Binaural Hearing Using the ADHEAR Bone Conduction System in the Monaurally Occluded Ear.

INTRODUCTION: The study aimed to investigate binaural cues in the rehabilitation of unilateral occluded ears with a bone conduction hearing aid. METHODS: The study sample consisted of 40 adult volunteers with normal hearing. Unilateral pseudo-conductive hearing loss was induced by inserting an earplug into the external auditory canal (EAC) and silicone material in the concha for ear impression. The adaptive speech-in-noise test (Italian Matrix test) was performed in three spatial orientations to assess binaural cues (summation, squelch, and head shadow effects). All evaluations were performed in the normal condition, after EAC occlusion, and after application of an adhesive bone conduction hearing aid. Binaural contrast differences were calculated in the three conditions. RESULTS: In the EAC occlusion condition, there was a significant increase in the signal-to-noise ratio (SNR) in both the S0N0 (2.4 dB) and the S90N-90 (7.7 dB) settings, and a slight albeit significant increase in the S0N90 setting (1.35 dB). After fitting the BC hearing aid, there was a reduction of -1.8 dB SNR (p < 0.001) in the S0N0 setting and -2 dB (p = 0.003) in the S90N-90 setting. There was no improvement in the SNR (p = 0.405) in evaluation of the squelch effect (S0N90). These data were corroborated by a better binaural contrast due to a reduction in the summation effect in the monaural occlusion condition and a subsequent reduction in binaural contrast after fitting the hearing aid due to an increase in the summation effect (-2.5 dB vs. 0.3 dB; p < 0.001). CONCLUSIONS: Application of a bone conduction hearing aid in unilateral pseudo-conductive hearing loss strengthens speech recognition of noise by improving the summation effect and impeding the shadow effect of the head; however, there appears to be no improvement in speech perception in noise due to spatial release from masking.

Surgical results of transcutaneous bone-anchored hearing aid comparing the C-shaped and linear incision techniques.

PURPOSE: The aim of the study is to compare the operative time and postoperative complication outcomes for bone-anchored hearing aid (BAHA) implants using two different techniques: the C-shaped incision technique and the linear incision technique. METHODS: An analysis was carried out of 38 patients implanted with transcutaneous BAHAs during a 4-year period in a single otolaryngology department. RESULTS: The implantation was carried out under general anesthesia. Operative time was significant lower with the linear technique compared to the C-shaped technique (76.55 min, SD 16.75 vs. 93.17 min, SD 19.82; p = 0.007). There was no difference in postoperative complications between the two techniques. CONCLUSIONS: The use of linear incision for transcutaneous BAHA system implantation is associated with a reduced surgery time compared to the C-shaped technique, with no increase in postoperative complications.

[Atresia or severe stenosis of the external auditory canals with normal auricles in children]. / Atreziya ili vyrazhennyi stenoz naruzhnykh slukhovykh prokhodov pri normal'nykh ushnykh rakovinakh u detei.

In the article we present the experience of observing 27 children with bilateral stenosis or atresia of the external auditory canals with normal or slightly hypoplastic auricles. Three children had bilateral stenosis of the external auditory canals due to abnormal or premature fusion of the skull bones. The remaining 24 children had external auditory canals atresia in the bone part or throughout. 9 of them had a syndrome of deletion of the long arm of chromosome 18, 1 child had a mosaic form of Edwards syndrome. The average age at the time of diagnosis was 4 years 3 months. Atresia of external auditory canals in normal auricle is often caused by abnormalities of 18 pairs of chromosomes, and severe stenosis of external auditory canals can be observed in children with craniostenosis and other anomalies of the skull bones.

Audiological effectiveness of Bonebridge implantation for bilateral congenital malformation of the external and middle ear.

