Objectives: This study was conducted to demonstrate the safety and efficacy of the Otologics Middle Ear Transducer (MET) Ossicular Stimulator and, in particular, to compare the audiologic benefits of this novel form of electromechanical stimulation with those of conventional acoustical amplification.
Material and methods: A total of 282 patients were implanted with the device in Europe and the USA. Pure-tone audiometry, speech recognition and subjective assessment of benefit were tested before the surgery and 2, 3, 6 and 12 months afterwards. The US patients were fitted with a digital hearing aid for a minimum of 4 weeks prior to surgery, and the same benefit measures were performed with the digital hearing aid and their "walk-in" hearing aid.
Results: Group mean postoperative bone and air conduction thresholds did not change significantly from preoperative levels. Postoperative air conduction thresholds decreased slightly in some individual patients, due to the mass loading effect exerted by the transducer on the ossicles. Sufficient gain was available to reach target prescription levels for moderate to severely impaired hearing individuals. Speech and subjective assessment of patient preference indicated that patients did as well or better with the MET Ossicular Stimulator than with their "walk-in" aid or the standardized digital aid.
Conclusion: The capability of the MET Ossicular Stimulator to provide appropriate gain as a function of degree of hearing loss indicates that the device is a viable treatment for moderate to severe sensorineural hearing loss in adults.