Bone Conduction Implants Research Articles

Prvé skúsenosti s implantátom pre kostné vedenie zvuku Sophono

ntroduction: Bone conduction implants are currently used for rehabilitation of conductive and mixed hearing loss as well as for single sided deafness. A growing number of these implants available on the market increases requirements on detailed knowledge on their technical properties, and on their advantages and disadvantages in clinical practice. Sophono is one of the recent members in this implant group. The aim of the study is to summarize our first experiences with Sophono at our implantation center in Bratislava. Patients and methods: We present data of the first two adult patients who underwent Sophono implantation. Both suffered from bilateral conductive hearing loss of different etiology. We focused on their audiological functional outcomes, basic surgical aspects and subjective assessment by the patients. Results: In free field tone audiometry with the implant, both patients achieved improvement of hearing thresholds by 21.25 dB and 31.25 dB, respectively. In speech tests with and without noise, we also demonstrated a clear benefit of the implant, which was in a narrow relationship with the degrees of their hearing loss: speech discrimination scores in noise were 30% and 60% in patients 1 and 2, respectively. The surgical procedure in Sophono implantation is relatively simple and does not include any work on middle ear structures. Patient satisfaction with the implant does not always correspond to the measured functional outcomes. Conclusion: The Sophono implant represents a suitable option for rehabilitation of conductive and mixed hearing loss as well as single sided deafness in selected patients. The candidate selection is always based on comprehensive assessment in which the audiological results are an elementary criterion, but definitely not a single one. Keywords: Sophono – implantation – conductive hearing loss

Rehabilitace jednostranné hluchoty pomocí implantabilního systému pro přímé kostní vedení – Bonebridge

Overview Introduction: Bonebridge is a direct bone conduction hearing implantable system. The aim of the work is to present pilot results of rehabilitation of single sided deafness using this system. Material and methods: Analysis of three patients with single-sideded deafness, who underwent BB implantation in 2018 at the Department of Otorhinolaryngology and Head and Neck Surgery of St. Anna Hospital in Brno. Evaluation parameters: Bern Benefi t in Single-Sided Deafness Questionnaire, experimental examination of directional hearing and hearing in noise test. Results: Questionnaire: Within the visual analog scale in the range of –5 to +5 points, the average rating was + 2.4 points, so listening was rated as easier with Bonebridge than without hearing aids. The ability to locate the sound source was evaluated by 4 and 0–1 points in one and two respondents, respectively. Examination of spatial hearing: without hearing aid, the ability to locate the sound source was signifi cantly impaired in all the examined. With Bonebridge, with a tolerated deviation of 45°, the success rate of sound source localization was 75–100% in the range of 0–360° in the horizontal plane. Hearing in noise test: the greatest improvement in intelligibility (by 30–100%) was achieved with Bonebridge at SNR –5 dB. Conclusion: Bonebridge is not able to restore binaural hearing in patients with single sided deafness, it is a pseudo-binaural correction. Like other implantable bone conduction systems, Bonebridge is benefi tial for patients with single sided deafness in a variety of listening situations. Using experimental audiological tests, the contribution of Bonebridge to understanding sentences in acoustic noise and improving the ability to locate the sound source was found. However, validation of the results would require a larger number of probands. Keywords: single-sided deafness – BAHD – Bonebridge – bone conduction hearing implant – hearing in noise – directional hearing test

Long-Term, Multicenter Results With the First Transcutaneous Bone Conduction Implant.

