Bone Conduction Hearing Aid Research Articles

Influence of stimulation position on the sensitivity for bone conduction hearing aids without skin penetration

Objective: This study explores the influence of stimulation position on bone conduction (BC) hearing sensitivity with a BC transducer attached using a headband. Design: (1) The cochlear promontory motion was measured in cadaver heads using laser Doppler vibrometry while seven different positions around the pinna were stimulated using a bone anchored hearing aid transducer attached using a headband. (2) The BC hearing thresholds were measured in human subjects, with the bone vibrator Radioear B71 attached to the same seven stimulation positions. Study sample: Three cadaver heads and twenty participants. Results: Stimulation on a position superior-anterior to the pinna generated the largest promontory motion and the lowest BC thresholds. Stimulations on the positions superior to the pinna, the mastoid, and posterior-inferior to the pinna showed similar magnitudes of promontory motion and similar levels of BC thresholds. Conclusion: Stimulations on the regions superior to the pinna, the mastoid, and posterior-inferior to the pinna provide stable BC transmission, and are insensitive to small changes of the stimulation position. Therefore it is reliable to use the mastoid to determine BC thresholds in clinical audiometry. However, stimulation on a position superior-anterior to the pinna provides more efficient BC transmission than stimulation on the mastoid.

Hearing in school-aged children with trisomy 21 - results of a longitudinal cohort study in children identified at birth.

To report the prevalence of hearing problems and the hearing sequelae in school-aged children with trisomy 21 in a longitudinal study. All children with trisomy 21 were identified via schools, community-based child development centres, general practitioners, or the universal newborn hearing screen. Audiological data and otorhinolaryngological problems were prospectively entered in to the Audiological Surveillance Programme database from each visit. Retrospective review of the Audiological Surveillance Programme database in the Glasgow area (United Kingdom) of all children reviewed between 2004 and 2012. All pre-teenaged children with trisomy 21 of school age (aged 5-12 years old). Hearing thresholds, aetiology of hearing loss and management of hearing loss was determined for the cohort of children. A total of 102 children were included. Fifty-four had normal hearing. Twenty-six had fluctuating otitis media with effusion; five had hearing in normal limits, six were managed with hearing aids, fourteen were managed conservatively, and one had ventilation tube insertion. Fifteen had persistent otitis media with effusion; four had ventilation tube insertion; and nine were managed with hearing aids. Seven had mixed hearing loss with four required hearing aids. Otitis media with effusion was the commonest cause of hearing impairment; effusions may fluctuate through the pre-teenaged years, and thus, hearing aids are beneficial. Ventilation tube insertion and bone-conducting hearing aids were useful when ear-level hearing aids were not tolerated. Mixed hearing loss occurred in later years as sensorineural hearing loss developed on a background of otitis media with effusion.

Intracranial Pressure and Promontory Vibration With Soft Tissue Stimulation in Cadaveric Human Whole Heads.

Intracranial pressure and skull vibrations are correlated and depend on the stimulation position and frequency. A hearing sensation can be elicited by vibratory stimulation on the skin covered skull, or by stimulation on soft tissue such as the neck. It is not fully understood whether different stimulation sites induce the skull vibrations responsible for the perception or whether other transmission pathways are dominant. The aim of this study was to assess the correlation between intracranial pressure and skull vibration measured on the promontory for stimulation to different sites on the head. Measurements were performed on four human cadaver heads. A bone conduction hearing aid was held in place with a 5-Newton steel headband at four locations (mastoid, forehead, eye, and neck). While stimulating in the frequency range of 0.3 to 10 kHz, acceleration of the cochlear promontory was measured with a Laser Doppler Vibrometer, and intracranial pressure at the center of the head with a hydrophone. Promontory acceleration and intracranial pressure was measurable for all stimulation sites. The ratios were comparable between all stimulation sites for frequencies below 2 kHz. These findings indicate that both promontory acceleration and intracranial pressure are involved for stimulation on the sites investigated. The transmission pathway of sound energy is comparable for the four stimulation sites.

