The Merits of Bilateral Application of Middle Ear Implants in Patients With Bilateral Conductive and/or Mixed Hearing Loss.

This study investigated sound localization abilities in patients with bilateral conductive and/or mixed hearing loss (BCHL) when listening with either one or two middle ear implants (MEIs). Sound localization was measured by asking patients to point as quickly and accurately as possible with a head-mounted LED in the perceived sound direction. Loudspeakers, positioned around the listener within a range of +73°/-73° in the horizontal plane, were not visible to the patients. Broadband (500 Hz-20 kHz) noise bursts (150 ms), roved over a 20-dB range in 10 dB steps was presented. MEIs stimulate the ipsilateral cochlea only and therefore the localization response was not affected by crosstalk. Sound localization was better with bilateral MEIs compared with the unilateral left and unilateral right conditions. Good sound localization performance was found in the bilaterally aided hearing condition in four patients. In two patients, localization abilities equaled normal hearing performance. Interestingly, in the unaided condition, when both devices were turned off, subjects could still localize the stimuli presented at the highest sound level. Comparison with data of patients implanted bilaterally with bone-conduction devices, demonstrated that localization abilities with MEIs were superior. The measurements demonstrate that patients with BCHL, using remnant binaural cues in the unaided condition, are able to process binaural cues when listening with bilateral MEIs. We conclude that implantation with two MEIs, each stimulating only the ipsilateral cochlea, without crosstalk to the contralateral cochlea, can result in good sound localization abilities, and that this topic needs further investigation.

Long-term follow-up and review of the Bone Conduction Implant.

Active transcutaneous bone conduction devices are a type of bone conduction device developed to keep the skin intact and provide direct bone conduction stimulation. The Bone Conduction Implant (BCI) is such a device and has been implanted in 16 patients. The objective of this paper is to give a broad overview of the BCI development to the final results of 13 patients at 5-year follow-up. Follow-up of these patients included audiological performance investigations, questionnaires, as well as safety evaluation and objective functionality testing of the device. Among those audiological measurements were sound field warble tone thresholds, speech recognition threshold (SRT), speech recognition score (SRS) and signal to noise ratio threshold (SNR-threshold). The accumulated implant time for all 16 patients was 113 years in February 2022. During this time, no serious adverse events have occurred. The functional improvement for the 13 patients reported in this paper was on average 29.5 dB (average over 0.5, 1, 2 and 4 kHz), while the corresponding effective gain was -12.4 dB. The SRT improvement was 24.5 dB and the SRS improvement was 38.1%, while the aided SNR-threshold was on average -6.4 dB. It was found that the BCI can give effective and safe hearing rehabilitation for patients with conductive and mild-to-moderate mixed hearing loss.

Systematic and audiological indication criteria for bone conduction devices and active middle ear implants.

Certain patients with conductive or mixed hearing loss can benefit from bone-conduction hearing devices or active middle ear implants. Available devices differ in coupling site, energy transfer from the sound processor to the implant, and the active or passive actuator technology. The audiological benefit of those devices depends on the maximum stable power output and the noise floor of the device, the degree and expected stability of the sensorineural hearing loss and the coupling efficiency with the aim on achieving a minumum of 30-35 dB effective dynamic range. The choice of the device is often a trade-off between the optimal audiological solution with respect to the hearing loss, technical device-related parameters and the expected coupling efficiency, the optimal surgical solution with respect to patho-anatomical aspects, device dimensions and the coupling site, invasiveness or surgical risks, and other patient factors with respect to the patients' wish and expectations, social aspects, device usability and connectivity. This review article lists all currently available implantable and conventional bone-conduction hearing devices and active middle ear implants with respect to technical features like maximum power output, market availability, and the expected effective output dynamic range.

Long-Term Stability and Safety of the Soundbridge Coupled to the Round Window.