Investigation of long-term safety and performance of an active, transcutaneous bone conduction implant in adults and children up to 36 months post-implantation. Prospective, single-subject repeated-measures design. Otolaryngology departments of eight German and Austrian hospitals.∗†‡§||¶#∗∗†† Affiliations listed above that did not participate in the study.‡‡§§||||¶¶. Fifty seven German-speaking patients (49 adults and eight children) suffering from conductive or mixed hearing loss, with an upper bone conduction threshold limit of 45 dB HL at frequencies between 500 and 3000 Hz. Implantation of the Bonebridge transcutaneous bone conduction hearing implant (tBCI). Patients' audiometric pure tone averages (PTA4) (0.5, 1, 2, 4 kHz) thresholds (air conduction, bone conduction, and sound field) and speech perception (word recognition scores [WRS] and speech reception thresholds [SRT50%]) were tested preoperatively and up to 36 months postoperatively. Patients were also monitored for adverse events and administered quality-of-life questionnaires. Speech perception (WRS: pre-op: 17.60%, initial activation [IA]: 74.23%, 3M: 83.65%, 12M: 83.46%, 24M: 84.23%, 36M: 84.42%; SRT50%: pre-op: 65.56 dB SPL, IA: 47.67 dB SPL, 3M: 42.61 dB SPL, 12M: 41.11 dB SPL, 24M: 41.74 dB SPL, 36M: 42.43 dB SPL) and sound field thresholds (pre-op: 57.66 dB HL, IA: 33.82 dB HL, 3M: 29.86 dB HL, 12M: 28.40 dB HL, 24M: 28.22 dB HL, 36M: 28.52 dB HL) improved significantly at all aided postoperative visits. Air and bone conduction thresholds showed no significant changes, confirming preservation of patients' residual unaided hearing. All adverse events were resolved by the end of the study. Safety and performance of the tBCI was demonstrated in children and adults 36 months postoperatively.

Instant auditory benefit of an adhesive BCHD on children with bilateral congenital microtia

Bilateral congenital microtia commonly leads to mild-to-severe conductive hearing loss (CHL), which significantly affects daily communication, causing developmental retardation of speech, poor learning achievement and mental diseases [1]. Bone conduction hearing devices (BCHDs), wearable or implanted, are widely used to restore their hearing ability [2]. Most wearable BCHDs are attached to the skin (mastoid or forehead) with a softband, steel-spring headband, or other fixation types, causing a static pressure [3]. This pressure leads to discomfort, skin reactions and pains for long-term use. The pressure problem also exists in implantable bone conduction systems via magnets (such as BAHA attract and Sophono) [4]. ADHEAR is a pressure-free wearable BCHD, with an adhesive adapter to ensure fixation. The auditory benefit of ADHEAR has already been estimated for bilateral or unilateral CHL in both adults [5] and children [6]. However, the data for children with congenital microtia is still needed.

Adverse events associated with Bonebridge and Osia bone conduction implant devices

PurposeActive transcutaneous Bone Conduction Implants (BCIs) are relatively new to the market and may offer improved outcomes while reducing skin-related complications associated with previous models. The purpose of this study is to examine medical device reports (MDRs) submitted to the Food and Drug Administration's (FDA) Manufacturer and User Device Facility Experience (MAUDE) database to identify adverse events with the active, transcutaneous BCIs, Bonebridge and Osia. MethodsA search of the FDA MAUDE database was conducted using product code “PFO” (for Active Implantable Bone Conduction Hearing System), brand names “Bonebridge” and “Osia.” Data was collected on device malfunction, patient injury, inciting events, and subsequent interventions between July 1, 2018 and November 1, 2020. ResultsThe search query yielded 83 reports that met inclusion criteria, 56 regarding Bonebridge and 27 regarding Osia. A total of 91 adverse events were reported, including 45 device malfunctions and 46 patient injuries. Of all adverse events reported for Bonebridge, 15 (26.3%, 15/57) documented patient injuries, while the majority (73.7%, 42/57) documented device malfunctions. Of all adverse events reported for Osia, 3 (8.8%, 3/34) were reported concerning malfunctions, while 31 (91.2%, 31/34) were reported for patient injuries. The most commonly reported adverse events included lack of conduction or hearing (n = 26, 28.6%), infection (n = 14, 15.4%), and intermittent or reduced conduction or hearing (n = 12, 13.2%). From the MAUDE database reported adverse events and the total number of Osia implants given to us from Cochlear over this 28 month period, we estimate patient injuries to occur in roughly 2.1% of patients. ConclusionThere are limitations to the database which make systemic analysis challenging. This study suggests that patients with transcutaneous, active BCIs may be experiencing fewer soft tissue injuries, but similar device malfunctions as those with previous models.

