Effects of applied contact force and volume control setting on output force levels of the BAHA Softband

[Nonsurgical attachment possibilities for bone conduction hearing aids : Comparison of coupling using external pressure versus an adhesive plate]

BACKGROUND

Bone conduction hearing systems are used for patients with conductive or combined hearing loss who cannot be adequately treated with air conduction hearing aids or surgery. These hearing systems can be surgically implanted or reversibly attached using bone conduction eyeglasses or a rigid or soft headband. A nonsurgical and pressure-free alternative is fixation via an adhesive plate.

OBJECTIVE

The aim of this study was to compare the energy transferred from the hearing aid to the mastoid when attached via a new adhesive plate versus via a soft headband. In addition, the comfort and the durability of the adhesive plate was evaluated.

MATERIALS AND METHODS

A total of 30 subjects were tested. The transferred energy was measured by accelerometer, which recorded the sound energy at the maxillary teeth. Wearing comfort, fixation duration (until plate becomes loose), and the skin reaction were examined using a questionnaire after the subjects had worn the adhesive plate with and without hearing aid for a maximum of 7 days. The skin reaction was also assessed clinically.

RESULTS

There was a significant difference in the transferred energy in favor of the soft headband at 0.5, 1, and 2 kHz. On the other hand, there was a high level of satisfaction and acceptance regarding the aesthetics and the wearing time of the adhesive plate, without skin irritations.

CONCLUSION

The difference in the transferred energy up to 2 kHz is probably due to the lack of pressure from the adhesive plate. This could possibly be compensated after appropriate adjustment of the speech processor. Based on the positive properties of the adhesive plate in terms of comfort, it could be used as an alternative to the soft headband.

Audiological and subjective benefit with a new adhesive bone conduction hearing aid in children with congenital unilateral microtia and atresia

PURPOSE

This study aimed to evaluate the audiological benefits and subjective satisfaction in using a new adhesive bone conduction hearing aid in children with congenital unilateral microtia and atresia.

METHODS

We evaluated the effectiveness of the hearing aid using the sound field hearing threshold, speech recognition ability under quiet and noise, and subjective questionnaires in 13 children (5-15 years old).

RESULTS

The mean sound field hearing threshold significantly improved with a gain of 25.4 ± 4.9 dB HL. Mean word recognition scores were ameliorated in quiet and noise by 1.9 ± 2.5% and 7.3 ± 5.3%, respectively. Speech recognition ability results in noise varied; when the speech signal and noise were presented from the front, the mean speech recognition ability improved by 2.5 ± 1.6 dB signal-to-noise ratios (SNR). When noise was presented towards the normal hearing side, speech understanding was improved by 2.9 ± 1.6 dB SNR. When the speech signal was presented from the atretic side with noise from the normal hearing side, an improvement of 5.7 ± 3.4 dB SNR (p < 0.001) was noted. However, when noise was presented towards the newly aided atretic ear, no statistical significance was found. The questionnaire results indicated that the hearing device provided benefits in speech recognition ability in different complex situations, with high satisfaction rates.

CONCLUSION

The adhesive bone conduction hearing aid investigated here offers a concealed and aesthetic method to improve hearing in children with congenital unilateral microtia and atresia during their early years, with high subjective satisfaction.

Clinical consensus document for fitting non-surgical transcutaneous bone conduction hearing devices to children

This clinical consensus document addresses the assessment, selection, and fitting considerations for non-surgical bone conduction hearing devices (BCHD) for children under the age of 5 years identified as having unilateral or bilateral, permanent conductive or mixed hearing losses. Children with profound unilateral sensorineural hearing losses are not addressed. The document was developed based on evidence review and consensus by The Paediatric Bone Conduction Working Group, which is composed of audiologists from North America who have experience working with BCHDs in children. The document aims to provide clinical direction for an area of paediatric audiology practice that is under development and is therefore lacking in standard protocols or guidelines. This work may serve as a basis for future research and clinical contributions to support prospective paediatric audiology practices.

Long-term evaluation of development in patients with bilateral microtia using softband bone conducted hearing devices

OBJECTIVE

The ability of early intervention with softband bone conducted hearing device (BCHD) to ensure normal development of speech, language and psychosocial situations remains undetermined. We aimed to evaluate auditory and speech development, as well as psychosocial situations of children with bilateral microtia fitted with a softband BCHD for 3-5 years.

METHODS

The study included 53 patients with bilateral microtia and 53 sex- and age-matched children with normal hearing. Auditory development was evaluated using the Meaningful Auditory Integration Scale (MAIS) and Categories of Auditory Performance (CAP). Speech Intelligibility Rating (SIR) and Meaningful Use of Speech Scale (MUSS) were used to assess speech development. The psychometric properties of these patients were evaluated using Achenbach's Child Behavior Checklist (CBCL), and subjective benefits were measured using the Glasgow Children's Benefit Inventory (GCBI) questionnaire.

