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  • Peer-reviewed study

Spatio-temporal integration of speech reflections in hearing-impaired listeners

From https://assistivelisteningknowledgebase.org/evidence/rennies-2022/ · record checked 9 October 2026

  • Rennies J, Warzybok A, Kollmeier B, Brand T
  • Trends in Hearing 26:23312165221143901

Independent (Fraunhofer Institute for Digital Media Technology IDMT and University of Oldenburg, Cluster of Excellence Hearing4all; funded by the German Research Foundation (DFG, SFB 1330) and the Klaus Tschira Foundation; the authors declare no conflicts of interest)

Summary

Measured how well older listeners with hearing loss understand speech in noise when it arrives with one or more delayed copies of itself, up to 200 ms late, compared with young normal-hearing listeners tested earlier.

Key findings

  • 14 native German speakers aged 45 to 84, most over 70, with mild to moderate sensorineural hearing loss, repeated sentences in speech-shaped noise over headphones, with individual linear amplification (NAL-RP) to restore audibility; their results were compared with a group of normal-hearing listeners aged 18 to 31 from the authors' earlier study.
  • With one delayed copy as loud as the direct speech, thresholds worsened as the delay grew from 10 to 200 ms. At 200 ms, the speech-to-noise ratio needed rose by 6.5 dB on average for the listeners with hearing loss, against 3.4 dB for the normal-hearing group; some listeners needed a positive speech-to-noise ratio (up to +8 dB) to understand half the words.
  • When the 200 ms copy was much louder than the direct sound (2.5 times its amplitude, the largest ratio tested), every listener's threshold returned close to their result with no copy at all; the copy hurt most when the two were about equally loud.
  • With several delayed copies spread over 200 ms, many listeners could not reach 50% understanding even at +20 dB: for seven copies, no threshold could be measured for 8 of the 14.
  • The authors conclude that listeners with hearing loss were generally less able than normal-hearing listeners to ignore the earlier sound when the useful speech came later, and that individual results were predicted better by speech-in-noise performance in simple conditions than by the audiogram.

Limits

Artificial room responses over headphones in a laboratory, with copies delayed by no more than 200 ms; no hearing aids, assistive listening stream or real room. Small group of 14, compared with a normal-hearing group from an earlier study that was much younger.

Read the original

pmc.ncbi.nlm.nih.gov/articles/PMC9772954

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Cite this source

Rennies J, Warzybok A, Kollmeier B, Brand T. Spatio-temporal integration of speech reflections in hearing-impaired listeners. Trends in Hearing 26:23312165221143901. 19 December 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC9772954/ (accessed 9 October 2026).

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