An Assembly Quality Inspection System for Bone Conduction Implant Transducers

We designed and implemented a two-axis measurement system to inspect the assembly quality condition of a bone conduction implant (BCI) transducer. The system consists of a laser Doppler vibrometer (LDV), XY manual stage, and two digital scale calipers capable of displaying a position coordinate system. To measure the vibration of the cantilever constituting the transducer vibrational membrane, an XY coordinate system was obtained using FEA software. Based on the derived XY coordinate system, the cantilever vibration displacement of the vibrational membrane was measured for each coordinate using the LDV at 0.5, 0.9, and 2 kHz. To visualize the measured area, we developed a Matlab-based application and then visualized the motion of the cantilever. The alignment and misalignment models of the vibrational membrane and permanent magnet were designed using finite element analysis (FEA) software, and the measured cantilever motions of the vibrational membrane were then compared. Finally, to numerically compare the vibration magnitude of the cantilever, the standard deviation was calculated based on the displacement of each edge of the cantilever. The fabricated BCI transducer had a higher standard deviation (3.5 times at 0.5 kHz, 2.3 times at 0.9 kHz) than the ideally aligned FEA model, but the standard deviation was about eight times lower (at 0.5 and 0.9 kHz) than that of the misaligned case. The results of the numerical comparison indicated that the manufactured BCI transducer was very well assembled.

Current and Future Trends in Bone Conduction Implants

Current and Future Trends in Bone Conduction Implants

이식형 골전도 보청기 무선 데이터 전송을 위한 근거리 자기 유도 기술의 무선 링크 최적화에 대한 연구

이식형 골전도 보청기 무선 데이터 전송을 위한 근거리 자기 유도 기술의 무선 링크 최적화에 대한 연구

Assessment of Temporal Bone Thickness for Implantation of a New Active Bone-Conduction Transducer.

To investigate the minimum bone thickness in adults and children in the area of the skull affected by implantation of a new bone conduction device in patients without known medical history that indicates anatomical malformations. Retrospective, non-interventional study on computer tomography (CT) scans on file at a university medical center. A digital model of the new bone conduction implant was virtually implanted in 3D reconstructions of temporal bones based on 197 CT scans, 132 from adults and 65 from children (evenly distributed in five different age groups). The bone thickness was measured in a total of 11 designated positions; five measurement points for the transducer (recess area), and six for the fixation screws, corresponding to three different positions for the fixation band holding the implant in place (screw area). The minimum bone thickness in the combined recess and screw area for adults was 5.55 ± 1.46 mm, with a 95% CI of 5.30 to 5.80 mm. For children, the thickness was 4.34 ± 2.29 mm (95% CI: 3.77-4.91 mm), increasing from 1.92 mm (0-4 yr) to 6.41 mm (12-14 yr). For all ages, the bone in the recess area was generally thicker compared with the screw area.With an implantation depth of 3 mm the transducer fitted in all of the adult temporal bones (100%) and 99.2% (131/132) of the adults had a bone thickness of at least 2.7 mm in all six measured screw positions. In all children from the age of 5 the transducer fitted at an implantation depth of 3 mm, and in all children from the age of 9, the fixation screws fitted at a depth of 2.7 mm. In all CT scans except for a 6-month-old child the new bone conduction device could be implanted in at least one of the fixation band positions analyzed. In adults and many children without known medical history that indicates anatomical malformations, the average minimum bone thickness was thicker than both the maximum transducer depth of 3 mm and the 2.7 mm bone involvement of the osseointegrating fixation screws. The results indicate implant fit of the new bone conduction implant in all adult patients. The risks of compromising the sigmoid sinus and the dura as considered with larger implants are thus significantly reduced. Preoperative planning with CT would still be recommended for children below 9 years old.

