Oticon Medical Research Articles

Evaluation of an abutment-level superpower sound processor for bone-anchored hearing.

Performance of an abutment-level superpower sound processor for bone-anchored hearing, the Ponto 3 SuperPower from Oticon Medical (BCD2), was compared to an earlier model from Oticon Medical (BCD1). A comparative study in which each patient serves as its own control. Tertiary clinic. Eighteen experienced BCD1 users with profound mixed hearing loss. Speech reception thresholds in noise; APHAB and SSQ questionnaires. In a group of 18 patients with severe mixed hearing loss, the performance of a recently introduced bone conduction device (BCD2) is evaluated relative to that of an earlier model (BCD1). Speech reception thresholds for the sentence-in-noise test in the speech and noise frontal condition are not significantly different (P>.05) for BCD1 and BCD2. Speech reception thresholds for frontal speech and three identical noise sources are 1.7 dB lower for BCD2 than for BCD1 (P<.05). With the APHAB questionnaire, the score for background noise is significantly lower (P<.01), that is more favourable, for BCD2 than for BCD1 with an effect size of 0.91. The APHAB domain scores for ease-of-communication, reverberation and aversiveness of loud sounds are not significantly different for both devices (P>.05). Scores for the speech, spatial and quality of hearing domains of the SSQ questionnaire are significantly higher (P<.01), that is more favourable, for BCD2 than for BCD1 with effect sizes of 1.22, 0.71 and 1.05, respectively. Scores for the SSQ-factors "speech understanding," "spatial," "clarity, separation and identification" and "listening effort and concentration" were all significantly higher (P<.05) for BCD2 than for BCD1, with effect sizes of 1.28, 0.64, 0.98 and 0.78, respectively. On a proprietary questionnaire, 16 patients indicate a preference for BCD2 over BCD1 for conversations in a small group and two patients have no preference for either device. In a large group, one patient prefers BCD1, six patients have no preference, and eleven patients prefer BCD2. When listening to music, all patients prefer BCD2 over BCD1, with a strong preference for BCD2 for seven patients. When asked for an overall preference, all patients prefer BCD2 over BCD1, with nine patients strongly preferring BCD2. The lower speech reception thresholds in noise with BCD2 relative to BCD1 can be attributed to the "speech omni" directionality mode of BCD2. The combination of an improved directionality for primarily low-level inputs and a higher maximum force output, relevant for mid- and high-level inputs, results in a clear preference for BCD2 over BCD1.

Comparing audiological outcomes between the Bonebridge and bone conduction hearing aid on a hard test band: Our experience in children with atresia and microtia

IntroductionTo compare the audiological results of Bone Conduction Hearing Aid (BCHA) on hard test band and Bonebridge (BB) implant among children with microtia and atresia. MethodsThis is a retrospective review of patients with microtia and atresia who underwent BB implant insertion from September 2014 to February 2017 in Starship Children's Hospital. Preoperative audiological testing using a powered BCHA (Oticon Medical Ponto Pro Power) on a hard test band was used to compare post-operative hearing assessments with the BB. ResultsTen microtia and atresia patients were treated with a BB of whom three were treated bilaterally The children were aged between 5 and 15 and all had moderate to moderately severe conductive hearing loss. For each ear tested and subsequently implanted, BB aided speech scores were equivalent to that obtained by a BCHA. The mean improvement of speech reception threshold level between unaided and BB was statistically significant (p > 0.0001). Subjective questionnaire data indicated that BB implanted patients were performing within the norms of overall listening, both in quiet and in noise. Aided Speech In Noise (SIN) testing values were found to range from 0.8–6.5 for BCHA and 0.2–1.2 for BB and the difference was not statistically significant with a p value of 0.143. ConclusionIn audiologic assessments BB performs comparably to BCHA among children with microtia and atresia.