PURPOSE: To evaluate the audiological effectiveness of Bonebridge implantation in patients with bilateral congenital malformation of the external and middle ear. METHODS: Twenty-eight cases [17 boys and 11 girls; median age, 12 years (range 8-36 years)] had unilateral Bonebridge implantation. Audiological tests were performed preoperatively and postoperatively, and included the pure-tone audiometry test, speech discrimination score (SDS), and evaluation of the unaided and aided hearing thresholds in sound fields. For the group of patients aged > 12 years, Mandarin Speech Test Materials were used to determine the SDS. For the other cases, the Mandarin Lexical Neighborhood Test was used. The daily life efficacy was assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire postoperatively. The t and t' tests were used in the statistical analyses. RESULTS: The hearing threshold with the Bonebridge improved by 25-35 dB HL, compared to that of the unaided condition. The SDS of patients aged > 12 years improved by about 50%; the SDS also improved by 10-20% in the three patients aged < 12 years. According to the APHAB, the mean Bonebridge scores of ease of communication, background noise, and reverberation decreased by 60.3 ± 15.7, 50.2 ± 11.1, and 59.4 ± 7.8, respectively, compared to the preoperative scores, and the Bonebridge score of aversiveness was higher (69.8 ± 10.8) than the unaided score. CONCLUSIONS: The audiological effectiveness of the Bonebridge was significant and noticeable in bilateral congenital malformation of the external and middle ear. The Bonebridge can be an alternative and effective solution for those patients to improve hearing.

Active Bone Conduction Implant and Adhesive Bone Conduction Device: A Comparison of Audiological Performance and Subjective Satisfaction.

Introduction Atresia of the external auditory canal affects 1 in every 10 thousand to 20 thousand live births, with a much higher prevalence in Latin America, at 5 to 21 out of every 10 thousand newborns. The treatment involves esthetic and functional aspects. Regarding the functional treatment, there are surgical and nonsurgical alternatives like spectacle frames and rigid and softband systems. Active transcutaneous bone conduction implants (BCIs) achieve good sound transmission and directly stimulate the bone. Objective To assess the audiological performance and subjective satisfaction of children implanted with an active transcutaneous BCI for more than one year and to compare the outcomes with a nonsurgical adhesive bone conduction device (aBCD) in the same users. Methods The present is a prospective, multicentric study. The audiological performance was evaluated at 1, 6, and 12 months postactivation, and after a 1-month trial with the nonsurgical device. Results Ten patients completed all tests. The 4-frequency pure-tone average (4PTA) in the unaided condition was of 65 dB HL, which improved significantly to 20 dB HL after using the BCI for 12 months. The speech recognition in quiet in the unaided condition was of 33% on average, which improved significantly, to 99% with the BCI, and to 91% with the aBCD. Conclusion The aBCD demonstrated sufficient hearing improvement and subjective satisfaction; thus, it is a good solution for hearing rehabilitation if surgery is not desired or not possible. If surgery is an option, the BCI is the superior device in terms of hearing outcomes, particularly background noise and subjective satisfaction.

Ten years' experience with bone conduction hearing aids in the Western Cape, South Africa.

Untreated conductive and mixed hearing losses as a result of middle ear pathology or congenital ear malformations can lead to poor speech, language and academic outcomes in children. Lack of access to centralised hearing healthcare in resource-constrained environments limits opportunities for children with hearing loss. Red Cross War Memorial Children's Hospital (RCWMCH) is one of only two dedicated paediatric hospitals in sub-Saharan Africa. Between 2016 and 2021, 29 children received implanted bone conduction hearing devices, and 104 children were fitted with bone conduction devices on softbands. The authors' experience at RCWMCH suggests that bone-anchored hearing devices, either fitted on softbands or on implanted abutments, can provide solutions in settings where patients have limited access to hearing healthcare and optimal classroom environments. Hearing healthcare should be accessible and delivered at the appropriate level of care to mitigate the adverse effects of hearing loss in children.Contribution: This article describes strategies employed at RCWMCH such as fitting bone conduction hearing devices on a softband immediately after hearing loss diagnosis and conducting follow-up via remote technology to make hearing healthcare more accessible to vulnerable populations.

[Intervention effects of bone conduction hearing aids in patients with single-sided deafness and asymmetric hearing loss].

The incidence of single-sided deafness（SSD） is increasing year by year. Due to the hearing defects of one ear, the ability of sound localization, speech recognition in noise, and quality of life of patients with single-sided deafness will be affected to varying degrees. This article reviews the intervention effects of different types of bone conduction hearing aids in patients with single-sided deafness and asymmetric hearing loss, and the differences of intervention effects between bone conduction hearing aids, contralateral routing of signal（CROS） aids, and cochlea implant（CI）, to provide a reference for the auditory intervention and clinical treatment of single-sided deafness and asymmetric hearing loss.

