We conducted a retrospective descriptive study of a series of 31 consecutively presenting patients who had been implanted with the Vibrant Soundbridge middle ear hearing device. All implantations had been performed by the senior author. Three of these patients had undergone bilateral implantation, and 4 others had undergone subsequent explantation and reimplantation in response to known or suspected device failure, giving us a total of 34 ears and 38 implants. Our goal was to ascertain short- and long-term outcomes as measured by conventional audiometry (pure-tone average at 1 to 6 kHz) and long-term benefit as defined by the use or nonuse of the device. We found that at the initial activation session 2 months postoperatively, the average hearing thresholds were within 3 dB of the preoperative thresholds in all 34 ears and all 38 implants. The mean short-term gain at activation in the 38 implants was 28.1 dB. Nineteen patients (20 ears) were available for long-term evaluation, with the length of follow-up ranging from less than 1 year to 11 years (mean: 7.3). Of these 20 ears, 9 demonstrated further gain (mean: 10.8 dB) despite any natural hearing deterioration; of the remaining 11 ears, gain was unchanged in 2, diminished in 7 (mean: -3.6 dB), and gain data were unavailable in 2. In the final analysis, there were 20 user ears and 10 nonuser ears; 4 ears were lost to all follow-up. We conclude that direct-drive hearing with the Vibrant Soundbridge middle ear hearing device is beneficial and provides sustained audiometric gain. Factors that have a significant impact on patient use or nonuse include difficulty in obtaining audiologic support and the direct and indirect costs of the device. Without audiologic or financial support, some patients may choose to become nonusers and to either switch to conventional hearing aid amplification or become apathetic about hearing improvement.
In 1996, Symphonix Devices, Inc., asked the senior author (C.M.L.) to evaluate direct vibration of the ossicular chain during surgery under local anesthesia to establish the feasibility of developing a wearable device for the treatment of sensorineural hearing loss.1 The first 4 Vibrant Soundbridge middle ear hearing devices with a floating mass transducer (FMT) were implanted in the United States by the senior author in 1996 and 1997.