The Challenge of Listening in Noise in Cochlear Implant Users

Despite major advances in cochlear implant (CI) technology, speech perception in background noise remains a significant challenge for cochlear implant (CI) users, especially when the noise and the target are not spatially separated. Specifically, CI users have shown to require a signal-to-noise ratio (SNR) that is 10-25 dB higher than that of their hearing peers in order to achieve similar performance, placing them at a significant disadvantage in many real-life listening situations. The talk will focus on possible `top-down` listening strategies, such as, selective attention and the ability to follow the characteristics of the speaker in background noise that are known to assist in the recognition of speech in noise and the evidence (or lack of it) in the listening process of CI users. Thus far, the difficulty of listening in noise has been addressed primarily via means of technology, focusing on `bottom-up` processing` which led to limited outcomes. The present talk will discuss the possibility that enhanced performance and efficient use of `bottom-up` cues depend on active involvement of the brain via auditory training. This will be done within the theoretical framework of auditory perceptual learning. Improvement of speech perception in noise of CI users following multisession training in comparison to data of normal hearing participants will be presented while noting the characteristics of auditory learning. The influence of background factors such as chronological age (children, adults, older adults), age of implantation (early versus late implanted in prelingual) and cognitive abilities will be demonstrated and the importance of training conditions will be discussed. Teasing out difficulties in specific listening strategies that CI users have in noise and demonstrating the significant improvements following auditory training may have important clinical implications in addressing one of the important challenges that CI users are still facing.