ABSTRACT
CONCLUSION: The benefit obtained with a contralateral hearing aid (HA) in unilateral cochlear implantees improves over time, at least during the first year after implantation. OBJECTIVE: To evaluate binaural-bimodal auditory ability and its early changes over time after unilateral cochlear implantation in patients with residual hearing in the non-implanted ear, in which they use an HA. MATERIAL AND METHODS: Sentence identification in background noise was tested in 12 patients (3 post-lingual adults and 9 pre-lingual adults and older children) under 3 listening conditions: cochlear implant (CI) alone, HA alone and CI+HA. The presentation level was 55 dB HL with a signal-to-noise ratio of +10 dB. Subjects were tested after 1-6 months of concomitant use of both devices and again after a further 7-12 months. RESULTS: At the first testing session, the mean score in background noise was 34.9% with CI alone (range 0-90%) and 41.1% with both devices (range 0-100%). Seven patients could recognize sentences in noise with CI alone, and four of them showed further improvement with added amplification. At the second session, at which all subjects could recognize sentences in noise with the CI alone, seven showed further improvement with added amplification. The mean score was 60.6% with CI alone (range 10-99%) and 75.5% with both devices (range 52-100%).
Subject(s)
Auditory Threshold , Cochlear Implants , Hearing Aids , Hearing Loss, Sensorineural/rehabilitation , Speech Perception , Adolescent , Adult , Audiometry, Pure-Tone , Child , Female , Humans , Male , Middle Aged , Speech Reception Threshold Test , Treatment OutcomeABSTRACT
OBJECTIVES: To evaluate sound localization ability in totally deaf patients with unilateral cochlear implants and to estimate the ability to improve this function by training. DESIGN: A controlled case series. MATERIALS AND METHODS: Nine patients with monaural cochlear implants were asked to identify the source of 50 randomly distributed sound stimuli coming from five different directions anteriorly or laterally. After some training, patients were retested. There were two control groups. One comprised nine adults with normal hearing, and the other comprised nine adults with normal hearing but one ear plugged. RESULTS: The mean initial score of the study group (maximal score 100) was 41.5 (range 23-63). Patients who had used cochlear implants longer had better sound localization ability (Spearman's correlation coefficient = 0.92). On retesting, after an average of 6.3 training sessions, their mean score improved to 66 (range 32-95), (p = 0.008). The improvement was more pronounced in postlinguals than in prelinguals (p = 0.016). CONCLUSIONS: Spontaneous development of sound localization ability in totally deaf patients with unilateral cochlear implants is proportional to the time interval between implantation and initial testing. Improvement appears to be influenced by training, and to be greater in postlingual than in prelingual implantees.
