Objective Treatment options for patients with single-sided deafness (SSD) or asymmetric hearing loss (AHL) are: (Bi)CROS hearing aid, bone conduction implant (BCI) and cochlear implant (CI). Only a CI allows restoration of binaural hearing. The advantages of binaural hearing with CI have been shown in previous studies. Due to their heterogeneity, it is impossible to compare results. Our study is based on a unified testing protocol designed for application in multicenter studies and pooling data from monocentric studies.
Methods Outcome measures are assessed pre- and postoperatively 1, 3, 6 and 12 months after activation of CI. Twelve SSD and AHL patients participate in the study. All patients completed the 6M examinations. Amongst others, speech reception thresholds (SRT) unaided and CI-aided are measured for two different noises (Olnoise and 2-talker babble noise (TTBN)) in 5 different presentation conditions (SSSDNAH, S0NSSD, S0N0, S0NAH, SAHNSSD). Thresholds are obtained using a modified Oldenburg sentence test (OLSA).
Results Six months after CI activation, all patients performed much better with CI than preoperatively unaided: SRT improvements in TTBN range from 2.4 to 12.0 dB in the SSSDNAH condition (head shadow effect), from 2.9 to 5.3 dB in S0N0 (summation effect), and from 1.2 to 9.0 dB in S0NSSD (squelch effect). The use of the CI was favorable in all tested presentation conditions, even in SAHNSSD, for which SRT improved by 0.5 to 10.6 dB.
Conclusion Our results show benefits in speech comprehension in noise with CI, for both noise types and in all 5 presentation conditions revealing the presence of head shadow as well as binaural summation and squelch effects.
MED-EL Deutschland GmbH
