ATTENTION DECODING AT THE COCKTAIL PARTY: PRESERVED IN HEARING AID USERS, REDUCED IN COCHLEAR IMPLANT USERS

Understanding a target speaker in multi-talker environments remains a significant challenge for users of hearing aids(HAs) and cochlear implants (CIs). Cortical activity tracks the envelope of speech signals in a way that depends on attention: the cortical tracking is larger for an attended than for an ignored speech stream. Auditory attention decoding based on this neural response may be used for neurofeedback in hearing devices, potentially enhancing speech-in-noise comprehension through reducing background noise. With the present study, we aimed to investigate auditory attention decoding and speech-in-noise understanding in hearing-impaired individuals.
To this end, we collected EEG data from 24 CI users, 29 HA users, and 29 typical hearing (TH) individuals, while they were focusing on one of two competing speakers (one male, one female), in a free-field acoustic environment [1]. All cohorts were age-matched, and both CI and HA users wore their clinically fitted devices during the study, which assured ecological validity. Cortical speech tracking was assessed through linear backward and forward models that related the EEG data to the speech envelope (1-8 Hz).
The HA group exhibited attentional modulation of the cortical speech tracking that was largely comparable to that of the TH group. This suggests that HAs are good candidates for neurosteered hearing technology While CI users also showed successful cortical tracking, their neural segregation of the attended vs. the ignored speech streams was profoundly reduced, posing methodological challenges for the development of neuro-steered CIs.
[1] Jehn et al., bioRxiv https://doi.org/10.64898/2025.12.22.695344.