Assistive listening technology in cochlear implant users in reverberant environments with multiple noise sources

Abstract

Purpose This study aimed to evaluate the contribution of assistive listening technology with wireless connectivity in cochlear implant (CI) users in reverberating and noise situations. Methods Prospective cross-sectional study approved by the Institutional Ethics Committee (CAAE 8 3031418.4.0000.0068). Adolescents and adults CI users with pre- or post-lingual deafness were selected. For bilateral users, each ear was assessed separately. Speech recognition was assessed using recorded lists of disyllabic words presented at 65 dBA at 0° azimuth with and without the Wireless Mini Microphone 2 (Cochlear™) connected to the Nucleus®6 speech processor. Room reverberation was measured as 550 ms. To assess the contribution of the assistive listening device (ALD) in a reverberating environment, speech recognition was assessed in quiet. To assess the contribution of the ALD in reverberation and noise, speech recognition was presented at 0° azimuth along with the noise coming from 8 loudspeakers symmetrically arranged 2 meters away from the center with multi-talker babble noise using signal to noise ratio of +10dB. To avoid learning bias or fatigue, the order of the tests was randomized. Comparison of means was analyzed by t test for paired samples, adopting significance level of p <0.005. Results Seventeen patients with a mean age of 40 years were invited and agreed to participate, with 2 bilateral participants, totaling 19 ears assessed. There was a significant positive contribution from the Mini Mic2 in reverberation, and noise+reverberation (p <0.001). Conclusion ALD was able to improve speech recognition of CI users in both reverberation and noisy situations.