Comparison of implant stability measurement devices for bone-anchored hearing aid systems

Statement of problemThe success of implants for bone-anchored hearing aids (BAHA) relies on proper osseointegration at the bone-implant interface. Clinical evaluation of implant stability is important in prescribing loading, identifying the risk of failure, and monitoring the long-term health of the implant. PurposeThe purpose of this in vitro study was to evaluate 2 measurement systems for BAHA implant stability: the most commonly used, Osstell implant stability quotient (ISQ), and a newly developed advance system for implant stability testing (ASIST). Material and methodsBAHA implants (Oticon Medical Ponto and Cochlear BAHA Connect systems) were installed in plastic materials with adhesive to simulate implants integrated in bone with varying levels of interface stiffness. Different lengths of BAHA abutments were used with each implant specimen, and stability measurements were obtained with both the Osstell ISQ and the ASIST systems. The measurement systems were evaluated in terms of sensitivity to differences in interface stiffness and the effect of abutment length on the stability measurement. Repeated measures ANOVA followed by post hoc t tests were used for the comparisons with a Bonferroni adjusted alpha value of .05/15 = .003 to control for potential type 1 errors. ResultsChanging the abutment length of a single implant installation had minimal effect on the ASIST stability coefficient, whereas large variations were observed in the Osstell implant stability quotient (ISQ). The Osstell showed a clear relationship of decreasing ISQ with increasing abutment length for both the Oticon Medical and the Cochlear implant systems. Both the ASIST and the Osstell were found to be sensitive to changes in interface properties, with the ASIST being more sensitive to these changes. ConclusionsThe ASIST system is more sensitive to changes in interface properties and shows smaller variation because of changes in abutment length than the Osstell ISQ system.

Minimally Invasive Ponto Surgery compared to the linear incision technique without soft tissue reduction for bone conduction hearing implants: study protocol for a randomized controlled trial

BackgroundOver the last years, less invasive surgical techniques with soft tissue preservation for bone conduction hearing implants (BCHI) have been introduced such as the linear incision technique combined with a punch. Results using this technique seem favorable in terms of rate of peri-abutment dermatitis (PAD), esthetics, and preservation of skin sensibility. Recently, a new standardized surgical technique for BCHI placement, the Minimally Invasive Ponto Surgery (MIPS) technique has been developed by Oticon Medical AB (Askim, Sweden). This technique aims to standardize surgery by using a novel surgical instrumentation kit and minimize soft tissue trauma.MethodsA multicenter randomized controlled trial is designed to compare the MIPS technique to the linear incision technique with soft tissue preservation. The primary investigation center is Maastricht University Medical Center. Sixty-two participants will be included with a 2-year follow-up period. Parameters are introduced to quantify factors such as loss of skin sensibility, dehiscence of the skin next to the abutment, skin overgrowth, and cosmetic results. A new type of sampling method is incorporated to aid in the estimation of complications. To gain further understanding of PAD, swabs and skin biopsies are collected during follow-up visits for evaluation of the bacterial profile and inflammatory cytokine expression.The primary objective of the study is to compare the incidence of PAD during the first 3 months after BCHI placement. Secondary objectives include the assessment of parameters related to surgery, wound healing, pain, loss of sensibility of the skin around the implant, implant extrusion rate, implant stability measurements, dehiscence of the skin next to the abutment, and esthetic appeal. Tertiary objectives include assessment of other factors related to PAD and a health economic evaluation.DiscussionThis is the first trial to compare the recently developed MIPS technique to the linear incision technique with soft tissue preservation for BCHI surgery. Newly introduced parameters and sampling method will aid in the prediction of results and complications after BCHI placement.Trial registrationRegistered at the CCMO register in the Netherlands on 24 November 2014: NL50072.068.14. Retrospectively registered on 21 April 2015 at ClinicalTrials.gov: NCT02438618. This trial is sponsored by Oticon Medical AB.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1662-0) contains supplementary material, which is available to authorized users.

Advanced System for Implant Stability Testing (ASIST)

This study presents the Advanced System for Implant Stability Testing (ASIST) which provides a non-invasive, quantitative measure of the stability of percutaneous implants used for craniofacial rehabilitation such as bone anchored hearing aids or dental implants. The ASIST uses an impact technique coupled with an analytical model which allows the measure to be independent of the system components. This paper presents a laboratory evaluation of the ASIST for the Oticon Medical Ponto and the Cochlear Baha Connect bone anchored hearing aid (BAHA) systems. There is minimal effect of abutment length on the ASIST Stability Coefficient (ASC) value, indicating that the method is able to isolate the interface properties from the overall system and the measurement is independent of attached components. Additionally, the ASIST was able to detect differences between different implant installations suggesting that it may be sensitive to changes in interface stiffness.