RESULTS

The average unaided and aided hearing thresholds measured using VRA were 73.8 ± 5.1 dB HL and 30.5 ± 6.0 dB HL, respectively. The total MAIS scores of the patients were 89.6 ± 9.6% and 93.0 ± 8.8% of normal hearing children at the last follow-up. The CAP scores of the two groups were 6.5 ± 1.3 and 6.9 ± 0.3, respectively. The mean MUSS score of the patients and the control group were 31.9 ± 7.0 and 34.3 ± 6.0, respectively. The mean SIR score of the two groups were 4.6 ± 0.7 and 4.8 ± 0.4. CBCL found that only two patients could be considered problematic psychosocially. The average benefit score on the GCBI was 32.9 ± 29.3.

CONCLUSIONS

Softband BCHD significantly improved auditory development in patients with bilateral microtia, with speech development reaching the level of normal hearing peers. No significant behavioral problems were found in the patients, with subjective evaluations showing that softband BCHD improved patient quality of life.

First Results With a New, Pressure-free, Adhesive Bone Conduction Hearing Aid

OBJECTIVES

The aim of this study was to evaluate the hearing benefit, advantages, and disadvantages in a series of patients using a new, nonimplantable, pressure-free, adhesive bone conduction hearing aid.

METHODS

Twelve patients were included in the study at the ear, nose, and throat department of the Medical University of Vienna. All patients suffered from conductive hearing loss for at least 3 months. A sound field audiometry, Freiburg monosyllables word test and Oldenburg sentence test were carried out. Additionally, sound quality (SSQ12) and quality of life (AQoL-8D) were assessed using questionnaires.

RESULTS

Analysis revealed an average aided threshold of 30.8 dB HL (±7.1 SD) and an unaided threshold of 45.1 dB HL (±7.0 SD), resulting in a statistically significant (p < 0.001) average functional gain. Additionally, participants experienced about 30% gain in word recognition scores at 65 dB sound pressure level, speech reception threshold in quiet was 56.8 dB (±6.1) and improved to 44.5 dB (±6.4) in the aided condition. Both, the SSQ12 and the AQoL-8D showed a statistically significant improvement when comparing the scores at the beginning of the study to the answers after 2 weeks of device usage (SSQ12 (p < 0.002) and AQoL-8D (p = 0.002)). Neither skin irritations nor pain were reported during the study period.

CONCLUSION

In conclusion, this new, adhesive bone conduction hearing aid has a high patient satisfaction rate while causing no skin irritation or pain.

Measurement of Skull Size on Computed Tomography Images for Developing a Bone Conduction Headset Suitable for the Korean Standard Head Size

Background and Objectives

We aimed to measure the head dimensions on computed tomography (CT) images, to compare them to directly measured head dimensions, and to predict a new parameter of bone thickness for aiding bone conduction implant (BCI) placement.

Subjects and Methods

We reviewed the facial and mandibular bone CT images of 406 patients. Their head sizes were analyzed using five parameters included in the 6th Size Korea project, and they were divided into age groups (ranging from the 10s to the 80s). We compared the head length, head width, sagittal arc, bitragion arc, and head circumference in the CT and Size Korea groups. We also added the parameter bone thickness for aiding BCI placement.

Results

All the head size parameters measured using CT were significantly smaller than those measured directly, with head length showing the smallest difference at 7.85 mm. The differences in the other four parameters between the two groups according to patient age were not statistically significantly different. Bone thickness had the highest value of 4.89±0.93 mm in the 70s and the lowest value of 4.10±0.99 mm in the 10s. Bone thickness also significantly correlated with head width (p=0.038).

Conclusions

Our findings suggested that the CT and direct measurements yielded consistent data. Moreover, CT enabled the measurement of bone sizes, including bone thickness, that are impossible to measure directly. CT measurements may complement direct measurements in the Size Korea data when used for developing bone conduction hearing devices (BCIs and headsets) for the Korean population.

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

INTRODUCTION

To compare the audiological results of Bone Conduction Hearing Aid (BCHA) on hard test band and Bonebridge (BB) implant among children with microtia and atresia.

METHODS

This 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.

RESULTS

Ten 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.

CONCLUSION

In audiologic assessments BB performs comparably to BCHA among children with microtia and atresia.