Comparative Analysis of Cartilage Conduction Hearing Aid Users and Non-Users: An Investigative Study.

Clinical findings on cartilage conduction hearing aids (CCHAs) have gradually become clear; however, few reports include a large number of cases. This study included 91 ears from 69 patients who underwent CCHA fitting in our hospital. Their ears were divided into six groups (i.e., bilateral aural atresia or severe canal stenosis, unilateral aural atresia or severe canal stenosis, chronic otitis media or chronic otitis externa with otorrhea, sensorineural hearing loss, mixed hearing loss, and conductive hearing loss) according to their clinical diagnosis and type of hearing loss. Most clinical diagnoses were aural atresia or meatal stenosis (bilateral, 21.8%; unilateral, 39.6%). The purchase rate of CCHAs was higher in the closed-ear group (bilateral, 77.3%; unilateral, 62.5%). In the bilateral closed-ear group, air conduction thresholds at 1000, 2000, and 4000 Hz and aided thresholds with CCHAs at 4000 Hz were significantly lower in the purchase group than the non-purchase group. No significant difference was observed between the purchase and non-purchase groups in the unilateral closed-ear group. In the bilateral closed-ear group, air conduction thresholds and aided thresholds were associated with the purchase rate of CCHAs. In the unilateral closed-ear group, factors other than hearing might have affected the purchase rate of CCHAs.

Benefits of bone conduction hearing aid in children with unilateral aural atresia.

Objective: To assess the hearing benefit with a unilateral bone conduction hearing aid in a cohort of children with unilateral aural atresia. Methods: Cross-sectional case series pilot study involving 7 children (median age: 10 years, range 6-11). All patients underwent pure-tone, speech, aided sound field and aided speech audiometry and Simplified Italian Matrix Test (SIMT) with and without bone conduction hearing aid (Baha 5® CochlearTM). Cognitive abilities were assessed in 5 patients. Results: The mean air conduction pure-tone average (PTA) of the atretic ear was 63.2 ± 6.9 dB, while the bone conduction PTA was 12.6 ± 4.7 dB. Speech discrimination score of the atretic ear was 88.6 ± 3.8 dB, while with the hearing aid it was 52.8 ± 1.9 dB. In the contralateral ear, there was no significant air-bone gap, and PTAs for air and bone conduction thresholds were within normal range (PTA ≤ 25 dB). The mean aided air conduction hearing threshold was 26.2 ± 7.97. Mean speech recognition threshold without the hearing aid was -5.1 ± 1.9 dB, and -6.0 ± 1.7 dB with the hearing aid tested with the SIMT. The mean score of the cognitive test was 46.8 ± 42.8. Conclusions: These preliminary findings should encourage clinicians in proposing a unilateral bone conduction hearing aid in children with unilateral atresia.

An objective bone conduction verification tool using a piezoelectric thin-film force transducer.

All hearing aid fittings should be validated with appropriate outcome measurements, whereas there is a lack of well-designed objective verification methods for bone conduction (BC) hearing aids, compared to the real-ear measurement for air conduction hearing aids. This study aims to develop a new objective verification method for BC hearing aids by placing a piezoelectric thin-film force transducer between the BC transducer and the stimulation position. The newly proposed method was compared with the ear canal method and the artificial mastoid method through audibility estimation. The audibility estimation adopted the responses from the transducers that correspond to the individual BC hearing thresholds and three different input levels of pink noise. Twenty hearing-impaired (HI) subjects without prior experience with hearing aids were recruited for this study. The measurement and analysis results showed that the force transducer and ear canal methods almost yielded consistent results, while the artificial mastoid method exhibited significant differences from these two methods. The proposed force transducer method showed a lower noise level and was less affected by the sound field signal when compared with other methods. This indicates that it is promising to utilize a piezoelectric thin-film force transducer as an in-situ objective measurement method of BC stimulation.

Transcranial attenuation in bone conduction stimulation.

