Application of Active Middle Ear Implants in Patients With Severe Mixed Hearing Loss

Objective: To determine the long-term benefit of the Vibrant Soundbridge (VSB) middle ear implant in patients with severe mixed hearing loss and to compare it with other hearing devices. Design: A retrospective analysis. Setting: University-affiliated medical center. Patients: Six patients with severe mixed hearing loss and a mean sensorineural hearing loss component between 40 and 70 dB. Interventions: Patients received a VSB with the floating mass transducer (FMT) coupled to the round window or to the oval window via a residual stapes structure. Main Outcome Measures: Functional gain and speech recognition results. Results are compared with 2 control groups matched for mean sensorineural hearing loss: 1) patients with mixed hearing loss and a bone-anchored hearing device, and 2) patients with sensorineural hearing loss and traditional implantation of the VSB. Results: There is large variance in functional gain between the patients suggesting high variability in the effectivity of the FMT coupling. The speech recognition results for the experimental group were not systematically better than in either control group. Conclusion: There is large variability in results that might be ascribed to coupling effectivity. On the average, speech recognition results were not better or worse than those found in patients with similar hearing loss fitted with bone-anchored hearing devices.