A Review of Temporal Bone CT Imaging With Respect to Pediatric Bone-anchored Hearing Aid Placement

OBJECTIVE

Bone-anchored hearing aid has been shown to be effective in hearing rehabilitation for conductive loss or single-sided deafness. Current FDA guidelines allow implantation in patients over 5 years old. This guideline is at least partially due to concern for thickness of bone stock at the implant site. We aim to investigate whether temporal bone thickness should be a deterrent to implantation in those younger than five.

STUDY DESIGN

A retrospective review of high-resolution temporal bone computed tomographies (CTs) comparing measurements between ears with chronic disease and controls.

SETTING

Single institution tertiary care center.

PATIENTS

One hundred patients between 1 and 5.99 years had temporal bone CTs performed between 2000 and 2009. Patients with chronic ear disease were identified by ICD-9 code, as well as confirmation by review of the imaging.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURES

Temporal bone thickness was measured on axial CT slices at a point 1 cm posterior to the sigmoid sinus, at the superior margin of the bony canal.

RESULTS

Average thickness was greater than 3 mm in all age groups. No significant difference was found between age groups, or between normal ears and ears with chronic disease (3.5 mm versus 3.3 mm, p = 0.21) when compared individually.

CONCLUSION

This data shows pediatric temporal bone thickness is frequently greater than the recommended 3 mm, even in patients as young as one. Anatomically, concerns regarding temporal bone thickness in patients younger than five could be reliably addressed with imaging typically obtained in workup of hearing loss.

Comparison of hearing thresholds obtained with Baha preoperative assessment tools and those obtained with the osseointegrated implant

We conducted a study of the Baha bone-anchored hearing aid system to quantify the difference between (1) hearing thresholds obtained through preoperative testing methods with the Baha sound processor attached to three different bone-conduction testing devices and (2) thresholds obtained postoperatively with the sound processor attached to a surgically placed osseointegrated titanium implant. Twenty-three patients underwent free-field testing in four situations: with the Baha sound processor attached to (1) the Baha Testband (transcutaneous transmission), (2) the Baha Softband (transcutaneous transmission), (3) a test rod (bone conduction via the teeth), and (4) the osseointegrated implant (percutaneous transmission). The main outcome measure was the result of a comparison of the thresholds obtained with the three preoperative test methods and those obtained with the osseointegrated implant. We found that aided thresholds obtained with the osseointegrated implant were significantly better (p < 0.05) than those obtained with the three preoperative test methods. The degree of superiority increased with higher frequencies. We conclude that thresholds of 1 to 18 dB better than those obtained by preoperative test methods can be expected postoperatively with the osseointegrated implant. The damping effect of sound transmission via the teeth or transcutaneously must be accounted for in making predictions of postoperative outcome.

Speech recognition with BAHA simulator in subjects with acquired unilateral sensorineural hearing loss

CONCLUSION

We question the justification for the cost of a surgically implanted device for the restoration of limited circumstances of audible communication, although we understand that the decision is taken depending on the social relevance of communication or personal criteria.

OBJECTIVES

The purpose of this study was to evaluate the effect of the BAHA simulator (BAHAS) system in subjects with acquired unilateral sensorineural hearing loss. In particular we tested the changes of speech reception threshold (SRT) in relation to different speech source positions, with a background of diffuse noise.

METHODS

The primary message consisting of lists of Italian sentences was delivered from a loudspeaker placed at horizontal azimuths of 0°, 90°, 180° and 270°; the interference consisted of uncorrelated speech-shaped noise simultaneously delivered by four loudspeakers at a fixed intensity. The speech recognition tests were administered to 11 patients with BAHAS either on or off; hence each patient underwent 8 acoustic conditions (4 primary message directions × 2 BAHAS conditions). The SRT (50% correct responses) was measured by a simple 2 dB step adaptive procedure. Ten normal-hearing subjects served as the control group.

RESULTS

Our data demonstrated that even for the acoustic condition where BAHAS should be more useful (i.e. lateral speech toward the impaired side), it was definitely ineffective in the study conditions.

Effect of static force on bone conduction hearing thresholds and comfort

OBJECTIVE

To assess the effect of the static force of a bone vibrator on the results of bone conduction (BC) threshold measurements and comfort.

DESIGN

BC thresholds were determined for 40 participants using the standardized P-3333 headband and a leather adjustable headstrap with variable static forces (2.4, 3.4, 4.4, 5.4 N). Comfort ratings were examined using a five-point Likert scale.

RESULTS

Mean BC thresholds were within ± 2 dB across all conditions; differences may be considered small enough to be clinically insignificant. Participants experienced significantly greater discomfort with the P-3333 versus the adjustable headstrap. The mean static force of the P-3333 varied considerably and was higher in situ than the calibration standard of 5.4 N.

CONCLUSIONS

The results suggest that future revisions of relevant international and national standards should address the use of an adjustable headstrap and a static force less than 5.4 N.