Clinical effect of an active transcutaneous bone-conduction implant on tinnitus in patients with ipsilateral sensorineural hearing loss

ObjectivesThis study investigated the effect of an active transcutaneous bone conduction implant (BoneBridgeⓇ) in the management of tinnitus in patients with unilateral sensorineural hearing loss. MethodsFrom October 2016 to July 2018, 15 patients with unilateral tinnitus accompanied by ipsilateral sensorineural hearing loss received BoneBridgeⓇ implants. Pure-tone average, tinnitus handicap inventory (THI), and a visual analogue scale (VAS) for awareness, loudness, and annoyance were measured before and 6 months after surgery. We defined improvement as a reduction of more than 20% between preoperative and postoperative VAS and THI scores, and changes in the THI of over 7 points were also assessed. ResultsMean THI scores before surgery (72.8 ± 16.1) had significantly improved by 6 months postoperatively (50.9 ± 18.9) (p = 0.003). VAS scores for loudness and annoyance also statistically significantly improved (p = 0.011 and 0.002). The amount of functional hearing gain correlated with changes in VAS scores for annoyance. This correlation was stronger with the improvement of high frequency hearing. ConclusionBoneBridgeⓇ is beneficial in patients with tinnitus accompanied by sensorineural hearing loss. This finding can help select patients who will benefit most from bone conduction implants.

MRI after Bonebridge implantation: a comparison of two implant generations.

Analysis of head magnetic resonance images (MRI) of patients with active bone conduction implants (BCIs) is challenging. Currently, there are two generations of the transcutaneous Bonebridge system (BCI601 and BCI602), the main difference between them being the transducer design and thickness. The aim was to compare the effect of transducer placement and artifact reduction sequences on legibility of MRI scans. Four Thiel-fixed human head specimens were used: BCI601 was implanted in sinodural and middle fossa placement, and BCI602 in middle fossa and retrosigmoid approach. Images were obtained with a Signa® 1.5T MR. A metal artifact reduction sequence known as MAVRIC (multiacquisition variable-resonance image combination) was used. Each specimen was scanned using standard axial T2 SE and compared with axial MAVRIC artifact reduction sequences. Qualitatively, limits of the artifact produced by the implant were better defined with MAVRIC than with standard T2 sequences. Assessment of contralateral internal auditory canal (IAC) was possible in all cases. Placement of the BCI602 in the middle fossa allowed the view of the ipsilateral IAC using MAVRIC sequence. Quantitatively, the artifact was reduced with MAVRIC sequence from 6.3 to 59.7%, depending on the position of implant and model; the middle fossa placement and the BCI602 being those generating shorter artifact radio. Artifact optimized sequences as MAVRIC reduce the artifact caused by the Bonebridge system. The middle fossa approach allows a better visualization of IAC canal in the ipsilateral ear with both implant versions, but the effect is more prominent with the BCI602.

The Mechanical Impedance of the Human Skull via Direct Bone Conduction Implants.