1F42 埋め込み型骨導補聴器用振動子の駆動方法の検討

1F42 埋め込み型骨導補聴器用振動子の駆動方法の検討

Traceable calibration of impedance heads and artificial mastoids

Artificial mastoids are devices which simulate the mechanical characteristics of the human head, and in particular of the bony structure behind the ear. They are an essential tool in the calibration of bone-conduction hearing aids and audiometers. With the emergence of different types of artificial mastoids in the market, and the realisation that the visco-elastic part of these instruments changes over time, the development of a method of traceable calibration of these devices without relying on commercial software has become important for national metrology institutes. This paper describes commercially available calibration methods, and the development of a traceable calibration method including the traceable calibration of the impedance head used to measure the mechanical impedance of the artificial mastoid.

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.

Bonebridge Implantation for Conductive Hearing Loss in a Patient with Oval Window Atresia

The occurrence of oval window atresia is a rare anomaly with conductive hearing loss. Traditional atresia surgeries involve challenging surgical techniques with risks of irreversible inner ear damage. Recent reports on Bonebridge (Medel, Innsbruck, Austria), a novel implantable bone conduction hearing aid system, assert that the device is safe and effective for conductive hearing loss. We present a case of Bonebridge implantation in an eight-year-old girl with bilateral oval window atresia.

Bone-Conduction Hearing Aids

Bone-Conduction Hearing Aids

Bone-conduction hearing aids in an elderly population: complications and quality of life assessment.

To determine whether an elderly population with hearing impairment can be adequately rehabilitated with a bone-conduction hearing aid and whether the putative relationship between the elderly and an increased complication rate is justified. The study design was a retrospective case note review with a postal and telephone questionnaire, which was carried out in a tertiary centre. All patients aged 60 or over underwent implantation with a bone-conduction aid between 2009 and 2013 for conductive, SSD or mixed hearing loss. Outcome measures were complication rates and quality of life assessment using the Glasgow Benefit Inventory. The influence of patient and surgical factors on the complication rate was assessed. Fifty-one patients were implanted. Mean age was 67 years (range 60-89 years). The mean benefit, satisfaction and global GBI scores were 70 % (range 0-100 %), 70 % (0-100 %) and 82 % (83-100 %), respectively. The residual disability was 18 % (0-25 %). The adverse skin reaction rate was 16 % and the fixture loss rate was 2 %. There was a demonstrable increase in the complication rate with the dermatome (45 %; 5 patients) compared to the Sheffield 'S' (13 %; 2 patients) or linear incision techniques (29 %; 7 patients). The bone-conduction hearing aids are ideal method of hearing rehabilitation in the elderly for all forms of hearing loss. It provides significant benefit with no increased complication rate, which is imperative if social isolation is to be avoided and cognition preserved in this growing elderly population.

2E24 埋め込み型骨導補聴器の信号伝送効率の改善(OS5-6:臨床バイオメカニクスと医療デバイス(6))

2E24 埋め込み型骨導補聴器の信号伝送効率の改善(OS5-6:臨床バイオメカニクスと医療デバイス(6))

C202 埋め込み型骨導補聴器の経皮伝送法の最適化および音質評価(C2-1 医療・福祉機器)

C202 埋め込み型骨導補聴器の経皮伝送法の最適化および音質評価(C2-1 医療・福祉機器)

Osseointegration and its role in management of hearing loss

Osseointegration is a biological process by which a structural connection is created between living bone and the surface of a load-carrying implant. This phenomenon has been used in a range of medical interventions. In 1977, Tjellstrom reported on osseointegrated bone-anchored hearing device as an alternative to conventional bone-conducting hearing aids, which were required to be worn on a headband or a pair of glasses. Since that time, there has been significant development in surgical technique and device technology for bone-anchored hearing devices. A review of the current literature was conducted to describe these advancements and provide an up-to-date summary of the usage of osseointegrated bone-anchored hearing device in the management of hearing loss.

Is complex signal processing for bone conduction hearing aids useful?

