Listening through hearing aids affects spatial perception and speech intelligibility in normal-hearing listeners

Abstract

Cubick and Dau [(2016). Acta Acust. Acust. 102, 547–557] showed that speech reception thresholds (SRTs) in noise, obtained with normal-hearing listeners, were significantly higher with hearing aids (HAs) than without. Some listeners reported a change in their spatial perception of the stimuli due to the HA processing, with auditory images often being broader and closer to the head or even internalized. The current study investigated whether worse speech intelligibility with HAs might be explained by distorted spatial perception and the resulting reduced ability to spatially segregate the target speech from the interferers. SRTs were measured in normal-hearing listeners with or without HAs in the presence of three interfering talkers or speech-shaped noises. Furthermore, listeners were asked to sketch their spatial perception of the acoustic scene. Consistent with the previous study, SRTs increased with HAs. Spatial release from masking was lower with HAs than without. The effects were similar for noise and speech maskers and appeared to be accounted for by changes to energetic masking. This interpretation was supported by results from a binaural speech intelligibility model. Even though the sketches indicated a change of spatial perception with HAs, no direct link between spatial perception and segregation of talkers could be shown.

Speech intelligibility with various head-related transfer functions: A computational modeling approach

“…They found small but significant effects on speech intelligibility across seven HRTFs from the LISTEN database when using a target talker at 0° and two interfering speech sources at ±90°. Cubick et al (2018) measured speech intelligibility in normal-hearing listeners with and without hearing aids. They showed that hearing aids vary the HRTF as well as reduce the spatial benefit.…”

“…However, they did not include head-movements in the headphone condition but did in the loudspeaker condition, rendering direct comparison problematic. Cubick et al (2018) investigated the effect of the microphone placement in hearing aids on speech intelligibility, which affects the HRTF, and showed a reduced spatial benefit in normal-hearing listeners with hearing aids in comparison to a condition without hearing aids. While these studies do suggest an effect of the HRTF on speech intelligibility, no studies have examined this effect in a direct and controlled way.…”

Measuring access to high-modulation-rate envelope speech cues in clinically fitted auditory prostheses

“…In doing so, it is possible to identify areas where the technical design of the prosthesis, rather than the perceptual limitations of the participant, affects performance. For example, in a speech-intelligibility task, NH listeners were assessed either wearing HAs or unaided (Cubick and Dau, 2016;Cubick et al, 2018). The wearing of high-fidelity HAs appeared to show little or no disadvantage in a co-located masker condition but produced worse performance in a separated masker condition (Cubick et al, 2018) when compared to unaided listening.…”

Impoverished auditory cues fail to engage brain networks controlling spatial selective attention

“…When only isolated or impoverished spatial cues are present, auditory localization performance degrades 45 and the natural perception of external auditory objects may even collapse into the listener's head 46 (Baumgartner et al, 2017;Callan et al, 2013;Cubick et al, 2018;Hartmann and Wittenberg, 1996). 47…”

“…Nevertheless, degraded or isolated ITDs and IIDs still create a strong sense of lateralization within the 48 head; moreover, even highly impoverished spatial cues can be used to achieve spatial release from 49 speech-on-speech masking, behaviorally (Cubick et . More importantly, it is a puzzle as to why realistic and degraded spatial 54 cues yield at best small behavioral differences in masking release even though spatial perception is clearly 55 degraded when cues are impoverished (e.g., Cubick et al, 2018). 56…”