Comparative effects of unilateral and bilateral bone conduction hearing devices on functional hearing and sound localization abilities in patients with bilateral microtia-atresia

Bilateral adhesive bone conduction devices in patients with congenital bilateral conductive hearing loss

PURPOSE

This study aims to characterize the hearing benefits and sound localization accuracy of bilateral adhesive bone conduction devices (aBCDs) compared to unilateral devices in patients with congenital bilateral conductive hearing loss (BCHL).

METHODS

Sixteen children and adolescents with congenital BCHL were enrolled and tested under four listening conditions: (1) unaided, (2) R aided: aided with a right-side aBCD, (3) L aided: aided with a left-side aBCD, and (4) B aided: aided with aBCDs on both sides. The sound field hearing threshold (SFHT, in dB hearing level [HL]) and the word recognition score (WRS) were measured. The mean absolute error (MAE) of sound source localization was calculated to assess the sound localization accuracy.

RESULTS

The performance in SFHT and WRS was significantly higher in the B aided condition than that in the unaided, R and L aided conditions; moreover, no significant difference was observed between the R and L aided conditions. Concerning sound source localization, the accuracy of localization exhibited a sharp decline when using a single aBCD, while the application of bilateral aBCDs (B aided condition) resulted in a significantly improved localization accuracy as compared to the unilaterally aided conditions (both R and L); however, no significant difference was found between the unaided and B aided condition.

CONCLUSION

Patients with congenital BCHL experienced suboptimal hearing benefits and manifested significant challenges in sound source localization when utilizing a single aBCD, as compared to the utilization of bilateral aBCDs.

Multicentric study on surgical information and early safety and performance results with the Bonebridge BCI 602: an active transcutaneous bone conduction hearing implant

AIM

This European multicentric study aimed to prove safety and performance of the Bonebridge BCI 602 in children and adults suffering from either conductive hearing loss (CHL), mixed hearing loss (MHL), or single-sided sensorineural deafness (SSD).

METHODS

33 patients (13 adults and 10 children with either CHL or MHL and 10 patients with SSD) in three study groups were included. Patients were their own controls (single-subject repeated measures), comparing the unaided or pre-operative to the 3-month post-operative outcomes. Performance was evaluated by sound field thresholds (SF), word recognition scores (WRS) and/or speech reception thresholds in quiet (SRT) and in noise (SNR). Safety was demonstrated with a device-specific surgical questionnaire, adverse event reporting and stable pure-tone measurements.

RESULTS

The Bonebridge BCI 602 significantly improved SF thresholds (+ 25.5 dB CHL/MHL/SSD), speech intelligibility in WRS (+ 68.0% CHL/MHL) and SRT in quiet (- 16.5 dB C/MHL) and in noise (- 3.51 dB SNR SSD). Air conduction (AC) and bone conduction (BC) thresholds remained stable over time. All adverse events were resolved, with none unanticipated. Mean audio processor wearing times in hours [h] per day for the CHL/MHL group were ~ 13 h for adults, ~ 11 h for paediatrics and ~ 6 h for the SSD group. The average surgical length was 57 min for the CHL/MHL group and 42 min for the SSD group. The versatility of the BCI 602 (reduced drilling depth and ability to bend the transition for optimal placement) allows for treatment of normal, pre-operated and malformed anatomies. All audiological endpoints were reached.

CONCLUSIONS

The Bonebridge BCI 602 significantly improved hearing thresholds and speech understanding. Since implant placement follows the patient's anatomy instead of the shape of the device and the duration of surgery is shorter than with its predecessor, implantation is easier with the BCI 602. Performance and safety were proven for adults and children as well as for the CHL/MHL and SSD indications 3 months post-operatively.

Simultaneous bilateral transcutaneous bone conduction device implantation: sound localisation and speech perception in children with bilateral conductive hearing loss

Objective

This study investigated the audiometric and sound localisation results in patients with conductive hearing loss after bilateral Bonebridge implantation.

Method

Eight patients with congenital microtia and atresia supplied with bilateral Bonebridge devices were enrolled in this study. Hearing tests and sound localisation were tested under unaided, unilateral and bilateral aided conditions.

Results

Mean functional gain was higher with a bilateral fitting than with a unilateral fitting, especially at 1.0–4.0 kHz (p < 0.05, both). The improvement in speech reception threshold in noise with a bilateral fitting was a 2.3 dB higher signal-to-noise ratio compared with unilateral fitting (p < 0.05). Bilateral fitting had better sound localisation than unilateral fitting (p <0.001). Four participants who attended follow up showed improved sound localisation ability after one year.

