Influence of reverberation on localization abilities and speech performance in noisy environment for cochlear implant users with single sided deafness

The binaural processing of auditory signals is essential for speech intelligibility in noise and the localization of acoustic signals. Cochlear implants (CI) allow hearing impaired with single sided deafness (SSD) a binaural hearing. In this study the influence of reverberation on the speech understanding in noise and the localization performance of SSD subjects and normal hearings (NH) was analyzed. Five experienced SSD subjects (ᴓ Age: 50 years) and 21 NH (ᴓ Age: 28 years) participated in the study. The tests are performed in an anechoic chamber in a free field condition and with reverberation (room simulation of an auditorium). The mean localization ability was measured for broadband pulsed noise stimuli in the frontal horizontal plane for angles between ± 60°. The speech reception thresholds (SRT) were tested with four time-wise decorrelated noise sources (amplitude modulated white noise) and frontal speech presentation. The median angular error for SSD subjects in free field was 12.1° and for NH 1.8°. There was a wide variation in the localization abilities for the CI subjects. When adding reverberation the speech performance of the SSD subjects decreased significantly from -11.8 dB SNR in free field to -4.8 dB SNR (for NH: -14.0 dB SNR in free field condition and -10.3 in reverberation condition). All SSD subjects showed an appropriate localization performance for daily life. The localization and the speech performance aggravated in the presence of reverberation, especially for the SSD user.

Deutsche Forschungsgesellschaft (BA 2085/6-1 zum Thema „Untersuchung binauraler Hörleistungen bei bilateraler Cochlea-Implantat Versorgung in realistischen Raum- und Störschallsituationen.“)

Poster-PDF A-1884.PDF

Publication History

Article published online:
10 June 2020