Background: The Osia system has received Regulatory Approval in Japan this year. The Japan Otological Society needs to develop the application criteria for the Osia System before initiating clinical use.
Methods: Fifteen members of the committee on hearing implants in the Japan Otological Society discussed the development of the application criteria of the Osia System. The application criteria of the Baha system (2023) and the Bonebridge system (2020) in Japan were referred to.
Results: In the application criteria, three criteria and four exclusion criteria were determined, which were followed by four supplementary items. The three criteria include 1. at least one side of the ear has a conductive or mixed hearing loss; 2. bone-conducted hearing loss at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz with pure tone averaging 55 dB or less; 3. the patient has difficulty wearing an air or bone-conducted or cartilage-conducted hearing aid, or the hearing aid is ineffective.
The board of directors of the society has approved the criteria.
Conclusion: With the newly approved criteria, the clinical use of the Osia system is anticipated to start next year.

Background:
Bone-conduction systems are traditionally indicated for patients with conductive or mixed hearing loss, or single-sided deafness. However, patient-centered decisions and emerging clinical contexts may justify expanded use beyond classical criteria.
Methods:
We report the case of a male patient, aged 46 years who developed left-sided moderate descending sensorineural hearing loss after intensive care treatment for severe COVID-19 infection. Despite intact right ear hearing, he experienced significant difficulties in sound localization and speech perception in noise, along with recurrent external otitis from conventional hearing aid use.
Results:
Audiological evaluation confirmed bone conduction thresholds compatible with Vibrant Soundbridge (VSB) indication. During trials, the patient demonstrated better auditory performance with VSB in speech perception tests. Nonetheless, he expressed superior subjective benefit and comfort using the ADHEAR in Bonebridge testing, especially regarding sound quality and daily usability. Despite bone thresholds not classically meeting Bonebridge candidacy, the patient's decision prioritized functional outcomes and quality of life. The patient underwent to Bonebridge BCP 602 placement under general anesthesia and standard surgical technique. PROMPs and audiological results are reported and showed good performance.
Conclusion:
This case reinforces the importance of individualized assessment and shared decision-making in hearing rehabilitation. It suggests that candidacy for bone-conduction systems might be expanded in selected cases of post-infectious sensorineural hearing loss, particularly when patient-reported outcomes challenge traditional audiometric boundaries.

Background:
The Osia® system has become one of the most commonly used active transcutaneous bone conduction implant solutions in Poland in recent years. In this multicenter study, 20 adult patients with mixed, conductive, or single-sided deafness (SSD) who underwent Osia implantation in one of three specialized otologic centers were evaluated for overall satisfaction and device usage patterns.
Methods:
Beyond subjective patient-reported outcomes collected during clinical interviews, the study incorporates objective data extracted from the Osia Fitting Software (OFS). This software provides a comprehensive overview of processor use, including: – total and average daily use, – hours of consecutive use, – streaming duration, – and program-specific data across diverse acoustic environments.
Results:
The primary objective of this study is to investigate the correlation between OFS-derived usage metrics and patient-reported feedback in order to optimize the sound processor fitting process. This integrated approach aims to support a more personalized and data-driven clinical practice in bone conduction hearing rehabilitation.
Conclusions:
Preliminary findings are currently under analysis and will be presented at OSSEO2025.