OBJECTIVE: The objective of the study was to demonstrate the long-term outcomes of patients implanted with the active middle ear implant (AMEI) Vibrant Soundbridge (VSB) through coupling the floating mass transducer (FMT) to the round window (RW). METHODS: This retrospective study evaluated the short- and long-term clinical performance (audiological outcomes) and safety (revisions/explantations) of the VSB coupled to the RW between 2013 and 2019 at the St. Pölten University Hospital, Austria. For the outcome analysis, the sample was divided into a short-term examination group followed up for less than 12 months (<12 months) and a long-term examination group followed up for more than 12 months (>12 months). Cumulative survival outcomes were separately analyzed for subjects with and without cholesteatoma. RESULTS: 46 patients with an average long-term follow-up period of 31.43 months (13-75 months) were investigated. Complications requiring revision surgery were reported in total in seven patients with cholesteatoma (15.2%) and none in subjects without cholesteatoma (0%). Residual hearing was not affected by VSB surgery. Word understanding on the Freiburger monosyllabic speech test improved significantly at 65 dB (P < .0001) and 80 dB (P < .0001), and these outcomes were stable for long-term follow up. CONCLUSION: The VSB coupled to the RW is a safe implantation method for patients with conductive or mixed hearing loss. Hearing improvement was stable for the long-term follow-up up to 74 months. The revision rates are directly related to the underlying pathology of cholesteatoma (with radical cavity); thus, this special cohort requires additional counseling on potential complications. LEVEL OF EVIDENCE: 4 (Case-series) Laryngoscope, 131:E1434-E1442, 2021.

Implantation of a new active bone conduction hearing device with optimized geometry.

Here, we describe the surgical technique for implanting a new, active, transcutaneous bone conduction hearing aid. The implant technology is based on a system that has been in use reliably since 2012. The geometry of the new implant has been adapted based on experience with previously introduced implants. The surgery was feasible, standardized, and safe. Due to the optimized geometric design that improved the bone fit, it is not necessary to use specialized, detailed preoperative planning, except in challenging anatomical conditions; e.g., in young children, malformations, poor pneumatization, or after a canal wall down mastoidectomy.

Association of rheumatoid arthritis with hearing loss: a systematic review and meta-analysis.

Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting up to 1% of the worldwide population. RA is associated with multiple extra-articular manifestations (EAMs). Middle ear, cochlea and the auditory nerve are suspected sites of RA activity and hearing loss is a possible novel EAM of RA. Objective was to investigate the association of RA with the different subtypes of hearing loss. This systematic review was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted and the I2 was used to assess heterogeneity. Twelve studies comprising 20,022 RA patients and 79,244 controls were included in this systematic review. All studies were observational and were rated to a moderate rate of bias. RA patients had nearly fourfold increased odds of sensorineural hearing loss (SNHL) compared with controls (OR 3.42; 95% CI 2.50-4.69; I2 = 13). RA patients also had a significantly increased risk of SNHL (RR 2.28; 95% CI 1.88-2.76; I2 = 0). RA patients did not have increased odds of conductive hearing loss (CHL) and mixed hearing loss (MHL) (OR 1.36; 95% CI 0.52-3.55; I2 = 22); (OR 2.73; 95% CI 0.78-9.58; I2 = 0%). RA is significantly associated with SNHL. RA is not associated with CHL and MHL. Early screening of RA patients with pure tone audiometry should be considered.

Effects of the Conductive Component of Hearing Loss on Speech Discrimination Ability.

OBJECTIVES: Effects of decreasing auditory activity on speech discrimination ability are not fully understood. To investigate influence of decrease in auditory activity due to conductive and sensorineural components of hearing loss (HL) on speech discrimination ability. MATERIALS AND METHODS: We retrospectively reviewed medical records of patients with suspected HL at Kitasato University Hospital in 2017 and 2018. Patients were divided according to pure-tone audiometry findings: no HL (N-HL), conductive HL (C-HL), sensorineural HL (S-HL), and mixed HL (M-HL) groups. RESULTS: In total, 149 patients (224 ears) were eligible. The maximum speech discrimination score (SDSmax) for all ears significantly negatively correlated with age (r = -0.29, p<0.0001) and bone conduction (BC) threshold (r = -0.55, p<0.0001). For patients aged <50 years in N-HL and C-HL groups, SDSmax was nearly 100%, with no significant difference. SDSmax was significantly lower for older patients (≥50 years) in the M-HL group than in the S-HL group, even though there were no significant differences in age and BC thresholds between groups. CONCLUSION: Decrease of auditory activity due to the conductive component of M-HL may worsen speech discrimination ability. Early treatment of M-HL would be desirable for the preservation of auditory function.

