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.