ObjectivesTo establish whether complex signal processing is beneficial for users of bone anchored hearing aids.MethodsReview and analysis of two studies from our own group, each comparing a speech processor with basic digital signal processing (either Baha Divino or Baha Intenso) and a processor with complex digital signal processing (either Baha BP100 or Baha BP110 power). The main differences between basic and complex signal processing are the number of audiologist accessible frequency channels and the availability and complexity of the directional multi-microphone noise reduction and loudness compression systems.ResultsBoth studies show a small, statistically non-significant improvement of speech understanding in quiet with the complex digital signal processing. The average improvement for speech in noise is +0.9 dB, if speech and noise are emitted both from the front of the listener. If noise is emitted from the rear and speech from the front of the listener, the advantage of the devices with complex digital signal processing as opposed to those with basic signal processing increases, on average, to +3.2 dB (range +2.3 … +5.1 dB, p ≤ 0.0032).DiscussionComplex digital signal processing does indeed improve speech understanding, especially in noise coming from the rear. This finding has been supported by another study, which has been published recently by a different research group.ConclusionsWhen compared to basic digital signal processing, complex digital signal processing can increase speech understanding of users of bone anchored hearing aids. The benefit is most significant for speech understanding in noise.

Developmental Disorders of the Ear in Children and Adolescents

Developmental disorders of the ear can impair hearing and cause cosmetic deformities. In recent years, new surgical treatments have become established, above all in audiological rehabilitation. We selectively searched the PubMed database up to May 2013 for publications in English and Germanabout the therapeutic options. No randomized trials have been performed, for both ethical and practical reasons (inadmissibility of placebo surgery, specialization of surgeons for individual techniques). To correct prominent ears, cartilage-sparing suture techniques are preferred, as they lead less often than scoring and incisional techniques to the formation of persistent, incompletely correctable ridges and scaffolding defects. The successful esthetic rehabilitation of severe deformities of the external ear is achievable through pinna reconstruction with costal cartilage (main risks: tissue defect at donor site, scaffolding resorption) or porous polyethylene (main risk: implant extrusion). The functional rehabilitation of conductive or mixed hearing impairment due to ear-canal atresia and major middle-ear deformities is preferably achieved with active middle-ear implants or bone-conduction hearing aids. Functional rehabilitation should be provided even when the hearing impairment is unilateral, in order to improve directional hearing and hearing with ambient noise. In cases of purely cochlear, unilateral, severe hearing impairment or deafness, a boneconduction hearing aid can be tried, and the individual indication for a cochlear implant can be considered. The treatment options described here enable the affected children to benefit from complete functional and esthetic rehabilitation before they start school.

The role of stability measurements of the Baha® system in children

ObjectivePercutaneous bone conduction hearing aids are an established treatment for selected children unable to use conventional hearing aids. Currently in children, loading the implant is delayed for 3–6 months following fixture placement, due to concerns regarding bone quality, bone thickness and subsequent implant stability. Traditionally, such concerns led to children undergoing 2-stage Baha® surgery, with a second operation to attach the abutment after 3–6 months. Bone conduction implant stability can be objectively measured using resonance-frequency analysis (RFA) to generate Implant Stability Quotients (ISQs). We aimed to assess implant stability in children undergoing 1-stage surgery using RFA measurements and investigate the possible implications for earlier loading following surgery. MethodsWe report a case series of consecutive children undergoing Baha® at our tertiary paediatric hospital. The interval to implant loading remained 3–6 months for the duration of this study. RFA measurements were taken peri-operatively, 1 week post-surgery, within 3 months of surgery and then subsequently at follow up appointments. RFA measurements were also measured at loading of the hearing processor and at follow up appointments after loading. ResultsNine children received 10 Cochlear™ Baha® BI300 implants (8 unilateral and 1 bilateral) with a mean age of 9 years 4 months (4 years 9 months to 13 years 5 months). The mean time to loading of the hearing processor was 3.3 months (3 to 5 months, n=9) and mean follow up was 9 months (12 weeks to 23 months). Eight children had ISQs that were potentially sufficient to have loaded the implant earlier than 3 months. Implant stability was maintained after loading with the hearing processor. ConclusionThis study supports the potential use of RFA measurements to either, guide implant loading following 1-stage surgery in children, or to enable a larger prospective study of early loading (4–6 weeks) in children.