Conclusion

Patients demonstrated better hearing threshold, speech reception thresholds in noise and directional hearing with bilateral Bonebridge devices than with a unilateral Bonebridge device. Sound localisation ability with bilateral Bonebridge devices can be improved through long-term training.

Multicenter Results With an Active Transcutaneous Bone Conduction Implant in Patients With Single-sided Deafness

OBJECTIVE

To evaluate the audiological and subjective benefit from hearing rehabilitation with an active bone conduction implant in subjects with single-sided sensorineural deafness (SSD).

STUDY DESIGN

Prospective, multicenter, single-subject repeated measures.

SETTING

Tertiary referral center, five clinics in Germany and Switzerland.

PATIENTS

Seventeen subjects aged 18 years and older with severe to profound unilateral sensorineural hearing loss and contralateral normal hearing were followed up for 24 months.

INTERVENTION

Active bone conduction implant.

MAIN OUTCOME MEASURES

Speech understanding in noise was assessed in three situations: with signal from front, deaf, or normal hearing side (with noise from front in all set-ups). Subjective benefit was evaluated using the Speech, Spatial, and Qualities of Hearing (SSQ-B) and Bern Benefit in Single-Sided Deafness (BBSS) questionnaire.

RESULTS

When the signal was coming from the deaf side the mean improvement of the speech reception threshold in noise ranged from 1.5 up to 2.2 dB with the device and was statistically and clinically significant at all tested timepoints. No significant difference between the aided and unaided situation was found when signal and noise were coming from the front. With the signal from the normal hearing side no clinically significant difference, that is, greater than 1 dB between the aided and unaided situation was found. The SSQ-B and BBSS questionnaire showed an overall improvement with no significant difference between time points.

CONCLUSIONS

The study demonstrates long-term efficacy and benefit of the device in adults with SSD. Patients reported substantial and persistent subjective benefit from the active bone conduction implant.

Sound Localization and Lateralization by Bilateral Bone Conduction Devices, Middle Ear Implants, and Cartilage Conduction Hearing Aids

Sound localization in daily life is one of the important functions of binaural hearing. Bilateral bone conduction devices (BCDs), middle ear implants, and cartilage conduction hearing aids have been often applied for patients with conductive hearing loss (CHL) or mixed hearing loss, for example, resulting from bilateral microtia and aural atresia. In this review, factors affecting the accuracy of sound localization with bilateral BCDs, middle ear implants, and cartilage conduction hearing aids were classified into four categories: (1) types of device, (2) experimental conditions, (3) participants, and (4) pathways from the stimulus sound to both cochleae. Recent studies within the past 10 years on sound localization and lateralization by BCDs, middle ear implants, and cartilage conduction hearing aids were discussed. Most studies showed benefits for sound localization or lateralization with bilateral devices. However, the judgment accuracy was generally lower than that for normal hearing, and the localization errors tended to be larger than for normal hearing. Moreover, it should be noted that the degree of accuracy in sound localization by bilateral BCDs varied considerably among patients. Further research on sound localization is necessary to analyze the complicated mechanism of bone conduction, including suprathreshold air conduction with bilateral devices.

Device profile of the Bonebridge bone conduction implant system in hearing loss: an overview of its safety and efficacy

INTRODUCTION

The Bonebridge is an active transcutaneous semi-implantable bone conduction hearing device suitable for several types of hearing loss. It has unique benefits over some more established technologies. It consists of an internal active implant and an external sound processor. It was first launched in 2012, with a newer model released in late 2019.

AREAS COVERED

The structure and features of the device are described. Indications, audiological criteria, and contraindications to implantation are discussed. The planning and procedure of implantation surgery are also described. Research outlining the outcomes of implant use and risk of adverse events is highlighted.

EXPERT OPINION

The evidence included in this article demonstrates the successful audiological outcomes and patient satisfaction with Bonebridge implantation. The rate of adverse events following surgery is low and compares well with other devices which may be considered for Bonebridge candidates. The device should be considered as an option for suitable candidates and in many cases may be the better option available, given the low incidence of skin complications and the absence of a skin penetrating abutment. Future advances are likely to affect sound processor technology, connectivity, and possibly further reduction in implant size and gain.