Avoiding disconnection: An evaluation of telephone options for cochlear implant users

The primary aim of this study was to evaluate the effect of coupling method on telephone-based speech recognition and perceived listening difficulty in noise for cochlear implant (CI) users. A secondary aim was to evaluate potential impacts of additional processing modifications within coupling conditions, such as activating noise reducing algorithms or muting environmental microphones.

Hochmair-Schulz-Moser sentences were bandpass-filtered (300-3400 Hz) and presented unilaterally either via telephone handset or advanced wireless streaming device in a background of cafeteria babble (signal-to-noise ratio =15 dB). Sentence recognition was scored at the word level and perceived listening difficulty was assessed via visual-analogue scale for each of five test conditions.

Twenty native German-speaking CI users participated.

Repeated measures analysis of variance revealed coupling via advanced streaming significantly improved sentence recognition and reduced listening difficulty, when compared to either telecoil or acoustic coupling configurations. In addition, program modifications further increased benefit within a coupling condition. CI users who exhibited the most difficulty during basic acoustic coupling were most likely to benefit from advanced wireless streaming.

CI users have several options for improving speech recognition and decreasing listening difficulty over the telephone when listening in noisy environments.