Spatial Release From Masking in Children: Effects of Simulated Unilateral Hearing Loss

Abstract

Objectives The purpose of this study was twofold: 1) to determine the effect of an acute simulated unilateral hearing loss on children’s spatial release from masking in two-talker speech and speech-shaped noise, and 2) to develop a procedure to be used in future studies that will assess spatial release from masking in children who have permanent unilateral hearing loss. There were three main predictions. First, spatial release from masking was expected to be larger in two-talker speech than speech-shaped noise. Second, simulated unilateral hearing loss was expected to worsen performance in all listening conditions, but particularly in the spatially separated two-talker speech masker. Third, spatial release from masking was expected to be smaller for children than for adults in the two-talker masker. Design Participants were 12 children (8.7 to 10.9 yrs) and 11 adults (18.5 to 30.4 yrs) with normal bilateral hearing. Thresholds for 50%-correct recognition of Bamford-Kowal-Bench sentences were measured adaptively in continuous two-talker speech or speech-shaped noise. Target sentences were always presented from a loudspeaker at 0° azimuth. The masker stimulus was either co-located with the target or spatially separated to +90° or −90° azimuth. Spatial release from masking was quantified as the difference between thresholds obtained when the target and masker were co-located and thresholds obtained when the masker was presented from +90° or − 90°. Testing was completed both with and without a moderate simulated unilateral hearing loss, created with a foam earplug and supra-aural earmuff. A repeated-measures design was used to compare performance between children and adults, and performance in the no-plug and simulated-unilateral-hearing-loss conditions. Results All listeners benefited from spatial separation of target and masker stimuli on the azimuth plane in the no-plug listening conditions; this benefit was larger in two-talker speech than in speech-shaped noise. In the simulated-unilateral-hearing-loss conditions, a positive spatial release from masking was observed only when the masker was presented ipsilateral to the simulated unilateral hearing loss. In the speech-shaped noise masker, spatial release from masking in the no-plug condition was similar to that obtained when the masker was presented ipsilateral to the simulated unilateral hearing loss. In contrast, in the two-talker speech masker, spatial release from masking in the no-plug condition was much larger than that obtained when the masker was presented ipsilateral to the simulated unilateral hearing loss. When either masker was presented contralateral to the simulated unilateral hearing loss, spatial release from masking was negative. This pattern of results was observed for both children and adults, although children performed more poorly overall. Conclusions Children and adults with normal bilateral hearing experience greater spatial release from masking for a two-talker speech than a speech-shaped noise masker. Testing in a two-talker speec...

Speech recognition in one- and two-talker maskers in school-age children and adults: Development of perceptual masking and glimpsing

“…The smaller age effect for noise maskers than speech maskers has been interpreted as indicating that children experience little or no perceptual masking with noise maskers. This conclusion receives support from the finding that spatial segregation provides marked benefits for speech-in-speech, but only modest benefit for speech-in-noise recognition in children or adults (Corbin et al, 2017;Freyman et al, 2001). Interestingly, infants may experience perceptual masking in both noise and speech-based maskers , suggesting that the ability to perceptually isolate target speech from a noise masker may be learned.…”

Masked Speech Recognition in School-Age Children

“…Children required a more advantageous SNR to achieve the same criterion level of performance as adults in all three masker conditions, but the magnitude of SRM was similar across age. Subsequent studies have confirmed that children benefit from target/masker differences in spatial location in the context of speech-in-speech recognition (e.g., Johnstone and Litovsky, 2006; Cameron et al, 2009; Murphy et al, 2011; Yuen and Yuan, 2014; Corbin et al, 2017). Note, however, that findings from more recent studies indicate that young children experience reduced SRM relative to older children and adults when the target stimuli and/or listening conditions are more challenging (e.g., Cameron et al, 2009; Brown et al, 2010; Yuen and Yuan, 2014; Corbin et al, 2016).…”

Auditory Training for Spatial Hearing Loss: Two Case Reports of the Older Adults Who Wear Hearing Aids

“…The auditory training consisted of 16 sessions where azimuth [e.g., S 0 N +90 ]). One thing to bear in mind in parts 4 and 5, was that the SRM could become negative when the noise masker was presented to the better ear (Corbin et al, 2017). It is because the participant's spatial hearing can be affected by the noise masker presented to the good ear more than the poor ear.…”