Perception in noise with the Digisonic SP cochlear implant: Clinical trial of Saphyr processor's upgraded signal processing

ObjectivesIn 2012, Bergeron et al. presented the outcomes of a study where speech recognition abilities were compared between the four major cochlear implant manufacturers from comparable samples assessed with the same protocols. At this moment, results showed no significant difference in speech perception between devices in quiet and in different noise conditions. But, while most devices appeared only slightly disturbed by the presence of a low to moderate noise level, the Oticon Medical device appeared significantly more sensitive to a degraded environment. In 2013, the signal processing strategy of this device has been upgraded. This study proposes to assess the benefits derived from this upgrade. Materials and methodsThe study involves eighteen adults; most were also part of the 2012 study. All were tested before the implementation of the new signal processing strategy, immediately following the implementation of the strategy and after a one-month experience with the strategy. The same speech recognition test and conditions used in the 2012 study were applied, that is the HINT in quiet and in noise at +10, +5 and 0dB signal to noise ratio. Subjective impressions on the upgraded strategy were also gathered. ResultsThe study evidences similar performance for speech perception in quiet, but significant improvements for speech perception in noise with the new processing strategy compared to the original. Subjective reports confirm this improvement in more challenging conditions. ConclusionThe high sensitivity to a degraded environment observed with the original Oticon Medical device has been significantly reduced by the introduction of more efficient noise reduction processing strategies.

A Cochlear Implant Performance Prognostic Test Based on Electrical Field Interactions Evaluated by eABR (Electrical Auditory Brainstem Responses)

BackgroundCochlear implants (CIs) are neural prostheses that have been used routinely in the clinic over the past 25 years. They allow children who were born profoundly deaf, as well as adults affected by hearing loss for whom conventional hearing aids are insufficient, to attain a functional level of hearing. The “modern” CI (i.e., a multi-electrode implant using sequential coding strategies) has yielded good speech comprehension outcomes (recognition level for monosyllabic words about 50% to 60%, and sentence comprehension close to 90%). These good average results however hide a very important interindividual variability as scores in a given patients’ population often vary from 5 to 95% in comparable testing conditions. Our aim was to develop a prognostic model for patients with unilateral CI. A novel method of objectively measuring electrical and neuronal interactions using electrical auditory brainstem responses (eABRs) is proposed.Methods and FindingsThe method consists of two measurements: 1) eABR measurements with stimulation by a single electrode at 70% of the dynamic range (four electrodes distributed within the cochlea were tested), followed by a summation of these four eABRs; 2) Measurement of a single eABR with stimulation from all four electrodes at 70% of the dynamic range. A comparison of the eABRs obtained by these two measurements, defined as the monaural interaction component (MIC), indicated electrical and neural interactions between the stimulation channels.Speech recognition performance without lip reading was measured for each patient using a logatome test (64 "vowel-consonant-vowel"; VCV; by forced choice of 1 out of 16). eABRs were measured in 16 CI patients (CIs with 20 electrodes, Digisonic SP; Oticon Medical ®, Vallauris, France).Significant correlations were found between speech recognition performance and the ratio of the amplitude of the V wave of the eABRs obtained with the two measurements (Pearson's linear regression model, parametric correlation: r2 = 0.26, p<0.05).ConclusionsThis prognostic model allowed a substantial amount of the interindividual variance in speech recognition scores to be explained. The present study used measurements of electrical and neuronal interactions by eABR to assess patients' bio-electric capacity to use multiple information channels supplied by the implant. This type of prognostic information may be valuable in several ways. On the patient level, it allows customizing of individual treatments.ClinicalTrials.gov Identifier: NCT01805167

Enhancing osseointegration by site-specific laser modification of titanium implants: comparative and correlative analyses of different parameters of bone-implant integration

Enhancing osseointegration by site-specific laser modification of titanium implants: comparative and correlative analyses of different parameters of bone-implant integration

A Binaural CI Research Platform for Oticon Medical SP/XP Implants Enabling ITD/ILD and Variable Rate Processing.