Background: Given broad access to three acoustic systems (Baha Connect, Attract, Osia) with overlapping indications (type of hearing loss, fitting range, signal transmission, and surgical procedure elements), internal criteria were developed for selecting the optimal bone conduction solution.
Methods: We selected 4 cases from clinical experience, qualified for different acoustic implants, and identified key factors during medical interviews. Considered factors included audiometric evaluations, the ethology of hearing impairment, previous treatments, surgical procedures, self-assessment of hearing, prior hearing aid use, and other relevant limitations or needs. Assessments included pure tone audiometry, BC-Direct, PTA FF, and the SSQ questionnaire.
Results: All patients showed improvement in PTA FF, ranging from 22.5 ± 4.4 dB SPL to 36.3 ± 7.5 dB SPL. SSQ scores improved significantly with the sound processor compared to without. Better bone conduction thresholds were linked to higher gains in free-field audiometry. Subjective SSQ assessments showed comparable satisfaction, despite differences in hearing loss type and degree. A notable exception was observed in the SSQ spatial domain for the patient with SSD, who rated this parameter the lowest, reflecting the impact of the hearing loss type on spatial perception.
Conclusion: All patients were satisfied with their implant systems and experienced clear auditory benefits. The described devices are effective, and a holistic approach is essential for selecting the optimal solution.

Background:

Transcutaneous bone conduction hearing devices (BCD) are suitable for individuals who have conductive or mixed hearing losses. Prescriptive targets for percutaneous devices are available (e.g., Desired Sensation Level (DSL) BC; Hodgetts & Scollie, 2017) and have been recently modified for transcutaneous BCDs.

In-situ threshold measurements account for skin and soft tissue loss for individual BCD fittings. Due to device differences, reference equivalent threshold force level (RETFL) values per device are required for prescriptions. This project will determine RETFL values for the MED-EL ADHEAR worn on a soft headband and adhesive adapter.

Methods:

Up to 30 normal hearing adults will have audiometric thresholds measured with a B-71 bone conduction transducer and in-situ thresholds using the ADHEAR coupled to a soft headband and adhesive adapter. Force level outputs will be measured with the ADHEAR coupled to a skull simulator in the Audioscan® Verifit 2.

Results:

Audiometric and transcutaneous in-situ thresholds for the soft headband and adhesive adapter coupling will be compared across frequency. Results will provide information about the suitability of using the current DSL BC 2.0 targets with transcutaneous fittings for this device with two coupling methods.

Conclusions:

This project investigates variables that may inform the fitting procedures of the MED-EL ADHEAR worn on a soft headband and adhesive adapter. Results will determine RETFL values in both wearing conditions in a group of normal hearing adults and compare those to the force output levels measured on a clinical skull simulator. This information will support fitting the ADHEAR to current transcutaneous prescriptive targets.

Background: Non-surgical bone conduction devices are routinely fitted to children with long-term or transient conductive hearing loss. Consistent use of hearing aids has been shown to benefit language development (Walker, 2015). At The University of Southampton Auditory Implant Service, clinicians reported inconsistent device use within the paediatric population. This service evaluation aimed to review device use and identify if any intervention was required.

Methods: Device use was recorded for all non-surgical bone conduction users from January 2023 to January 2025, who had attended both a fitting appointment and a review appointment. Two methods were used to record device use:
-Datalogging from the device
-Parental reports from a questionnaire

Device use was categorized as Always (8+), Usually (5-7), Occasionally (2-4) and Never (0-1). Patients were removed from the analysis if the data was missing or could not be accessed.

Results: Device use across this population was lower than expected. Most parents over-reported device use compared to datalogging results.

Conclusion: The limited device use within this population is concerning due to its potential effects on language development. The measures of device use differed substantially in their results, with parents often reporting higher usage than indicated by datalogging. This discrepancy warrants further investigation to understand why parents perceive the device use differently. The next steps should focus on identifying the factors affecting device use within this population and informing families about the impact of limited use on outcomes.

