Benefits of bimodal stimulation for adults with a cochlear implant

Many clinics now recommend the trial of a hearing aid for the contralateral ear for adults with a cochlear implant (bimodal stimulation). This paper builds on earlier research and examines the utility of providing a hearing aid in the contralateral ear for adult cochlear implant users. Eight adults with a cochlear implant were fitted with an Oticon SUMO XP hearing aid. Performance was evaluated in terms of speech perception in quiet and noise (front, left and right), localisation performance (front, left and right) and subjective measures of benefit. Significant improvements were obtained for speech perception in both quiet and noise. For speech understanding in quiet, mean scores improved from 52% to 71% and in noise (+10 or +5 dB SNR) from 48% to 59%. While accurate localisation remained difficult, it was only with bimodal input that localisation ability was significantly above chance. Investigation of results from the Bimodal Benefit Questionnaire indicated the greatest perceived benefits were in terms of speech understanding in noise, localisation, perception of own voice, and perception of music. Following the study, all participants continued to wear the test hearing aid in combination with their cochlear implant and reported high satisfaction with bimodal stimulation. (c) 2004 Elsevier B.V. All rights reserved.