Isolated Congenital Middle Ear Malformations: Comparison of Preoperative High-Resolution CT and Surgical Findings.

OBJECTIVES: To compare preoperative temporal bone high-resolution computed tomography (HRCT) readings to intraoperative findings during exploratory tympanotomy for suspected cases of isolated congenital middle ear malformations (CMEMs) and summarize the malformations that can and cannot be diagnosed with HRCT. METHODS: A retrospective study was conducted. All cases were confirmed as isolated CMEMs during surgery. Detailed clinical records were reviewed, with a focus on imaging and surgical findings. RESULTS: One hundred and thirty-two patients and 145 ears were reviewed. Ninety cases (62.1%) could be identified as isolated CMEMs and at least one as middle ear anomaly using preoperative HRCT. Fifty-five cases (37.9%) were reported to be completely normal and the patients underwent exploratory tympanotomy to determine the final diagnosis. Stapes fixation, either alone or associated with other ossicular chain anomalies, contributed to 53.1% of the cases. Most cases of aplasia or dysplasia of the ossicular chain, for example, aplasia/dysplasia of the long process of the incus, aplasia of the stapes' superstructure, and atresia of the oval window were easily identified in preoperative HRCT. However, fixation of the ossicular chain can be elusive in HRCT, and exploratory tympanotomy is needed for a definitive diagnosis. CONCLUSIONS: HRCT provides helpful preoperative clinical information in CMEM and may obviate the need for middle ear exploration in some cases. The negative findings (anomalies that are difficult to identify through preoperative HRCT) and the positive findings (anomalies that are relatively easy to identify through preoperative HRCT) were summarized.

Minimal invasive pocket technique for magnet bone implant hearing aid without fixation.

INTRODUCTION: The BAHA (bone-anchored hearing aid) Attract is a magnetic transcutaneous bone conduction device anchored into the temporal bone. The standard surgical technique for BAHA Attract is a multi-tools time-consuming process, which requires a large cutaneous incision. The objective of this study is to describe and test the feasibility of a minimally invasive pocket (MIP) technique for Magnet Bone Implant Hearing Aid (MBIHA) with a modified magnet of BAHA Attract without fixation and without any tissue reduction. We use a 3-cm vertical skin incision and a subperiosteal pocket. METHOD: A study of 10 patients with conductive or mixed hearing loss who benefited from a MBIHA using the MIP technique is presented. The pure tone average (PTA) (dB) for air-conduction thresholds and the speech recognition threshold (SRT) (dB) in speech audiometry in quiet are calculated. The Entific Medical Systems (EMS) questionnaire and the postoperative clinical outcomes are realized. RESULTS: We found a significant improvement of 33.8 dB on average for the PTA and 44.8 dB for the SRT with MBIHA at 3 months, compared with unaided situation. No implant was removed or displaced after 2 years of follow-up. The skin condition remains intact in all the cases. CONCLUSION: The minimally subperiosteal pocket surgical technique MIP without fixation and with tissue preservation for the MBIHA is safe, rapid and effective for patients with conductive or mixed hearing loss. It opens new perspectives of development and modify conventional concept in magnetic coupling of bone-conducted device.

The vibrating ossicular prosthesis in children and adolescents: a retrospective study.

