Abstract
Introduction: The totally implantable active middle ear implant Esteem® may be considered an effective alternative to conventional hearing aids (cHAs) to manage moderate-to-severe forms of sensorineural hearing loss. This study aimed to provide long-term comparative data of Esteem performances with those achieved by cHA. Methods: From a total of 46 subjects who received unilateral application of Esteem®, and were followed up over the years, ten underwent an audiological assessment that compared the outcomes with those achieved in the contralateral ear by a cHA, considering the initially symmetric auditory thresholds in both ears. Other than pure tone audiometry and speech audiometry in quiet, the assessment was performed by using the adaptive speech in noise, i.e., Matrix test. Results: The mean speech intelligibility in quiet shows in the unaided situation a recognition of 50.7% at 71 dBHL, 71% at 69 dBHL with only contralateral cHA, 92% at 66 dBHL with only Esteem device and 94% at 61 dBHL with Esteem® device and contralateral cHA. The mean speech intelligibility in noise shows in the unaided situation a recognition of 36% at 71 dBHL, 56% at 69 dBHL with only contralateral cHA, 79% at 66 dBHL with only Esteem® device and 84% at 61 dBHL with Esteem® device and contralateral cHA. At Matrix test in the unaided condition, 4 patients reached 50% of intelligibility and the 50% threshold was obtained with a mean sound/noise ratio of +10 dBHL. In the contralaterally aided condition, 10 patients reached a 50% threshold in a condition of mean S/N ratio of +10.6 dBHL. In the Esteem® only and Esteem® plus cHA condition, all patients reached the 50% threshold with a mean S/N ratio of +3.4 dBHL with the Esteem® device and +0.92 dBHL with Esteem® plus a contralateral cHA, with a statistically nonsignificant difference. The mean deviation from the reference value (7.1 dB in the normal hearing population) was 17.1 dBHL, in unaided situation; this condition did not change with only the contralateral cHA (17.6 dBHL), whilst a significant improvement could be identified with only Esteem® device, where the mean deviation was 10.5 dBHL, and mostly with Esteem® device associated with the contralateral cHA, with a value of 8.02 dBHL. Conclusions: The adaptive speech audiometry in noise (Matrix Test) showed that binaural stimulation provides greater benefits in the speech recognition in noise test in comparison to monaural stimulation, especially when this is carried out only by the cHA. However, the Esteem® device allowed to obtain audiological benefits that are significantly superior to those offered by cHAs, especially in cases where the hearing loss is severe and, in some cases, profound, achieving performances almost comparable to those of a cochlear implant.