Background:
The fetal heart rate is approximately 120 to 160 bpm. If it is slower than this, it is diagnosed as a decreased heart rate, and if it is faster, it is diagnosed as tachycardia. In this paper, we aim to measure the normal fetal heart rate in pregnant women with mild hearing loss and develop a device that listens to the fetal heartbeat using bone vibration.
Methods:
The fetal heart rate measurement input section used a Polyvinylidene fluoride(PVDF) vibration microphone, and a preprocessing circuit applying an analog filter was designed. A 45~370Hz FIR digital filter was designed for noise removal and heartbeat sound extraction in the signal processing section. In addition, a 2.8W class-D amp. was applied to drive the bone conduction vibrator in the sound reproduction output section.
Results:
Based on the implemented device, heart rate measurements were performed on non-pregnant subjects. During the measurement, the PVDF auscultation microphone had many difficulties in measuring heart rate vibration, so the measurement diaphragm was corrected by adding a 100*100*3mm silicone diaphragm. After correction, in the case of normal heart rate sounds, the buzzer sound and heart rate graph could be confirmed together.
Conclusion:
The vibrator's housing design was somewhat rigid, so the vibration output was sometimes weak, and there was also the problem that low-output noise was not easily eliminated

Background:
Finite element (FE) models of the human head are increasingly utilized to study bone conduction (BC) hearing mechanisms. Prior studies indicate a notable dip in cochlear pressure difference across the basilar membrane (BM) around 3 kHz, predominantly caused by increased pressure within the scala vestibuli (SV). The underlying cause of this pressure anomaly remains unclear, complicating accurate simulation and analysis of BC phenomena. This study investigates how skull bone heterogeneity influences cochlear pressure patterns, aiming to clarify the cause of the observed dip near 3 kHz.
Methods:
A detailed FE model of the human head, including the cochlea and BM, was utilized to examine cochlear pressures in the SV and scala tympani (ST). The skull was segmented into two regions: an upper section encompassing the typical Bone Anchored Hearing Aid (BAHA) attachment site, and a lower section including the mastoid-containing temporal bone. Four combinations of elastic modulus—(upper, lower) = (4, 4), (4, 20), (20, 4), and (20, 20) GPa—were simulated to represent homogeneous and heterogeneous skull bone conditions.
Results:
Results demonstrated that the distinct pressure difference fluctuation observed around 3 kHz significantly diminished or disappeared under heterogeneous skull conditions. Specifically, introducing inhomogeneous material properties (4 GPa and 20 GPa combinations) effectively mitigated the SV pressure peak previously observed, highlighting the influence of bone property variations on BC-induced cochlear pressure distribution.
Conclusion:
Our findings identify critical skull regions impacting SV fluid pressure, providing insights into optimal placement of BC hearing devices to improve auditory outcomes.

Background: Active transcutaneous bone conduction devices (BCDs) have revolutionized the treatment of patients with conductive and mixed hearing loss by improving the transmission of sound energy and decreasing skin-related complications. Adults with active transcutaneous BCDs experience improved audibility and word recognition. The present study assessed the initial outcomes of active transcutaneous BCD use for children under 12 years of age to evaluate the effectiveness of this treatment option in a younger patient population.

Methods: Five pediatric participants, 5-12 years old, with conductive hearing loss underwent implantation of the BONEBRIDGE system as part of a multi-center clinical trial. Participants had unaided bone conduction thresholds of 45 dB HL or better and an air-bone gap of 30 dB HL or greater at two or more frequencies between 500-2000 Hz. Study intervals included baseline/preoperative, surgery, device activation, and 1-, 3-, 6-months post-activation. Measures included unaided and aided hearing detection thresholds and word recognition, and subjective outcomes on Glasgow Children’s Benefit Inventory questionnaire. Safety information was also reviewed during surgery and all post-operative intervals.

Results: All participants experienced improved audibility and word recognition with the BONEBRIDGE system compared to their pre-operative unaided condition. Additionally, parents reported a benefit of the active transcutaneous BCD as compared to pre-operative perceptions.

Conclusion: Use of an active transcutaneous BCD is safe, efficacious, and results in improved audibility and subjective improvement in quality of life for young (5-12 years of age) children with conductive hearing loss.

Background:
The Osia 2 system is designed to compensate for conductive hearing loss, mixed hearing loss or single sided deafness by transmitting amplified acoustic signals to the cochlea through mechanical vibration of the skull bone. There is currently limited data on the impact of this device in children.
The objective of this study was to assess safety outcomes and hearing performance in children 5-17 years of age, fitted with the Osia 2 system.

