Background:
Bone conduction (BC) delivers sound via skull vibration, but transient stimulus timing and bilateral propagation remain poorly understood. This study aimed to (1) quantify propagation delay and motion composition from stimulation sites to each cochlea using impulse stimuli; (2) evaluate bilateral BC stimulation effects on otic capsule motion and intracochlear pressure versus unilateral stimulation.
Methods:
Five fresh-frozen human cadaver heads received percutaneous mastoid and forehead stimulation via a bone-anchored actuator using continuous sweeps to estimate impulse responses. For each head, 3D laser Doppler vibrometry recorded promontory and medial skull bone surface (specifically near the otic capsules) velocities for ipsi- and contralateral cochleae, while intracochlear receivers measured scala tympani pressure. Impulse responses yielded propagation delays, time constants, and directional motion contributions for bilateral and unilateral stimulation.
Results:
Preliminary data from five heads show a mean propagation time of approximately 200-300 µs between the two cochleae, and a mean delay of about 100-150 µs from stimulus onset to ipsilateral cochlear activation. These transient-response measurements confirm rapid interaural transmission and show distinct timing and spatial differences between ipsilateral and contralateral stimulation in BC.
Conclusion:
These preliminary findings demonstrate that transient BC stimuli can be used to differentiate and quantify propagation delays to each cochlea, and that bilateral stimulation elicits measurable intracochlear pressure and motion patterns distinct from unilateral excitation. This methodology lays the groundwork for improved understanding of bilateral BC pathways and may inform the design of future bilateral bone‐conduction hearing devices.

Background: Active transcutaneous devices take advantage of efficient direct vibration transmission to the cranial bone. The new active transcutaneous bone conduction system Sentio™ (Oticon Medical AB, Askim, Sweden) has been launched in septembre 2024. The implant is currently approved for use from the age of 12. Due to its compact design with a height of 4 mm and a bone recess depth of maximum 3 mm, we also expect advantages for younger patients.
Methods: 6 children aged between 4 and 12 years with an indication for a bone conduction hearing system were implanted uni- and bilaterally with 10 Sentio™ system in an off-label agreement. A CT-scan was performed prior to determine bone thickness and the correct positioning of the implant. In accordance with our clinical practice, follow-up examinations were carried out after 4 weeks and 3, 6 months after implantation. Aspects relating to the operation, audiology and subjective assessments with a questionnaire were analyzed.
Results: The implantation was performed without complications in all cases, with little preoperative planning, and the postoperative phase was also uneventful. Audiological examinations showed a significant improvement in the hearing threshold. Subjectively, the quality of life after the intervention.
Conclusion: The compact specifications of the Sentio™ system proved favorable for implantation children. It showed to be effective and safe for improving hearing in younger patients with conductive hearing loss. There were no serious intraoperative or postoperative complications.

Background:

The Minimally Invasive Ponto Surgery (MIPS) was launched in 2015 as a straightforward, fast single-stage surgical solution designed to minimize postoperative complications and deliver improved cosmetic outcomes for placement of percutaneous bone anchored hearing systems (BAHS). Patient reported sound processor usage and quality-of-life impacts were measured across one year following BAHS placement with MIPS.

Methods:

Sixty-four adult patients undergoing BAHS treatment using the MIPS participated in a 12-month prospective, multinational, multicenter single-arm investigation. Sound processor time to loading and average daily sound processor usage were recorded. Patient-reported outcomes were assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) and Glasgow Benefit Inventory (GBI) at varying timepoints.

Results:

The sound processor was loaded onto the implants on average 45 ±22 days after MIPS. At 3-months, 6-months, and 12-months after MIPS patients reported using their sound processor, on average, 9.8, 9.9, and 9.2 hours per day, respectively.

The APHAB global scores showed a significant improvement in hearing and communication abilities, at 6-months following MIPS (27.8) as compared with pre-operative, unaided abilities (50.8), p<0.001.

The GBI was completed at 3- and 12-months following MIPS, with 93% and 98% of patients at these respective timepoints reporting improvements in their overall quality of life.

Conclusion:

Positive effects on quality of life can be expected following BAHS placement with MIPS.