PURPOSE: The primary objective of the retrospective study was to collect speech intelligibility data on children and adolescents implanted with the vibrating ossicular prosthesis (VORP) 503. METHODS: This was a retrospective, multicentre study on 55 children and adolescents from 6 German clinics aged between 5 and 17 years suffering from mixed or conductive hearing loss implanted with a VORP 503. Pre- and postoperative bone-conduction pure tone thresholds were measured at 0.5, 1, 2 and 4 kHz, and word recognition scores in the unaided and VORP 503-aided conditions using monosyllabic speech intelligibility tests measured at 65-dB sound pressure level (SPL) were determined. RESULTS: Mean pre- and postoperative bone-conduction thresholds remained unchanged, showing the preservation of inner ear hearing. Speech intelligibility assessed in quiet at 65-dB SPL improved on average from 24.5% (SD ± 25.4) unaided to 86.4% (SD ± 13.4) aided. The average improvement of 61.9% (SD ± 25.3) was clinically and statistically significant. A total of three complications were found in the medical records of 55 subjects. The responsible investigators judged these events as procedure related. CONCLUSION: The treatment of children suffering from conductive or mixed hearing loss with the VORP 503 implant demonstrates excellent aided benefit in terms of speech understanding and only minor complications.

Comparison of two different bone anchored hearing instruments: Baha-5 vs Ponto-plus.

BACKGROUND: To our knowledge, there is no study comparing Ponto Plus® (Oticon Medical AB, Askim, Sweden) and Baha® 5 (Cochlear Bone Anchored Solutions AG, Mölnlycke, Sweden) available in the literature. AIMS/OBJECTIVES: The primary aim was to compare the performance of the Baha 5 with the Ponto Plus device in terms of speech understanding in quiet and in noise. In addition, to determine statistically whether or not the difference between the abutment systems created any variation in terms of skin reaction. MATERIALS AND METHODS: Twenty bone-anchored hearing instrument users, ten in each group, were evaluated for speech understanding in quiet and several signal-to-noise ratios using the Turkish Matrix Test in a two-speaker setup. The Holger classifications were also reviewed to determine adverse skin reactions. RESULTS: It was revealed that the hearing results of both devices were similar and, when the skin reactions were compared, there was no statistically significant difference between the two-implant systems. CONCLUSIONS AND SIGNIFICANCE: Because of the similar results of the groups, it can be interpreted as the key different device features such as the size, weight, colour alternatives, and the ease of use of the devices might be important in terms of device preference.

Hearing Loss in Pediatric Septo-Optic Dysplasia.

OBJECTIVE: To identify and characterize hearing loss (HL) in children with septo-optic dysplasia (SOD). METHODS: Otologic and audiometric data for patients less than 18 years of age identified as having SOD who were seen in the Children's Healthcare of Atlanta-Scottish Rite Hospital clinic between 2013 and 2017 were collected and reviewed through a HIPAA-compliant medical record search. Relevant literature was also reviewed with the assistance of Medline. RESULTS: Sixty-four patients with SOD were identified, and 7 of those patients (10.9%) were diagnosed with hearing loss. Type of hearing loss was sensorineural (SNHL) in 5 patients (63%), mixed (MHL) in 1(14%), and conductive (CHL) in 1(14%). Bilateral loss presented in 60% (3/5) of SNHL patients, while the rest demonstrated unilateral loss. Unilateral findings included cochlear nerve deficiency (1) and atresia/microtia (1). Tympanostomy tubes were required in 57% (4/7) of SOD children with hearing loss. Amplification was successfully implemented in 86% (6/7). CONCLUSIONS: Hearing loss was found in nearly 11% of SOD children, and SNHL was identified as (63%) the predominant form of loss. To our knowledge, this is the first retrospective review of hearing loss in a pediatric SOD cohort and the first to report of cochlear nerve deficiency and atresia/microtia in this population. Based on these findings, early identification of hearing loss with imaging when appropriate and treatment of otitis in this population is recommended.

[An acute acoustic injury during the early postoperative period following stapedoplasty]. / Ostraia akusticheskaia travma v rannem posleoperatsionnom periode posle stapedoplastiki.

This article was designed to report a clinical case of an acute acoustic injury inflicted by a discharge of the lightning ball during the early postoperative period in a female patient following surgical stapedoplasty. The acoustic impact resulted in a marked deterioration of hearing in the operated ear with simultaneous elevation of the threshold of bone sound conduction to above the preoperative value. It is concluded that the patients who had undergone the stapedoplastic surgical intervention should be advised to avoid strong acoustic impacts during the postoperative period.

