Valzolgher, C. 2, 1 , Farné, A. 2 & Pavani, F. 1, 3, 2
1 Centre for Mind/Brain Sciences (CIMeC), University of Trento
2 IMPACT, Centre de Recherche en Neuroscience Lyon (CRNL), France
3 Department of Psychology and Cognitive Sciences (DiPSCo), University of Trento
Hearing in noise is a major challenge for hearing impaired people. In noisy environments, increased separation between target and noise improves performance and decrease listening effort, a phenomenon defined Spatial Release from Masking (SRM). Research showed limited SRM in individuals with hearing loss, and in hearing participants with one ear plugged. Here we examined if seeing sound sources can enhance SRM in hearing participants (N=18) tested in binaural or monaural listening conditions. Participants were asked to report 5 digits embedded in time-reversed speech, delivered at 3 different signal-to-noise ratios from two loudspeakers. Across blocks, speakers were either close or far, visible or hidden. As expected, overall performance was worse in monaural vs. binaural listening. SRM emerged selectively under binaural listening, whereas separation between the speakers hindered monaural performance (because the target stream moved further towards plugged side, whereas the noise moved towards the hearing side, decreasing SNR). Remarkably, seeing the speakers contrasted this SNR change, at least for the easiest SNR level. This finding suggests that seeing sources may help auditory scene segregation, even when vision is uninformative about the target auditory stream. This multisensory advantage could be exploited when training listening in noise for cochlear implant or hearing-aid users.