Sound transmission by cartilage conduction in ear with fibrotic aural atresia.

A hearing aid using cartilage conduction (CC) has been proposed as an alternative to bone conduction (BC) hearing aids. The transducer developed for this application is lightweight, requires a much smaller fixation force than a BC hearing aid, and is more convenient to use. CC can be of great benefit to patients with fibrotic aural atresia. Fibrotic tissue connected to the ossicles provides an additional pathway (termed fibrotic tissue pathway) for sound to reach the cochlea by means of CC. To address the function of fibrotic tissue pathway, BC and CC thresholds were measured in six ears with fibrotic aural atresia. The relationship between the CC thresholds and the results of computed tomography was investigated. In the ears with the presence of a fibrotic tissue pathway, the CC thresholds were lower than the BC thresholds at 0.5 and 1.0 kHz. At 2.0 kHz, no significant difference was observed between the BC and CC thresholds. The current findings suggest that sound in the low to middle frequency range is transmitted more efficiently by CC via a fibrotic tissue pathway than BC. The development of hearing devices using CC can contribute to rehabilitation, particularly in patients with fibrotic aural atresia.

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.

J0210105 埋め込み型骨導補聴器用振動子の振動特性改善([J021-01]診療技術と臨床バイオメカニクスセッション(1))

J0210105 埋め込み型骨導補聴器用振動子の振動特性改善([J021-01]診療技術と臨床バイオメカニクスセッション(1))

Mitigation of Informational Masking in Individuals With Single-Sided Deafness by Integrated Bone Conduction Hearing Aids

To confirm an increased susceptibility to informational masking among individuals with single-sided deafness (SSD). To demonstrate a reduction in informational masking when SSD is treated with an integrated bone conduction hearing aid (IBC). To identify the acoustic cues that contribute to IBC-aided masking release. To determine the effects of device experience on the IBC advantage. Informational masking was evaluated with the coordinate-response measure. Participants performed the task by reporting color and number coordinates that changed randomly within target sentences. The target sentences were presented in free field accompanied by zero to three distracting sentences. Target and distracting sentences were spoken by different talkers and originated from different source locations, creating two sources of information for auditory streaming. Susceptibility to informational masking was inferred from the error rates of unaided SSD patients relative to normal controls. These baseline measures were derived by testing inexperienced IBC users without the device on the day of their initial fitting. The benefits of IBC-aided listening were assessed by measuring the aided performance of users who had at least 3 months' device experience. The acoustic basis of the listening advantage was isolated by correlating response errors with the voice pitch and location of distracting sentences. The effects of learning on cue effectiveness were evaluated by comparing the error rates of experienced and inexperienced users. Unaided SSD participants (inexperienced users) performed as well as normal controls when tested without distracting sentences but produced significantly higher error rates when tested with distracting sentences. Most errors involved responding with coordinates that were contained in distracting sentences. This increased susceptibility to informational masking was significantly reduced when experienced IBC users were tested with the device. The listening advantage was most strongly correlated with the availability of voice pitch cues, although performance was also influenced by the location of distracting sentences. Directional asymmetries appear to be dictated by location-dependent cues that are derived from the distinctive transmission characteristics of IBC stimulation. Experienced users made better use of these cues than inexperienced users. These results suggest that informational masking is a significant source of communication impairment among individuals with SSD. Despite the lateralization of auditory function, unaided SSD subjects experience informational masking when distractors occur in either the deaf or normal spatial hemifield. Restoration of aural sensitivity in the deaf hemifield with an IBC enhances speech intelligibility under complex listening conditions, presumably by providing additional sound-segregation cues that are derived from voice pitch and spatial location. The optimal use of these cues is not immediate, but a significant listening advantage is observed after 3 months of unstructured use.

C202 骨導補聴器用トランスデューサーにより発生する振動の三次元計測(C2-1 医療・福祉関連機器2,臨床バイオメカニクス)

C202 骨導補聴器用トランスデューサーにより発生する振動の三次元計測(C2-1 医療・福祉関連機器2,臨床バイオメカニクス)