Assessing the effects of hearing aid provision using an audio-visual ‘online’ measure of speech-in-noise processing
Julia Habicht, Birger Kollmeier and Tobias Neher
Medical Physics and Cluster of Excellence “Hearing4all”, Oldenburg University, Germany
Objective: To assess the effects of noise reduction (NR) and high-frequency audibility on how quickly a participant can grasp the meaning of sentence-in-noise stimuli (the ‘processing time’) using an audio-visual test paradigm. To also assess the effects of linguistic complexity and hearing aid (HA) experience.
Design: Repeated-measures design with HA experience as between-subject factor. HA conditions included clinical linear amplification (‘NAL-R’), NAL-R with single-microphone NR, and linear amplification ensuring a sensation level of ≥15 dB for the speech stimuli up to at least 4 kHz for each individual listener.
Study Sample: 30 elderly hearing-impaired participants, 15 of whom were habitual HA users (‘HA’ group) while the others had no experience with amplified sound (‘noHA’ group). Groups were matched in terms of age, hearing loss, and working memory capacity.
Results: Processing time was negatively affected by NR under conditions of low linguistic complexity. Consistent with previous findings, processing time increased with linguistic complexity and was also poorer for the noHA group.
Conclusions: Single-microphone NR can interfere with elderly HA users’ ability to comprehend sentences in background noise. Follow-up research should systematically investigate the seemingly positive effect of HA experience on the ability to process speech in complex environments quickly.