In bone conduction (BC) stimulation, the sound travels from the site of stimulation to the ipsilateral and contralateral cochlea. A frequency dependent reduction in BC hearing sensitivity occurs when sound travels to the contralateral cochlea as compared to the ipsilateral cochlea. This effect is called transcranial attenuation (TA) that is affected by several factors. Experimental and clinical studies describe TA and the factors that have an effect on it. These factors include stimulus location, coupling of a bone conduction hearing aid to the underlying tissue, and the properties of the head (such as geometry of the head, thickness of the skin and/or skull, changes due to aging, iatrogenic changes such as bone removal in mastoidectomy, and occlusion of the external auditory canal). While TA has an effect of the patient's benefit of BCHAs, there seems to be a discrepancy between experimental measurements and clinical relevance. The effects are small and the interindividual variability, in comparison, is rather large. However, a better understanding of these factors may help to determine the site of attachment, the coupling mode, and possibly the fitting of a BCHA, depending on its indication.

Bone-conduction hearing aid is effective in congenital oval window atresia.

BACKGROUND: Implantable bone-conduction hearing aids (BCHA) are effective in patients with congenital ear malformations.However, there is no large sample study to verify the efficacy of Bonebridge in patients with congenital oval window atresia. OBJECTIVES: To investigate efficiency of implantable bone-conduction hearing aids in Mandarin-speaking patients with congenital oval window atresia. MATERIAL AND METHODS: We retrospectively analyzed 15 patients, who were confirmed with either unilateral or bilateral congenital oval window atresia by temporal bone CT. All patients were implanted with a bone-conduction hearing device between July 2016 and July 2019 at Beijing Tongren Hospital, Capital Medical University. Pure tone audiometry (PTA), air-bone gap (ABG), speech discrimination scores (SDSs), and hearing thresholds were performed. RESULTS: Postoperative complications including facial paralysis were particularly rare. Unaided mean sound field threshold was 62.2 ± 10.5 dBHL and that with implantable bone-conduction hearing aids was 39.1 ± 13.2 dBHL (p < 0.01). The mean speech discrimination scores improved greatly (p < 0.01), specifically with regard to sentence and disyllabic words. CONCLUSIONS: Patients with congenital oval window atresia often show moderate to severe conductive hearing loss. Implantable bone-conduction hearing aids are considerably safe and stable for hearing rehabilitation. It is a novel treatment modality for Mandarin-speaking patients with congenital oval window atresia.

Numerical analysis of the effects of ossicular chain malformations on bone conduction stimulation.

To assess the effects of ossicular chain malformations on the performance of bone conduction hearing aids, a human ear finite-element model that includes an ear canal, a middle ear, and a spiral cochlea incorporating the third windows was established. This finite element model was built based on micro-computed tomography scanning and reverse modelling techniques, and the reliability of the finite element model was verified by comparison with reported experimental data. Based on this model, two main types of ossicular chain malformations, i.e., the incudostapedial disconnection and the ossicles fixation, were simulated, and their influences on bone conduction were analyzed by comparing the trans-cochlear-partition differential pressures. The results indicate that the incudostapedial disconnection mainly deteriorates the bone conduction response at mid frequencies. The stapes fixation has the largest effect among the ossicles fixation with the bone conduction stimulation, which also mainly decreases the mid-frequency response of the bone conduction, especially at 2 kHz. As the speech intelligibility has the most important frequency range at the range between 1 kHz and 2.5 kHz, the mid-frequency deterioration caused by ossicular chain malformations should be compensated in optimizing the design of the bone conduction hearing aids. For treating patients with the ossicular chain malformations, especially for the patients who suffer from the stapes fixation, the output of bone conduction hearing aids' actuator in the middle frequency band should be improved.

Audiological and subjective outcomes of 100 implanted transcutaneous bone conduction devices and preoperative bone conduction hearing aids in patients with bilateral microtia-atresia.