Background:
The active transcutaneous Bone Conduction Implant (atBCI) Bonebridge is a well-established treatment option for conductive hearing loss (CHL), mixed hearing loss (MHL), and single-sided deafness (SSD). It offers amplification to those who cannot use or do not benefit from conventional hearing aids. The second generation (BCI 602) is available since 2019. In St Pölten, the BB program started in 2012. Here, we present data on safety and performance of the BCI 602.
Methods:
In this multicentric study 24 adults and 17 children treated for CMHL and 11 patients treated for SSD were analyzed. Performance was assessed by improvements in sound field thresholds (SF PTA4), word recognition scores (WRS) and speech reception thresholds in quiet and in noise (SRT /SNR). Safety was assessed by stable bone conduction thresholds (BC PTA4) and adverse event reporting. Review of the surgery was further used to assess the new design features of the BCI 602.
Results:
Safety was established by stable BC thresholds, and now reporting of unanticipated events. Performance was significantly improved 12 months after surgery in SF PTA4 (Δ 21.34 dB (CMHL children), Δ 24.05 dB (CMHL adults) and Δ 26.43 dB (SSD)), WRS (Δ 65.77 PP (CMHL children) and Δ 64.57 PP (CMHL adults)) and SNR (Δ -6.21 dB (CMHL children), Δ -5.57 dB (CMHL adults) and Δ -3.51 dB (SSSDNNH)).
Conclusions:
The findings of this study demonstrate that safety and performance are proven for the BCI 602 for all indications 12 months post operatively.

Background: Patients with Trisomy 21 are known to be more at risk of conductive hearing loss, due to craniofacial anatomical differences most commonly leading to increased risk of otitis media with effusion. While use of bone conductive hearing implants (BCHI) have previously been evaluated in children, we look at a novel series of use of BCHI in adults with Trisomy 21 at Queen Elizabeth Hospital, Birmingham (QEHB).

Methods: Review of electronic patient records on all adult patients with Trisomy 21 at QEHB who received or had been transferred to our care with a BCHI over the past 10 years was undertaken, with data gathered on: demographics, type of hearing rehabilitation tried prior to BCHI, type of implant and aid, postoperative complications, and pre and post implant hearing outcomes.

Results: Initial results show a variety of BCHIs used, with a few early post-operative complications. Later complications included failure of osseointegration. Overall hearing outcomes were positive, and a significant proportion of patients continue to use their bone anchored hearing aids postoperatively despite initial complications.

Conclusion: Use of BCHIs is a viable option for hearing rehabilitation in adults with Trisomy 21. Most patients tolerated the procedure well under local anaesthesia and successfully learnt to use their aids. Few patients underwent bilateral implantation, an area worth exploring further in future. Overall complications following implantation were outweighed by benefits as shown by continued use of the hearing aids, and improvement in hearing outcome.

Background:
Fitting of bone-conduction hearing devices can be difficult when patients are unable to cooperate, such as in young children, so an objective method for assessing hearing performance would be desirable. Analysis of Cortical Auditory-Evoked Potentials (CAEP) can be a helpful method for estimating the efficiency of such devices.
Methods:
CAEP measurements were carried out with the bone conduction device Ponto 5 (Oticon Medical). Speech-like narrowband stimuli were used described by Stone et al. [1]. Stimuli were presented in free sound field at two different stimulation levels (65 and 45 dBSpRefL) to fifteen normally hearing participants with simulated hearing loss.
Results:
In a total of 60 measurements, 93.3% and 56.7% CAEP were identified at stimulation levels of 65 and 45 dBSpRefL, respectively. Typical CAEP Amplitudes (P1, N1, P2) were slightly, but not significantly, larger unaided compared to aided condition. The latencies also did not differ significantly.
Conclusion:
The measurement method presented shows that CAEP can be reliably recorded via a bone conduction device. This allows an objective verification of the fitting when subjective test procedures cannot be performed.
References:
[1] M. A. Stone, A. Visram, J. M. Harte, and K. J. Munro, ‘A Set of Time-and-Frequency-Localized Short-Duration Speech-Like Stimuli for Assessing Hearing-Aid Performance via Cortical Auditory-Evoked Potentials’, Trends Hear, vol. 23, 2019.