Developing an assessment approach for perceptual changes to tinnitus sound characteristics for adult cochlear implant recipients.

OBJECTIVE: To investigate the impact of cochlear implantation on tinnitus suppression, characteristics, localization, and duration.

DESIGN: A cochlear implant (CI) recipient-focused postal questionnaire survey.

STUDY SAMPLE: The questionnaire was posted, with consent, to 100 adults who had received a unilateral CI at the RNTNEH between 1988 and 1999. All adults spoke English as their first language and were postlingually deafened. Sixty-eight adults (38 female, 29 male, one unspecified) aged 31-80 years (mean 61 years) completed and returned the questionnaire without interview.

RESULTS: With the processor 'ON', CI recipients experienced total or partial suppression of tinnitus ipsilateral to their CI in 57% of cases, and in 43% where tinnitus was perceived contralateral to the CI. The percentage of CI recipients who experienced high tone tinnitus was reduced from 60% pre-implant to 29% post-implant with the processor 'ON' while pulsatile tinnitus was reduced from 38% pre-implant to 13% post-implant. CIs were also found to reduce the tonal complexity and duration, and change the source localization of tinnitus post-implantation.

CONCLUSIONS: Perceptual changes to tinnitus can take place post-implantation. Changes can occur within the four categories explored: tinnitus suppression, characteristics, localization, and duration of awareness per day.