Preliminary evaluation of a novel bone-conduction device for single-sided deafness

HYPOTHESIS

A new intraoral bone-conduction device has advantages over existing bone-conduction devices for reducing the auditory deficits associated with single-sided deafness (SSD).

BACKGROUND

Existing bone-conduction devices effectively mitigate auditory deficits from single-sided deafness but have suboptimal microphone locations, limited frequency range, and/or require invasive surgery. A new device has been designed to improve microphone placement (in the ear canal of the deaf ear), provide a wider frequency range, and eliminate surgery by delivering bone-conduction signals to the teeth via a removable oral appliance.

METHODS

Forces applied by the oral appliance were compared with forces typically experienced by the teeth from normal functions such as mastication or from other appliances. Tooth surface changes were measured on extracted teeth, and transducer temperature was measured under typical use conditions. Dynamic operating range, including gain, bandwidth, and maximum output limits, were determined from uncomfortable loudness levels and vibrotactile thresholds, and speech recognition scores were measured using normal-hearing subjects. Auditory performance in noise (Hearing in Noise Test) was measured in a limited sample of SSD subjects. Overall comfort, ease of insertion, and removal and visibility of the oral appliance in comparison with traditional hearing aids were measured using a rating scale.

RESULTS

The oral appliance produces forces that are far below those experienced by the teeth from normal functions or conventional dental appliances. The bone-conduction signal level can be adjusted to prevent tactile perception yet provide sufficient gain and output at frequencies from 250 to 12,000 Hz. The device does not damage tooth surfaces nor produce heat, can be inserted and removed easily, and is as comfortable to wear as traditional hearing aids. The new microphone location has advantages for reducing the auditory deficits caused by SSD, including the potential to provide spatial cues introduced by reflections from the pinna, compared with microphone locations for existing devices.

CONCLUSION

A new approach for SSD has been proposed that optimizes microphone location and delivers sound by bone conduction through a removable oral appliance. Measures in the laboratory using normal-hearing subjects indicate that the device provides useful gain and output for SSD patients, is comfortable, does not seem to have detrimental effects on oral function or oral health, and has several advantages over existing devices. Specifically, microphone placement is optimized for reducing the auditory deficit caused by SSD, frequency bandwidth is much greater, and the system does not require surgical placement. Auditory performance in a small sample of SSD subjects indicated a substantial advantage compared with not wearing the device. Future studies will involve performance measures on SSD patients wearing the device for longer periods.

Comparison of the audiologic results obtained with the bone-anchored hearing aid attached to the headband, the testband, and to the "snap" abutment

OBJECTIVES

1) To quantify the audiometric differences between the preoperative tests with the Bone-Anchored Hearing Aid (BAHA) attached to the headband or the testband and the final postoperative result with the BAHA positioned at the implanted abutment. 2) To compare the results obtained with the headband and the testband. 3) To quantify the magnitude of the damping through the skin for the BAHA placed at the testband (important for comparison with the implantable hearing aids).

STUDY DESIGN

Prospective.

SETTING

Tertiary otological referral centre.

PATIENTS

Ten adult (> or = 14 yr old) BAHA patients (6 male and 4 female subjects) with bilateral air-bone gaps of minimum 40-dB hearing loss and with more than 6 months of BAHA experience with the BAHA "Compact."

METHODS

Audiometric free-field thresholds and speech audiometry scores (Consonant-Vowel-Consonant lists, phonemic score) have been evaluated for 3 conditions: BAHA attached to the implanted "Snap" abutment, to the headband, or to the testband.

RESULTS

For frequencies 1 to 4 kHz, significant differences in the range of 5 to 20 dB were found between the BAHA coupled with the Snap abutment and the preoperative testing conditions with the BAHA positioned at the headband or the testband. These differences were also reflected in the speech audiometry with a difference in speech reception threshold of approximately 4 to 7 dB.

CONCLUSION

1) Significant differences in the audiometric thresholds and the speech understanding scores were found between the preoperative test conditions and the final postoperative result. 2) Audiometric results obtained with the headband and the testband are comparable; therefore, the more comfortable headband is also suitable for the preoperative audiologic evaluation. 3) The magnitude of the skin damping must be accounted for when referring to the audiometric results obtained with the BAHA attached to the testband or headband.

The Baha Softband. A new treatment for young children with bilateral congenital aural atresia

The Baha (bone-anchored hearing aid) Softband appears to be an effective mean of hearing rehabilitation for children with a congenital bilateral aural atresia who are too young for the amplification of a Baha on an implant. The aided hearing threshold with a Baha Softband is almost equal to that achieved with a conventional bone conductor. The speech development of the children studied with a Baha Softband is on a par with peers with good hearing.