PurposeThe mechanical skull impedance is used in the design of direct bone drive hearing systems. This impedance is also important for the design of skull simulators used in manufacturing, service, and fitting procedures of such devices.Patients and MethodsThe skull impedance was measured in 45 patients (25 female and 20 male) who were using percutaneous bone conduction implants (Ponto system or Baha system). Patients were recruited as a consecutive prospective case series and having an average age of 55.4 years (range 18–80 years). Seven patients were treated in Gothenburg, Sweden, and 38 patients in Edmonton, Canada. An impedance head (B&K 8001), driven by an excitation transducer with emphasized low-frequency response, was used to measure the mechanical point impedance with a swept sine from 100 to 10k Hz.Results and DiscussionThe skull impedance was found to have an anti-resonance of approximately 150 Hz, with a median maximum magnitude of 4500 mechanical ohms. Below this anti-resonance, the mechanical impedance was mainly mass-controlled corresponding to an effective skull mass of 2.5 kg at 100 Hz with substantial damping from neck and shoulder. Above the anti-resonance and up to 4 kHz, the impedance was stiffness-controlled, with a total compliance of approximately 450n m/N with a small amount of damping. At frequencies above 4 kHz, the skull impedance becomes gradually mass-controlled originating from the mass of the osseointegrated implant and adjacent bone. No significant differences related to gender or skull abnormalities were seen, just a slight dependence on age and major ear surgeries. The variability of the mechanical impedance among patients was not found to have any clinical importance.ConclusionThe mechanical skull impedance of percutaneous implants was found to confirm previous studies and can be used for optimizing the design and test procedures of direct bone drive hearing implants.

Bone conduction implants.

To discuss the different types of bone conduction implants available today and describe the types of hearing loss that could benefit from bone conduction implants. Bone conduction implants have been used successfully for over two decades. However, there have been barriers to their use because of skin complications and limited high-frequency hearing gains. Recently developed technologies, such as active bone conduction implants may overcome some of these limitations, potentially opening the door for improved aided benefit and increased patient satisfaction from bone conduction amplification. A variety of bone conduction implants currently exist, with suitable amplification options available for many different types and severities of hearing loss and patient preferences.

Efficacy of Implantable Bone Conduction Hearing Aids in Single-Sided Deafness

As the technology advances and bone conduction implant (BCI) use increases, implantable bone conduction hearing aids are regarded as a treatment method for single-sided deafness (SSD) and their efficacy on SSD must be discussed. Therefore, we organized the problems of SSD and types of implantable bone conduction hearing aids and explained their effectiveness in the treatment of SSD in terms of changes in 1) speech recognition in a noisy environment, 2) sound localization, 3) subjective satisfaction as assessed by questionnaire, and 4) tinnitus. Although bone conduction hearing aids do not significantly improve localization ability in SSD, they increase the ability to listen under noise, increasing subjective satisfaction. Tinnitus improvement was also reported. The active forms of BCI like MED-EL BONEBRIDGE®2 and Cochlear Osia®2 have been developed well. Based on these technological developments and effects, bone conduction hearing aids would be a good option for treatment option of SSD.

The evaluation of a surgery and the short-term benefits of a new active bone conduction hearing implant - the Osia®

IntroductionModern medicine offers a wide spectrum of different hearing devices, and bone conduction implants can be found among them. ObjectiveThe presentation of the outcomes of the implantation of a new active bone conduction hearing implant – the Osia®, and its comparison with the well-known passive transcutaneous system – the Baha® Attract. MethodsEight adult patients with bilateral mixed hearing loss were randomly divided into two groups. Group 1 was implanted with the Osia®, and group 2 was implanted with the Baha® Attract. The details of the surgery were analyzed, along with the functional and audiological results. ResultsIn all the cases, the surgery was successful, and the healing uneventful. In both groups, it was observed that pure tone audiometry and speech audiometry in free field improved significantly after the implantation (mean gain in pure tone audiometry for the Osia group 42.8 dB SPL and for the Baha group 38.8 dB SPL). In the Osia group, the results after the surgery were much better than with the Baha® 5 Power processor on the Softband. The patients implanted with the Osia® evaluated the quality of their hearing as being superior to those implanted with the Baha® Attract. There was an evident improvement in the abbreviated profile of hearing aid benefit questionnaire and in the speech, spatial and qualities of hearing scale for both systems. In the abbreviated profile of hearing aid benefit, changes were more evident in the Osia group (in global score 49% vs. 37.2%). ConclusionImplantation of the Osia® is an effective treatment option for the patients with bilateral mixed hearing loss. The surgery is safe but more complex and time-consuming than the Baha® Attract implantation. The preliminary audiological results as well as the overall quality of life indicate that the Osia® is a better solution than the Baha® Attract. However, future studies should be carried out to make further observations in a larger group of patients, and with longer follow-up.

