Objective: To investigate safety and efficacy of a new transcutaneous bone conduction hearing implant, over a 3-month follow-up period.
Study design: Prospective, single-subject repeated-measures design in which each subject serves as his/her own control.
Setting: Departments of Otolaryngology at 4 hospitals in Germany and Austria.
Patients: Subjects were 12 German-speaking adults who suffered from conductive or mixed hearing loss. The upper bone conduction threshold limit was set to 45 dB HL at frequencies between 500 Hz and 4 kHz.
Intervention: Implantation of a transcutaneous bone conduction hearing implant.
Main outcome measures: Subjects' speech perception (word recognition scores and SRT 50%) and audiometric thresholds (air conduction, bone conduction and sound field at frequencies 500 Hz to 8 kHz) were assessed preoperatively, 1 month postoperatively and 3 months postoperatively. The subjects were monitored for adverse events and given a questionnaire to assess their satisfaction levels.
Results: Speech perception as measured by word recognition scores and SRT 50% improved on average about 78.8% and 25 dB HL, respectively, 3 months after implantation. Aided thresholds also improved postoperatively at all tested frequencies and continued to improve from 1 to 3 months postoperatively. Air conduction and bone conduction thresholds showed no significant changes, confirming that subjects' residual unaided hearing was not deteriorated by the treatment. Only minor adverse events were reported and resolved by the end of the study.
Conclusion: The new transcutaneous bone conduction implant was demonstrated to be safe and effective in adults up to 3 months of device use.