Clinical Performance Assessment of a New Active Osseointegrated Implant System in Mixed Hearing Loss: Results From a Prospective Clinical Investigation

OBJECTIVE

Evaluation of a new active osseointegrated bone-conduction hearing implant in moderate to severe mixed-hearing loss.

STUDY DESIGN

Prospective observational study of a series of cases.

SETTING

Tertial referral center.

PATIENTS

Twenty patients with moderate mixed-hearing loss were evaluated (10 Cochlear Osia group and 10 Baha 5 Power Connect -control group).

INTERVENTION

Rehabilitative.

MAIN OUTCOME MEASURES

Hearing performance in quiet and in noise and quality-of-life were evaluated.

RESULTS

Improvements in audibility, speech-understanding, speech-recognition, and quality-of-sound in noise and quiet were found for the Osia System compared with preoperative unaided hearing and performance was similar to that obtained with Baha 5 Power Connect.

CONCLUSIONS

The new active transcutaneous bone conduction system provided a tonal improvement in free-field at middle and high frequencies. The performance in speech recognition in quiet and in noise was similar to control group outcomes.

Power output and hearing performance in osseointegrated auditory devices

BACKGROUND AND OBJECTIVE

Osseointegrated auditory devices are hearing gadgets that use the bone conduction of sound to produce hearing improvement. The mechanisms and factors that contribute to this sound transmission have been widely studied, however, there are other aspects that remain unknown, for instance, the influence of the processor power output. The aim of this study was to know if there is any relationship between the power output created by the devices and the hearing improvement that they achieve.

MATERIALS AND METHODS

Forty-four patients were implanted with a percutaneous Baha® 5 model. Hearing thresholds in pure tone audiometry, free-field audiometry, and speech recognition (in quiet and in noise) were measured pre and postoperatively in each patient .The direct bone conduction thresholds and the power output values from the processors were also obtained.

RESULTS

The pure tone average threshold in free field was 39.29dB (SD 9.15), so that the mean gain was 29.18dB (SD 10.13) with the device. This involved an air-bone gap closure in 63.64% of patients. The pure tone average threshold in direct bone conduction was 27.6dB (SD 10.91), which was 8.4dB better than the pure tone average threshold via bone conduction. The mean gain in speech recognition was 39.15% (SD 23.98) at 40dB and 36.66% (SD 26.76) at 60dB. The mean gain in the signal-to-noise ratio was -5.9dB (SD 4.32). On the other hand, the mean power output values were 27.95dB μN (SD 6.51) in G40 and 26.22dB μN (SD 6.49) in G60. When analysing the relationship between bone conduction thresholds and G40 and G60 values, a correlation from the frequency of 1,000Hz was observed. However, no statistically significant association between power output, functional gain or speech recognition gain was found.

CONCLUSIONS

The osseointegrated auditory devices generate hearing improvement in tonal thresholds and speech recognition, even in noise. Most patients closed the air-bone gap with the device. There is a direct relationship between the bone conduction threshold and the power output values from the processor, but only in mid and high frequencies. However, the relationship between power output and gain in speech recognition is weaker. Further investigation of contributing factors is necessary.