About the impact of hearing impairment on processing effort and the benefit of hearing aid signal processing

Speech perception in adverse listening situations can be exhausting. Hearing loss particularly affects processing demands, which requires increased processing effort for successful speech perception in background noise. Signal processing in hearing aids and noise reduction (NR) schemes aim to counteract the effect of noise and reduce the effort required for speech recognition in adverse listening situations.

This talk outlines some studies investigating the impact of hearing loss on processing effort and the benefit of a NR scheme on speech recognition and effort. The influence of hearing loss and NR processing on effort was evaluated by measuring the Peak Pupil Dilation (PPD) of listeners while performing a speech recognition task.

Speech recognition performances and PPDs were measured in different listening situations varying in SNR and/or speech intelligibility. A significant interaction effect between SNR and hearing-status on effort was found. Moreover, a benefit of the NR scheme on effort was demonstrated for hearing-impaired listeners at positive SNRs, i.e. for listening situations where speech recognition was at ceiling performance.

The results emphasized the relevance of measuring processing effort in situations where the traditional speech reception measures fail due to ceiling effects.