Background: Bonebridge (BB) and bone conduction hearing aid (BCHA) are effective in patients with bilateral congenital microtia-atresia (CMA).Objectives: To investigate and compare the outcomes of these devices in a large sample size.Materials and methods: This single center prospective study involved 100 patients with bilateral CMA who were implanted with BBs and used BCHAs before implantation. Sound field threshold (SFT), speech reception thresholds (SRTs) and word recognition scores (WRSs) were compared between unaided, BCHA used and implanted patients. The Abbreviated Profile of Hearing Aid Benefit (APHAB) was used to evaluate subjective satisfaction.Results: Compared to unaided condition, the SFT, WRS and SRT of BCHA and BB were significantly improved. With BCHA or BB, the three subscale scores of the APHAB (ease of communication, background noise and reverberation) significantly reduced. However, the aversiveness subscale scored significantly higher than unaided condition. All outcomes were better in BB condition than BCHA.Conclusions: BB or BCHA use can be considered as effective methods to improve audiological outcomes and subjective satisfaction. Although not as good as BB, BCHA use is critical for improving hearing in the early period of language and auditory pathway development before the skull is suitable for BB implantation.

Active Bone Conduction Implant and Adhesive Bone Conduction Device: A Comparison of Audiological Performance and Subjective Satisfaction

Abstract Introduction Atresia of the external auditory canal affects 1 in every 10 thousand to 20 thousand live births, with a much higher prevalence in Latin America, at 5 to 21 out of every 10 thousand newborns. The treatment involves esthetic and functional aspects. Regarding the functional treatment, there are surgical and nonsurgical alternatives like spectacle frames and rigid and softband systems. Active transcutaneous bone conduction implants (BCIs) achieve good sound transmission and directly stimulate the bone. Objective To assess the audiological performance and subjective satisfaction of children implanted with an active transcutaneous BCI for more than one year and to compare the outcomes with a nonsurgical adhesive bone conduction device (aBCD) in the same users. Methods The present is a prospective, multicentric study. The audiological performance was evaluated at 1, 6, and 12 months postactivation, and after a 1-month trial with the nonsurgical device. Results Ten patients completed all tests. The 4-frequency pure-tone average (4PTA) in the unaided condition was of 65 dB HL, which improved significantly to 20 dB HL after using the BCI for 12 months. The speech recognition in quiet in the unaided condition was of 33% on average, which improved significantly, to 99% with the BCI, and to 91% with the aBCD. Conclusion The aBCD demonstrated sufficient hearing improvement and subjective satisfaction; thus, it is a good solution for hearing rehabilitation if surgery is not desired or not possible. If surgery is an option, the BCI is the superior device in terms of hearing outcomes, particularly background noise and subjective satisfaction.

Comparative outcomes of active and passive hearing devices by transcutaneous bone conduction.

Conclusion Bonebridge (BB) and Sophono (SP) devices improved hearing; with the BB implant showing a better performance at medium and high frequencies. Furthermore, the BB, as an active implant, showed higher functional gain and increased time of use, when compared to the SP, a passive system. Objectives This study aims to compare surgical and audiological outcomes of SP and BB devices in order to assess and further differentiate the indication criteria. Methods Fourteen patients with conductive and mixed hearing loss were evaluated pre- and post-operatively (BB or SP) (period 2013-2014). Age, gender, surgical history, cause and type of hearing loss, implant use per day, levels of bone and air conduction, and functional gain were recorded. Data was analysed by Wilcoxon singed-rank and Wilcoxon rank-sum tests. Results Fourteen patients (BB; n = 10 and SP; n = 4) with an average age = 25.42 years (CI95 = 12.41-38.43) were evaluated. The gender relation was equal (1:1), with pre-implantation osseous thresholds of 20.42 dB (CI95 = 11.15-29.69), and pre-implantation aerial thresholds of 70.83 dB (CI95 = 62.52-79.14). The SP wearing time was significantly lower than that of the BB (SP = 7-10 h/day, BB = 8-12 h/day; p = 0.0323). The functional gain did not differ significantly between the two devices (BB = 40.00 ± 13.19 dB, SP = 34.06 ± 15.63 dB; p = 0.3434), but a significant improvement from pre- to post-implantation was observed (p < 0.05). BB and SP decreased auditory thresholds at 1 and 2 kHz (< 0.01), respectively. The BB even significantly decreased thresholds at 0.5 kHz (p = 0.0140) and 4 kHz (p < 0.0001). No relevant surgical complications were found.