Evaluation of a super powerful bone-anchored hearing system and its users: A retrospective study

Introduction: Although the Baha 5SP has been commercially available for six years, very few studies have been performed on the device's efficacy. The current study aims to evaluate the characteristics and audiological results in patients with severe-to-profound mixed hearing loss fitted with this superpower sound processor. 

Methods: This retrospective evaluation was conducted at a tertiary referral centre where a series of 82 adult patients with severe-to-profound mixed hearing loss were implanted with a percutaneous bone-anchored hearing system and fitted with a superpower sound processor between 2016 and 2019. Patients with incomplete or unreliable audiological data (n = 24) were excluded, resulting in 58 data sets for analysis. The main outcome measures were unaided and aided pure-tone thresholds and aided free-field speech perception in quiet. 

Results: The median unaided air conduction (AC) threshold averaged across 0.5, 1 and 2 kHz (PTA_0.5–2kHz) of all patients was 75 dB hearing loss (HL); the median unaided AC averaged across 1, 2 and 4 kHz (PTA_1–4kHz) was 84 dB HL. For bone conduction and direct bone conduction, the median PTA_0.5–2kHz was 52 and 47 dB HL, respectively. With the superpower device, the median free-field speech reception threshold was 54 dB sound pressure level (SPL), and the median speech perception score at 65 dB SPL was 80%. 

Conclusions: At least 75% of the patients reached a maximum phoneme score of 70%. For patients with lower scores, the superpower device still provides a substantial hearing benefit. This makes the superpower device particularly suitable for patients with severe-to-profound mixed hearing loss with a contraindication for conventional hearing aids and/or cochlear implants.