Post-market Clinical Follow-up of a Magnetic Bone Conduction Implant (Cochlear Baha Attract System)

This investigation was designed to collect data regarding the usability and clinical performance of the Baha Attract System in subjects with hearing impairment that were candidates for Baha surgery. The investigation was performed in an open design since it was not possible to perform the investigation in a blinded fashion. The main evaluations of the investigation, i.e. free-field hearing tests, are standard audiological procedures that are routinely used in daily clinical practice at hospitals worldwide for evaluation of hearing performance in hearing impaired patients. The primary efficacy evaluation, audiometric thresholds, renders comparable results across different sites and countries as it is not a language-specific test. Language-specific audiological tests were performed as secondary efficacy evaluations; to enable comparison of data across sites, validated word lists were used at all sites and equivalent speaker configurations (speech from front, noise from behind) and test procedures (same noise and adaptive speech levels, etc) were used. For the primary evaluation in the investigation, the Baha Attract System was compared to the pre-operative unaided situation, as the intended use of the system is to improve hearing performance in patients with conductive or mixed hearing loss or single-sided sensorineural deafness. Audiological test results with the Baha Attract System were also compared against results obtained with the same Sound Processor on a Baha Softband. Use of the Sound Processor on a Softband is a standard procedure that is routinely used as a pre-operative test prior to bone conduction hearing implant surgery. The Softband test allows the patient to pre-operatively experience hearing through the Sound Processor to get an indication of the post-operative hearing outcome and to choose a suitable Sound Processor. The generic and hearing-specific quality of life questionnaires used in the investigation (HUI3, APHAB, SSQ) are validated scales that have been frequently used and reported in the literature.