Perception of consonants in reverberation and noise by adults fitted with bimodal devices

The purpose of this study was to evaluate the contribution of a contralateral hearing aid to the perception of consonants, in terms of voicing, manner, and place-of-articulation cues in reverberation and noise by adult cochlear implantees aided by bimodal fittings.

Eight postlingually deafened adult cochlear implant (CI) listeners with a fully inserted CI in 1 ear and low-frequency hearing in the other ear were tested on consonant perception. They were presented with consonant stimuli processed in the following experimental conditions: 1 quiet condition, 2 different reverberation times (0.3 s and 1.0 s), and the combination of 2 reverberation times with a single signal-to-noise ratio (5 dB).

Consonant perception improved significantly when listening in combination with a contralateral hearing aid as opposed to listening with a CI alone in 0.3 s and 1.0 s of reverberation. Significantly higher scores were also noted when noise was added to 0.3 s of reverberation.

A considerable benefit was noted from the additional acoustic information in conditions of reverberation and reverberation plus noise. The bimodal benefit observed was more pronounced for voicing and manner of articulation than for place of articulation.