We present the first portable, binaural, real-time research platform compatible with Oticon Medical SP and XP generation cochlear implants. The platform consists of (a) a pair of behind-the-ear devices, each containing front and rear calibrated microphones, (b) a four-channel USB analog-to-digital converter, (c) real-time PC-based sound processing software called the Master Hearing Aid, and (d) USB-connected hardware and output coils capable of driving two implants simultaneously. The platform is capable of processing signals from the four microphones simultaneously and producing synchronized binaural cochlear implant outputs that drive two (bilaterally implanted) SP or XP implants. Both audio signal preprocessing algorithms (such as binaural beamforming) and novel binaural stimulation strategies (within the implant limitations) can be programmed by researchers. When the whole research platform is combined with Oticon Medical SP implants, interaural electrode timing can be controlled on individual electrodes to within ±1 µs and interaural electrode energy differences can be controlled to within ±2%. Hence, this new platform is particularly well suited to performing experiments related to interaural time differences in combination with interaural level differences in real-time. The platform also supports instantaneously variable stimulation rates and thereby enables investigations such as the effect of changing the stimulation rate on pitch perception. Because the processing can be changed on the fly, researchers can use this platform to study perceptual changes resulting from different processing strategies acutely.

Vibrant Soundbridge and Bone Conduction Hearing Aid in Patients with Bilateral Malformation of External Ear.

Introduction Hearing loss is the most common clinical finding in patients with malformation of the external ear canal. Among the possibilities of treatment, there is the adaptation of hearing aids by bone conduction and the adaptation of implantable hearing aids. Objective To assess speech perception with the use of Vibrant Soundbridge (VBS - MED-EL, Innsbruck, Austria) associated with additional amplification in patients with bilateral craniofacial malformation. Method We evaluated 11 patients with bilateral malformation over 12 years with mixed hearing loss or bilateral conductive. They were using the Softband (Oticon Medical, Sweden) and bone conduction hearing aid in the ear opposite the one with the VSB. We performed the evaluation of speech perception using the Hearing in Noise Test. Results Participants were eight men and three women with a mean of 19.5 years. The signal / noise ratio presented significant results in patients fitted with VSB and bone conduction hearing aid. Conclusion The results of speech perception were significantly better with use of VBS combined with bone conduction hearing aids.

One-Year Follow Up of Auditory Performance in Post-Lingually Deafened Adults Implanted with the Neurelec Digisonic(®) SP/Saphyr(®) Neo Cochlear Implant System.

This study aimed to quantify outcomes in a group of patients who were implanted with an Oticon Medical Neurelec (Vallauris, France) cochlear implant system, the Digisonic® SP/Saphyr® Neo. Ten participants took part in this preliminary study. Their speech perception capacities were evaluated at 3, 6, and 12-months after cochlear implant activation and compared to pre-implantation scores and to scores observed with former versions of the sound processor. Compared to former versions of the sound processor, patients using the Saphyr® Neo processor obtained better speech perception scores for sentences in silence at each tests session (3 months: 79%, 6 months: 82% and 12 months: 94%) compared to Digisonic® users (respectively: 58%, 69% and 75%) and Convex sound processor users (resp. 39%, 59% and 51%). These observations confirm that the technological improvements made in the Saphyr® Neo sound processor coupled with the Digisonic® implant, provided quantifiable benefits in speech perception in Quiet compared to former versions of the processor Convex and Digisonic® SP.

Initial experience of a rapid-insertion bone-anchored hearing system: series of 20 consecutive implants.

Objective: The loading of bone-anchored hearing system sound processors usually occurs two to three months after surgical implant. This study examined a new bone-anchored hearing system coupling mechanism that permits loading at two weeks post-implantation without compromising osseointegration. Methods: Twenty implants were implanted into 15 patients. The interval between operation and time of processor loading was recorded, along with the cause of any delay and any late complications. Results: Two patients were fitted with implants at seven and nine weeks. The delay was a result of administrative errors; the patients reported no skin problems. Of the remaining 17 implants, 8 processors were fitted at 2 weeks, 1 at 3 weeks, 4 at 4 weeks, 3 at 7 weeks and 1 at 8 weeks. For those nine implants fitted later than two weeks, the delay was because of incomplete skin healing. Conclusion: The Oticon Medical Xpress system allowed processor loading at two weeks post-operatively, providing skin healing was adequate. Early loading occurred in approximately half of the patients. All patients were fitted within the two to three months traditionally allowed. Prolonged skin healing time was the main reason for the delayed fitting of sound processors.

