Hearing aid noise suppression and working memory function

Abstract

Objective: Research findings concerning the relation between benefit from hearing aid (HA) noise suppression and working memory function are inconsistent. The current study thus investigated the effects of three noise suppression algorithms on auditory working memory and the relation with reading span. Design: Using a computer simulation of bilaterally fitted HAs, four settings were tested: (1) unprocessed, (2) directional microphones, (3) single-channel noise reduction, and (4) binaural coherence-based noise reduction. Settings 2–4 were matched in terms of the speech-weighted signal-to-noise ratio (SNR) improvement. Auditory working memory was assessed at +6 dB SNR using listening span and N-back paradigms. Study sample: Twenty experienced HA users aged 55–80 years with large differences in reading span. Results: For the listening span measurements, there was an influence of HA setting on sentence-final word recognition and recall, with the directional microphones leading to ∼6% better performance than the single-channel noise reduction. For the N-back measurements, there was substantial test-retest variability and no influence of HA setting. No interactions with reading span were found. Conclusion: HA noise suppression may affect the recognition and recall of speech at positive SNRs, irrespective of individual reading span. Future work should improve the reliability of the auditory working memory measurements.

Key Words:

• Hearing aids
• noise reduction
• cognition
• working memory
• individual differences

Acknowledgements

Parts of this study were presented at the 2017 Annual Meeting of the German Audiological Society, Aalen, Germany, Feb. 22–25. We thank Matthias Vormann (Hörzentrum GmbH) and Giso Grimm (HörTech gGmbH) for their help with the test setup.

Declaration of interest: This research was co-funded by Sivantos GmbH, Germany. Author RLF is an employee of that company. Otherwise, there are no conflicts of interest to declare.

This work was supported by the German Research Foundation [grant DFG Cluster of Excellence “Hearing4all” EXC 1077/1] and by Sivantos GmbH, Germany.

Notes

 1. In the study of Ng et al. (2015), no effect of in- or excluding final-sentence word repetition on final-sentence word recall was found.