Auditory System Involvement in Psoriasis.

Psoriasis is a systemic inflammatory disorder associated with many other chronic and progressive diseases. There are few studies on the association of psoriasis with alterations in auditory function. A clinical and instrumental pilot study of auditory function was performed with 77 psoriatic patients and 77 age- and sex-matched healthy controls. The main results were: (i) hearing loss, mostly of sensorineural type, was significantly more frequent in patients than in controls; (ii) conductive and mixed hearing loss were more frequent in arthropathic than in non-arthropathic psoriatic patients; (iii) duration of psoriasis > 10 years or smoking were associated with higher frequency of hearing loss; (iv) psoriasis was more severe in patients with hearing loss than in those without hearing loss. Tympanogram abnormalities were found in patients more often than in controls. These data expand the list of extracutaneous conditions associated with psoriasis, and support the need for further basic and clinical research in this field.

Does hearing in response to soft-tissue stimulation involve skull vibrations? A within-subject comparison between skull vibration magnitudes and hearing thresholds.

Hearing can be elicited in response to bone as well as soft-tissue stimulation. However, the underlying mechanism of soft-tissue stimulation is under debate. It has been hypothesized that if skull vibrations were the underlying mechanism of hearing in response to soft-tissue stimulation, then skull vibrations would be associated with hearing thresholds. However, if skull vibrations were not associated with hearing thresholds, an alternative mechanism is involved. In the present study, both skull vibrations and hearing thresholds were assessed in the same participants in response to bone (mastoid) and soft-tissue (neck) stimulation. The experimental group included five hearing-impaired adults in whom a bone-anchored hearing aid was implanted due to conductive or mixed hearing loss. Because the implant is exposed above the skin and has become an integral part of the temporal bone, vibration of the implant represented skull vibrations. To ensure that middle-ear pathologies of the experimental group did not affect overall results, hearing thresholds were also obtained in 10 participants with normal hearing in response to stimulation at the same sites. We found that the magnitude of the bone vibrations initiated by the stimulation at the two sites (neck and mastoid) detected by the laser Doppler vibrometer on the bone-anchored implant were linearly related to stimulus intensity. It was therefore possible to extrapolate the vibration magnitudes at low-intensity stimulation, where poor signal-to-noise ratio limited actual recordings. It was found that the vibration magnitude differences (between soft-tissue and bone stimulation) were not different than the hearing threshold differences at the tested frequencies. Results of the present study suggest that bone vibration magnitude differences can adequately explain hearing threshold differences and are likely to be responsible for the hearing sensation. Thus, the present results support the idea that bone and soft-tissue conduction could share the same underlying mechanism, namely the induction of bone vibrations. Studies with the present methodology should be continued in future work in order to obtain further insight into the underlying mechanism of activation of the hearing system.

Long-Term Outcomes of Vibroplasty Coupler Implantations to Treat Mixed/Conductive Hearing Loss.

OBJECTIVE: To evaluate the long-term safety and performance of four different vibroplasty couplers (round window, oval window, CliP and Bell coupler) in combination with an active middle ear implant. METHODS: This was a multicentre, prospective, long-term study including 5 German hospitals. Thirty adult subjects suffering from conductive or mixed hearing loss were initially enrolled for the study, 24 of these were included in the final analysis with up to 36 months of postsurgical follow-up data. Bone conduction and air conduction were measured pre- and postoperatively to evalu ate safety. Postoperative aided sound field thresholds and Freiburger monosyllable word recognition scores were compared to unaided pre-implantation results to confirm performance. Additional speech tests compared postoperative unaided with aided results. To determine patient satisfaction, an established quality-of-life questionnaire developed for conventional hearing aid usage was administered to all subjects. RESULTS: Mean postoperative bone conduction thresholds remained stable throughout the whole study period. Mean functional gain for all couplers investigated was 38.5 ± 11.4 dB HL (12 months) and 38.8 ± 12.5 dB HL (36 months). Mean word recognition scores at 65 dB SPL increased from 2.9% in the unaided by 64.2% to 67.1% in the aided situation. The mean postoperative speech reception in quiet (or 50% understanding of words in sentences) shows a speech intelligibility improvement at 36 months of 17.8 ± 12.4 dB SPL over the unaided condition. The signal-to-noise ratio (SNR) improved by 5.9 ± 7.2 dB SNR over the unaided condition. High subjective device satisfaction was reflected by the International Inventory for Hearing Aids scored very positively. CONCLUSION: A significant improvement was seen with all couplers, and audiological performance did not significantly differ between 12 and 36 months after surgery.