Three-Year Follow-Up with the Bone Conduction Implant

Background: The bone conduction implant (BCI) is an active transcutaneous bone conduction device where the transducer has direct contact to the bone, and the skin is intact. Sixteen patients have been implanted with the BCI with a planned follow-up of 5 years. This study reports on hearing, quality of life, and objective measures up to 36 months of follow-up in 10 patients. Method: Repeated measures were performed at fitting and after 1, 3, 6, 12, and 36 months including sound field warble tone thresholds, speech recognition thresholds in quiet, speech recognition score in noise, and speech-to-noise thresholds for 50% correct words with adaptive noise. Three quality of life questionnaires were used to capture the benefit from the intervention, appreciation from different listening situations, and the ability to interact with other people when using the BCI. The results were compared to the unaided situation and a Ponto Pro Power on a soft band. The implant functionality was measured by nasal sound pressure, and the retention force from the audio processor against the skin was measured using a specially designed audio processor and a force gauge. Results: Audiometry and quality of life questionnaires using the BCI or the Ponto Pro Power on a soft band were significantly improved compared to the unaided situation and the results were statistically supported. There was generally no significant difference between the two devices. The nasal sound pressure remained stable over the study period and the force on the skin from the audio processor was 0.71 ± 0.22 N (mean ± 1 SD). Conclusion: The BCI improves the hearing ability for tones and speech perception in quiet and in noise for the indicated patients. The results are stable over a 3-year period, and the patients subjectively report a beneficial experience from using the BCI. The transducer performance and contact to the bone is unchanged over time, and the skin area under the audio processor remains without complications during the 3-year follow-up.

Active Transcutaneous Bone Conduction Implant: Audiometric Outcomes Following a Novel Middle Fossa Approach With Self-Drilling Screws.

To present surgical and audiometric outcomes of patients implanted with an active transcutaneous bone conduction implant following the novel middle fossa surgical approach with self-drilling screws. Retrospective review. Tertiary care center. Thirty-seven adults with either conductive or mixed hearing loss that met indications for an active transcutaneous bone conduction implant were consecutively implanted from April, 2013 to May, 2018. Unilateral middle fossa implantation of an active transcutaneous bone conduction implant. Patient charts were reviewed for surgical outcomes and complications over the 6-year period. Preoperative air conduction, preoperative bone conduction, and 3-month postoperative aided thresholds were recorded. Speech perception was assessed using CNC words and AzBio sentences. Pure-tone averages (PTAs; measured at 0.5, 1.0, 2.0 and 3.0 kHz), air-bone gap, and functional gain were calculated. Mean air conduction and bone conduction PTAs (±standard deviation) of the implanted ear were 66.8 dB (±14.9 dB) and 21.9 dB (±14.0 dB), respectively. Mean aided PTA was 26.5 dB (± 8.5 dB). The average functional gain was 40.3 dB (±19.0 dB). Favorable speech perception outcomes were observed. No complications or instances of revision surgery were reported, with a mean follow-up time of 32 months (range, 9-71 mo). This is the first paper to describe outcomes of patients implanted with an active transcutaneous bone conduction implant via the middle fossa with self-drilling screws. Favorable surgical outcomes were observed with a follow-up of up to 6 years.

