Background: Bilateral hearing is important for learning, development, and function in complex everyday environments. Children with conductive and mixed hearing loss (HL) have been treated for years with percutaneous coupling through an abutment, which achieves powerful output, but the implant site is susceptible to skin reactions and trauma. To overcome these complications, transcutaneous magnetic coupling systems were recently introduced.
Purpose: The purpose of the study was to evaluate whether the new transcutaneous magnetic coupling is an effective coupling paradigm for bone-conduction hearing aids (BCHAs). We hypothesized that magnetic coupling will (1) have limited adverse events, (2) provide adequate functional gain, (3) improve spatial hearing and aid listening in everyday situations, and (4) provide satisfactory outcomes to children and their families given one normal hearing ear.
Research Design: Retrospective analysis of audiological outcomes in a tertiary academic pediatric hospital.
Study Sample: Nine children aged 5–17 yr with permanent unilateral conductive HL (UCHL) or mixed HL were implanted with a transcutaneous magnet–retained BCHA. Average hearing thresholds of the better and implanted ears were 12.3 ± 11.5 dB HL and 69.1 ± 11.6 dB HL, respectively, with a 59.4 ± 4.8 dB (mean ± standard deviation) conductive component.
Data Collection and Analysis: Data were extracted from audiology charts of the children with permanent UCHL or mixed HL who qualified for a surgically retained BCHA and agreed to the magnetic coupling. Outcomes were collected from the 3- to 9-mo follow-up appointments, and included surgical complications, aided audiometric thresholds with varying magnet strength, speech performance in quiet and noise, and patient-rated benefit and satisfaction using questionnaires. Repeated measures analysis of variance was used to analyze audiometric outcomes, and nonparametric tests were used to evaluate rated benefit and satisfaction.
Results: All nine children tolerated the device and only one child had discomfort at the wound site. Similar access to sound was achieved regardless of magnet strength. Speech performance did not significantly improve in quiet or noise conditions with +10 and +5 dB signal-to-noise ratio. Children benefited from spatially separating the noise from the speech signal, regardless of whether the noise was directed to the implanted or better ear. When wearing the BCHA, the children reported satisfaction and significant implant benefit, particularly in background noise, but at the expense of increased aversiveness to sound.
Conclusions: Our findings, therefore, indicate that providing a transcutaneous magnetic-coupled BCHA to children who have UCHL or mixed HL provides benefit on some objective measures of bilateral hearing, as well as some subjective benefit in noise and everyday situations.
ADHEAR in Conductive Hearing Loss: a case study
