Intraoperative measurement for a new transcutaneous bone conduction hearing implant.

OBJECTIVE: To investigate the possibility of using a modified reverse transfer function (RTF) measurement intraoperatively during surgery of a new transcutaneous bone conduction hearing implant to evaluate the status of the device. METHODS: Tests were performed on a cadaver skull (preclinically) and two conductive hearing loss patients implanted with a new transcutaneous bone conduction implant. During intraoperative activation, the RTF was measured using a microphone attached perpendicularly and directly to the skin in the middle section of the forehead. RESULTS: The RTF could be measured for all frequencies from 500 to 6, 000 Hz. CONCLUSION: The usage of an intraoperative RTF measurement may be a good method to verify the mechanical coupling of the bone conduction floating mass transducer and to test the functional integrity of the implant in an objective way.

Active middle ear implant compared with open-fit hearing aid in sloping high-frequency sensorineural hearing loss.

OBJECTIVE: To compare 2 open-ear hearing solutions for sloping high-frequency sensorineural hearing loss: open-fit hearing aid (HA) and active middle ear implant (AMEI). STUDY DESIGN: Within-subjects prospective design. SETTING: Tertiary referral hospital. PATIENTS AND DEVICES: Fourteen patients with sloping, high-frequency sensorineural hearing loss were recruited from 39 patients previously implanted with an AMEI and 10 agreed to participate, ranging in age from 44 to 73 years (mean, 59 yr). Patients were selected because their hearing thresholds (500-3,000 Hz) qualified them for both AMEI and open-fit HA use. All patients received a Vibrant Soundbridge (Vibrant MED-EL) for an average of 25.1 months before data collection and used their AMEI on a daily basis. The open-fit HA used in this study was the Delta 8000 (Oticon). Both study devices have been fit with the specific fitting strategies as recommended by the manufacturer. MAIN OUTCOME MEASURES: Sound-field hearing thresholds, Freiburger monosyllabic words in quiet, speech reception thresholds for 50% correct recognition for Freiburger numbers and for Oldenburg sentences in quiet, and speech reception thresholds for 50% correct recognition for Oldenburg sentences in noise. RESULTS: Both HA and AMEI conditions showed significantly better sound-field thresholds and speech recognition on monosyllabic word and sentence tests in quiet and in noise than in the unaided condition. A comparison of aided conditions revealed that, in the AMEI-aided condition, high-frequency audibility and speech discrimination scores in quiet and in noise were significantly better than those in the open-fit HA. CONCLUSION: Both open-fit HAs and AMEIs provided audiologic benefit to patients with sloping high-frequency sensorineural hearing loss. However, despite overlapping indication criteria for the 2 devices, performance with the AMEI was significantly better for the AMEI than for the open-fit HA.