Audiological outcome measures with the BONEBRIDGE transcutaneous bone conduction hearing implant: impact of noise, reverberation and signal processing features

Objective: To assess the performance of an active transcutaneous implantable-bone conduction device (TI-BCD), and to evaluate the benefit of device digital signal processing (DSP) features in challenging listening environments.Design: Participants were tested at 1- and 3-month post-activation of the TI-BCD. At each session, aided and unaided phoneme perception was assessed using the Ling-6 test. Speech reception thresholds (SRTs) and quality ratings of speech and music samples were collected in noisy and reverberant environments, with and without the DSP features. Self-assessment of the device performance was obtained using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire.Study sample: Six adults with conductive or mixed hearing loss.Results: Average SRTs were 2.9 and 12.3 dB in low and high reverberation environments, respectively, which improved to −1.7 and 8.7 dB, respectively with the DSP features. In addition, speech quality ratings improved by 23 points with the DSP features when averaged across all environmental conditions. Improvement scores on APHAB scales revealed a statistically significant aided benefit.Conclusions: Noise and reverberation significantly impacted speech recognition performance and perceived sound quality. DSP features (directional microphone processing and adaptive noise reduction) significantly enhanced subjects’ performance in these challenging listening environments.

A Precision Driver Device for Intraoperative Stimulation of a Bone Conduction Implant

Semi-implantable bone conduction implants (BCI) and active middle ear implants (AMEI) for patients with sensorineural, conductive or mixed hearing loss commonly use an amplitude modulation technology to transmit power and sound signals from an external audio processor to the implant. In patients, the distance dependence of the signal amplitude is of minor importance as the skin thickness is constant and only varies between 3–7 mm. In this range, critical coupling transmission technique sufficiently reduces the variability in amplitude, but fails to provide well-defined amplitudes in many research and clinical applications such as intraoperative integrity tests where the distance range is exceeded by using sterile covers. Here we used the BCI Bonebridge (BB, Med-El, Austria) as an example to develop and demonstrate a system that synthesizes the transmission signal, determines the distance between the transmitter and the receiver implant coil and compensates transmission losses. When compared to an external audio processor (AP304) on an artificial mastoid, our system mainly decreased amplitude variability from over 11 dB to less than 3 dB for audio frequencies (0.1–10 kHz) at distances up to 15 mm, making it adequate for intraoperative and audiometric tests.

A Comparison of Intracochlear Pressures During Ipsilateral and Contralateral Stimulation With a Bone Conduction Implant.

To compare contralateral to ipsilateral stimulation with percutaneous and transcutaneous bone conduction implants. Bone conduction implants (BCIs) effectively treat conductive and mixed hearing losses. In some cases, such as in single-sided deafness, the BCI is implanted contralateral to the remaining healthy ear in an attempt to restore some of the benefits provided by binaural hearing. While the benefit of contralateral stimulation has been shown in at least some patients, it is not clear what cues or mechanisms contribute to this function. Previous studies have investigated the motion of the ossicular chain, skull, and round window in response to bone vibration. Here, we extend those reports by reporting simultaneous measurements of cochlear promontory velocity and intracochlear pressures during bone conduction stimulation with two common BCI attachments, and directly compare ipsilateral to contralateral stimulation. Fresh-frozen whole human heads were prepared bilaterally with mastoidectomies. Intracochlear pressure (PIC) in the scala vestibuli (PSV) and tympani (PST) was measured with fiber optic pressure probes concurrently with cochlear promontory velocity (VProm) via laser Doppler vibrometry during stimulation provided with a closed-field loudspeaker or a BCI. Stimuli were pure tones between 120 and 10,240 Hz, and response magnitudes and phases for PIC and VProm were measured for air and bone conducted sound presentation. Contralateral stimulation produced lower response magnitudes and longer delays than ipsilateral in all measures, particularly for high-frequency stimulation. Contralateral response magnitudes were lower than ipsilateral response magnitudes by up to 10 to 15 dB above ~2 kHz for a skin-penetrating abutment, which increased to 25 to 30 dB and extended to lower frequencies when applied with a transcutaneous (skin drive) attachment. Transcranial attenuation and delay suggest that ipsilateral stimulation will be dominant for frequencies over ~1 kHz, and that complex phase interactions will occur during bilateral or bimodal stimulation. These effects indicate a mechanism by which bilateral users could gain some bilateral advantage.