Bone Conduction Hearing: Device Auditory Capability to Aid in Device Selection

To obtain identical laboratory measures of 8 (surgical and nonsurgical) bone conduction devices and relate them to clinical function. Each device was measured with a single laboratory system and characterized with descriptive statistics. Laboratory. Seven surgical devices (Intenso, BP110, BP100, and Cordelle [Cochlear, Denver, Colorado]; Ponto Pro and Ponto Pro Power [Oticon Medical, Somerset, New Jersey]; and Alpha 2 [Sophono, Inc, Boulder, Colorado]) and 1 nonsurgical dental device (SoundBite; Sonitus Medical, Inc, San Mateo, California) constituted the independent variables. Measured maximum output and gain parameters were the dependent variables. Maximum output varied across devices in the pure-tone average (PTA; 500-3000 Hz) frequency range (mean, 109.7 dB re 1 µN; range, 98.8-119.2 dB) and in the above-PTA (4000-8000 Hz) frequency range (mean, 102.6 dB re 1 µN; range, 88.99-119.6 dB). Maximum gain varied in the PTA frequency range (mean, 40 dB; range, 29.1-49.1 dB) and was higher in the frequency range above the PTA (mean, 32.0 dB; range, 20.8-46.0 dB). All devices have sufficient maximum output and gain for the PTA frequency range for single-sided deafness (SSD). The devices differed in maximum output and gain for the frequency range above the PTA, a consideration for accommodating presbycusis and optimizing auditory function for SSD. The surgical devices have less maximum output and gain in the above-PTA range than in the PTA range. The nonsurgical dental device had the highest output (up to 30 dB higher) and gain (up to 26 dB higher) in the above-PTA range.

Contemporary hearing rehabilitation options in patients with aural atresia.

Congenital aural atresia is the failure of development of the external auditory canal. It usually occurs in conjunction with microtia, which is the malformation of the auricle due to a failure of development of the external ear. Aural atresia, with or without microtia, may significantly affect the hearing and social life of the patients. It is important for every medical practitioner to be aware of the possible treatment options for hearing rehabilitation in this group of patients. In the era of modern technology, new choices, including Bone-Anchored Hearing Aid (BAHA) (Cochlear Ltd. and Oticon Medical), Vibrant Soundbridge (VSB) (MED-EL, Innsbruck, Austria), and Bonebridge system (BB) (MED-EL, Innsbruck, Austria), provide high-end alternatives to traditional Bone Conduction Hearing Aid and Auditory Canal Reconstruction. All these options have advantages and disadvantages, and they are appropriate for different patients and/or at different ages. This paper aims to provide an overview of the management of hearing rehabilitation in congenital aural atresia patients and a discussion of each treatment option.

The Effectiveness of the Directional Microphone in the Oticon Medical Ponto Pro in Participants with Unilateral Sensorineural Hearing Loss

Current bone anchored hearing solutions (BAHSs) have incorporated automatic adaptive multichannel directional microphones (DMs). Previous fixed single-channel hypercardioid DMs in BAHSs have provided benefit in a diffuse listening environment, but little data are available on the performance of adaptive multichannel DMs in BAHSs for persons with unilateral sensorineural hearing loss (USNHL). The primary goal was to determine if statistically significant differences existed in the mean Reception Threshold for Sentences (RTS in dB) in diffuse uncorrelated restaurant noise between unaided, an omnidirectional microphone (OM), split DM (SDM), and full DM (FDM) in the Oticon Medical Ponto Pro. A second goal was to assess subjective benefit using the Abbreviated Profile of Hearing Aid Benefit (APHAB) comparing the Ponto Pro to the participant's current BAHS, and the Ponto Pro and participant's own BAHS to unaided. The third goal was to compare RTS data of the Ponto Pro to data from an identical study examining Cochlear Americas' Divino. A randomized repeated measures, single blind design was used to measure an RTS for each participant for unaided, OM, SDM, and FDM. Fifteen BAHS users with USNHL were recruited from Washington University in St. Louis and the surrounding area. The Ponto Pro was fit by measuring in-situ bone conduction thresholds and was worn for 4 wk. An RTS was obtained utilizing Hearing in Noise Test (HINT) sentences in uncorrelated restaurant noise from an eight loudspeaker array, and subjective benefit was determined utilizing the APHAB. Analysis of variance (ANOVA) was used to analyze the results of the Ponto Pro HINT and APHAB data, and comparisons between the Ponto Pro and previous Divino data. No statistically significant differences existed in mean RTS between unaided, the Ponto Pro's OM, SDM, or FDM (p = 0.10). The Ponto Pro provided statistically significant benefit for the Background Noise (BN) (p < 0.01) and Reverberation (RV) (p < 0.05) subscales compared to the participant's own BAHS. The Ponto Pro (Ease of Communication [EC] [p < 0.01], BN [p < 0.001], and RV [p < 0.01] subscales) and participant's own BAHS (BN [p < 0.01] and RV [p < 0.01] subscales) overall provided statistically significant benefit compared to unaided. Clinically significant benefit of 5% was present for the Ponto Pro compared to the participant's own BAHS and 10% for the Ponto Pro and the participant's own BAHS compared to unaided. The Ponto Pro's OM (p = 0.05), SDM (p = 0.05), and FDM (p < 0.01) were statistically significantly better than the Divino's OM. No significant differences existed between the Ponto Pro's OM, SDM, and FDM compared to the Divino's DM. No statistically significant differences existed between unaided, OM, SDM, or FDM. Participants preferred the Ponto Pro compared to the participant's own BAHS and the Ponto Pro and participant's own BAHS compared to unaided. The RTS of the Ponto Pro's adaptive multichannel DM was similar to the Divino's fixed hypercardioid DM, but the Ponto Pro's OM was statistically significantly better than the Divino's OM.

