Introduction:
Cochlear implantation (CI) in asymmetric hearing loss or single sided deafness aims at improvement of speech perception in noise as well as quality of life. This study evaluates posttherapeutic changes compared to the unaided condition as well as persisting subjective deficits.
Methods:
Adult Cochlear-Implant users with at least 9 months listening experience and an average hearing loss of less than 55dB on the contralateral ear were included. Binaural speech reception thresholds (SRT) were determined adaptively in 4 loudspeaker settings and 2 listening conditions. Individual handicap due to hearing impairment, dizziness or chronic tinnitus was evaluated with standardized questionnaires.
Results:
Etiology and duration of deafness varied widely between subjects as did individual SRT. However, most patients demonstrated significant benefit with the CI compared to the unaided condition, when noise was presented from the acoustic hearing side and speech was directed towards the implanted ear. Subjective handicap due to dizziness or tinnitus was low, however 50 percent of the patients felt still a severe hearing impairment.
Conclusion:
Cochlear implantation can improve some deficits of asymmetric hearing loss or single sided deafness. Impairment due to dizziness or tinnitus was generally low. Potential negative factors with influence on the outcome should be discussed with all patients prior to implantation.
