Sound localization of bilateral implanted CI-patients depending on the duration of bilateral hearing experience
23 April 2019 (online)
A hearing loss decreases the speech perception and the sound localization abilities. Because of the microphone position behind the ear CI-patient can't use the directional filter-function of the ear concha. This study examined the correlation of bilateral hearing experience and the sound localization abilities of CI-patients.
11 bilateral CI-implanted test persons with a mean age of 52,3 (± 14) years were included in this study. The average bilateral hearing experience with CI was 6,2 years. The localization testing was performed in an isolated room without reverberation. 14 test-angles between ± 60 ° in the front and in the backfield where tested. As acoustic stimulus a pulsed „white noise“ was used. The test person's task was to show the perceived sound direction by showing it on a LED-band. In addition to this the test-persons had to sow whether they perceived the noise from the front or the back by turning a switch to the front or the back.
In the front/back localization we found a mean error of 42,86%. The mean angle error was at 13,2 °. We didn't find any correlation between the duration of binaural hearing and the front/back error (r = 0,24, p = 0,48) and no correlation between the binaural hearing experience and the mean angle error (r = 0,37, p = 0,27).
The localization of acoustic signals is a huge challenge for all CI-patients no matter how long the experience with binaural hearing with CI is. An improvement of the sound-localization algorithms of the CI-sound processors would be a benefit for all CI-patients.