Methods:
Hearing performance was assessed by comparing pure-tone averages (PTA4), words in quiet (at multiple input levels) and Speech Reception Threshold (SRT) for sentences in noise preoperatively, at initial fitting, and postoperatively at 3- and 6-months. Speech, Spatial and Qualities of Hearing Scale for Parents (SSQ-P) was used to assess subjective outcomes. Adverse events and device deficiencies were used to assess safety outcomes.

Results:
At the time of abstract submission, 3-month data are available and reported. PTA4 improved by 39.7 dB HL (range: 5.0 -57.5 dB HL, p <0.01 . Words in quiet improved by 66.3%, 66.0% and 24.0% at 50-, 65- and 80 dB SPL, respectively . Sentences in noise (SRT) improved by 9.5dB. The (SSQ-P) improved by 2.3 points. Safety outcomes were found to be consistent with those obtained in patients 18 years and older. Longer term outcome data will be presented at the time of conference.

Conclusion:
The Cochlear™ Osia® 2 System provided significant improvements in hearing outcomes and subjective hearing benefits. No new safety signals were reported in this young cohort.

Background:
Sound-field audiometry in patients with unilateral and asymmetric hearing loss is challenging because of the need for contralateral ear occlusion or masking, which can compromise results. This ongoing study aims to evaluate whether direct audiometry via the audio processor offers a reliable method for ear-specific assessment in clinics.

Methods:
So far, we included 7 patients (age 10-78 years; 4 CI, 3 VSB). Five patients had unilateral deafness/asymmetrical hearing loss, while two were controls with a contralaterally profoundly deaf ear. All patients underwent conventional sound-field audiometry, with occlusion or masking of the contralateral ear. Additionally, direct measurements were performed using a CE-certified audiometer with calibrated line output. Aided thresholds, speech understanding in noise (S0N0), and in quiet (Freiburg monosyllables at 50, 65, and 80 dB SPL) were compared. All tests were performed in a counter-balanced order in an acoustic chamber.

Results:
Preliminary data suggests that direct measurements are comparable for aided hearing thresholds (averaged difference ±5 dB) and speech understanding (averaged OLSA SRT difference -0.5 dB; averaged difference for monosyllables max. 10%) in the controls. In the other patients, we observed worse performance with the direct method in particular for speech in quiet at 80 dB SPL (-23%) and in noise (+2.8 dB) that may be attributed to insufficient contralateral occlusion or masking during standard testing. All patients preferred the direct method.

Conclusion:
Direct implant audiometry could be an alternative to conventional sound-field testing. While early results are promising, further data from a larger cohort is needed to draw substantial conclusions.

Background:
Feedback is a common phenomenon that limits available gain in bone conduction devices (BCDs). The feedback limit of a BCD differs between users and between devices. In this presentation we will propose a method for assessing the feedback limit, also referred to as maximum stable gain (MSG) and assess this MSG for two modern power BCD’s. The MSG was compared with the Full On Gain (FOG). This data contributes to objectively comparing and selecting a BCD for a single patient, in line with a request for these data (Maier 2022).
Methods:
During the visit for a new BCD, the feedback limit was assessed for 42 patients with their BCD on their percutaneous implant, using the proprietary software used to fit the BCD. Subsequently, the BCD gain was temporarily set at the individual MSG and the gain was measured on a skull-simulator with an 55 dB ISTS input signal.
For two new power BCDs’ the the full-on gain was also measured on a skull-simulator with an 55 dB ISTS input signal in a testbox.
Results:
The average and range of the MSG for 0.5 – 4 kHz were 12 ± 4 dB for device 1 and 16 ± 6 dB for device 2. These were below the FOG of 13 and 22 dB respectively.
Conclusions:
The maximum available gain of percutaneous power BCDs is primarily determined by the maximum stable gain in most BCD users and not by the full-on gain. This feedback limit arises from both device and individual user factors.