Hearing aid noise suppression and working memory function

摘要

Research findings concerning the relation between outcome from hearing aid (HA) noise suppression and working memory function are unclear. The current study thus investigated the effects of three noise suppression algorithms on auditory working memory as well as the relation with reading span. 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 a listening span and an -back paradigm. Twenty experienced HA users aged 55-80 yr with large differences in reading span took part. For the listening span measurements, there was an influence of HA setting on final word recognition and recall, with the directional microphone setting leading to approx. 6% better performance than the single-channel noise reduction setting. For the -back measurements, there was substantial test-retest variability and no influence of HA setting. No interactions with reading span were found. These results imply that HA noise suppression can affect the recognition and recall of speech at positive SNRs, irrespective of individual reading span.