly lower with the better ear or both ears than with the poorer ear ( p < .05). Children and adults similarly benefitted from target–masker sex differences. Substantial monaural asymmetry was observed, but the effects of asymmetry on binaural advantage were similar between adults and children. Monaural asymmetry was significantly correlated with binaural advantage relative to the poorer ear ( p = .004), but not to the better ear ( p = .056). Conclusions Binaural listening may offer little advantage (or even a disadvantage) over monaural listening with the better ear, especially when competing talkers have similar vocal characteristics. Monaural asymmetry appears to limit binaural advantage in listeners with normal hearing, similar to observations in listeners with hearing impairment. While language development may limit perception of competing speech, it does not appear to limit the effects of monaural asymmetry or target–masker sex on binaural advantage.

Cochlear Implant Facilitates the Use of Talker Sex and Spatial Cues to Segregate Competing Speech in Unilaterally Deaf Listeners

“…It is not surprising that the hearing status in the nonimplanted ear limited segregation of competing speech for the Baseline condition. Interestingly, Liu et al (2020) found significant performance asymmetry across ears for SRTs in NH children when target and masker speech were colocated and no talker sex cues were available. They found no binaural benefit over the better-ear alone, similar to observations with the present unilaterally deaf CI users.…”

“…Recognition of target speech in the presence of masker speech was measured using the matrix-style test materials from the Closed-Set Mandarin Speech corpus (Tao et al 2017), which has been used in several studies by Fu and colleagues (Tao et al 2018; Liu et al 2019; Chen et al 2020; Liu et al 2020). The stimuli consisted of 5 categories (Name, Verb, Number, Color, and Object), each with 10 words.…”