Evaluation of a New Powerful Bone-Anchored Hearing System: A Comparison Study

The recent introduction of digital hearing aid technology for bone-conduction devices employing percutaneous stimulation may be beneficial for patients with conductive and mixed hearing loss and single sided deafness. Performance of a recently released sound processor for bone-anchored implants, the Ponto Pro Power from Oticon Medical (bone-conduction device 2 [BCD2]), was compared with that of the Baha Intenso from Cochlear (bone-conduction device 1 [BCD1]). Direct comparison of the subject's own device (BCD1) with the new device (BCD2) was examined in a nonrandomized design. Subjects were initially tested with BCD1. BCD2 was tested after a 4 wk acclimatization period. Eighteen subjects with mixed hearing loss and with at least 4 mo experience with BCD1 completed the study. Mean air-conduction and bone-conduction thresholds averaged across the frequencies of 500, 1000, 2000, and 4000 Hz were 73.9 and 34.2 dB HL, respectively. Performance of the two devices was evaluated objectively by measuring aided free-field thresholds, speech perception in quiet, and speech perception in noise. A subjective evaluation was carried out with the Abbreviated Profile of Hearing Aid Benefit (APHAB) (Cox and Alexander, 1995) and the Speech, Spatial and Qualities of Hearing Scale (SSQ) questionnaire (Gatehouse and Noble, 2004). In addition, user experiences, user satisfaction, and device preference were obtained via proprietary questionnaires. Statistical significance was established with analysis-of-variance (ANOVA) and paired t-statistics with Bonferroni correction. Aided free-field thresholds and speech reception thresholds (SRTs) in quiet were not statistically significantly different for either device (p > 0.05). In contrast, SRTs in noise were 2.0 dB lower (p < 0.001) for BCD2 than for BCD1. APHAB questionnaire scores on all subscales provided statistically significantly greater benefit (p < 0.05) for BCD2 than for BCD1. Also, with the SSQ most items in the speech and sound quality domain were significantly more favorable (p < 0.05) for BCD2 than for BCD1. Finally, all subjects preferred BCD2 over BCD1 with 14 subjects reporting a strong preference and four subjects an average preference for the digital signal processing provided by BCD2 over previous technology provided by BCD1.

THE SYSTEMATIC ERRORS IN TISSUE MODULUS OF MURINE BONES WHEN ESTIMATED FROM THREE-POINT BENDING

This study presents the Advanced System for Implant Stability Testing (ASIST) which provides a non-invasive, quantitative measure of the stability of percutaneous implants used for craniofacial rehabilitation such as bone anchored hearing aids or dental implants. The ASIST uses an impact technique coupled with an analytical model which allows the measure to be independent of the system components. This paper presents a laboratory evaluation of the ASIST for the Oticon Medical Ponto and the Cochlear Baha Connect bone anchored hearing aid (BAHA) systems. There is minimal effect of abutment length on the ASIST Stability Coefficient (ASC) value, indicating that the method is able to isolate the interface properties from the overall system and the measurement is independent of attached components. Additionally, the ASIST was able to detect differences between different implant installations suggesting that it may be sensitive to changes in interface stiffness.