A multicenter study on objective and subjective benefits with a transcutaneous bone-anchored hearing aid device: first Nordic results.

Examination of objective as well as subjective outcomes with a new transcutaneous bone-anchored hearing aid device. The study was designed as a prospective multicenter consecutive case-series study involving tertiary referral centers at two Danish University Hospitals. A total of 23 patients were implanted. Three were lost to follow-up. Patients had single-sided deafness, conductive or mixed hearing loss. INTERVENTION: Rehabilitative. Aided and unaided sound field hearing was evaluated objectively using (1) pure warble tone thresholds, (2) pure-tone average (PTA4), (3) speech discrimination score (SDS) in quiet, and (4) speech reception threshold 50% at 70 dB SPL noise level (SRT50%). Subjective benefit was evaluated by three validated questionnaires: (1) the IOI-HA, (2) the SSQ-12, and (3) a questionnaire evaluating both the frequency and the duration of hearing aid usage. The mean aided PTA4 was lowered by 14.7 dB. SDS was increased by 37.5% at 50 dB SPL, SRT50% in noise improved 1.4 dB. Aided thresholds improved insignificantly at frequencies above 2 kHz. 52.9% of the patients used their device every day, and 76.5% used the device at least 5 days a week. Mean IOI-HA score was 3.4, corresponding to a good benefit. In SSQ-12, "quality of hearing" scored especially high. Patients with a conductive and/or mixed hearing loss benefitted the most. This device demonstrates a significant subjective hearing benefit 8 month post surgery. In patients with conductive and/or mixed hearing losses, patient satisfaction and frequency of use were high. Objective gain measures showed less promising results especially in patients with single-sided deafness (SSD) compared to other bone conduction devices.

Identification of induced and naturally occurring conductive hearing loss in mice using bone conduction.

While many mouse models of hearing loss have been described, a significant fraction of the genetic defects in these models affect both the inner ear and middle ears. A common method used to separate inner-ear (sensory-neural) from middle-ear (conductive) pathologies in the hearing clinic is the combination of air-conduction and bone-conduction audiometry. In this report, we investigate the use of air- and bone-conducted evoked auditory brainstem responses to perform a similar separation in mice. We describe a technique by which we stimulate the mouse ear both acoustically and via whole-head vibration. We investigate the sensitivity of this technique to conductive hearing loss by introducing middle-ear lesions in normal hearing mice. We also use the technique to investigate the presence of an age-related conductive hearing loss in a common mouse model of presbycusis, the BALB/c mouse.

Audiometric findings with voluntary tensor tympani contraction.

BACKGROUND: Tensor tympani contraction may have a "signature" audiogram. This study demonstrates audiometric findings during voluntary tensor tympani contraction. METHODS: Five volunteers possessing the ability to voluntarily contract their tensor tympani muscles were identified and enrolled. Tensor tympani contraction was confirmed with characteristic tympanometry findings. Study subjects underwent conventional audiometry. Air conduction and bone conduction threshold testing was performed with and without voluntary tensor tympani contraction. MAIN OUTCOME MEASURE: Changes in air conduction and bone conduction thresholds during voluntary tensor tympani contraction. RESULTS: Audiometric results demonstrate a low frequency mixed hearing loss resulting from tensor tympani contraction. Specifically, at 250 Hz, air conduction thresholds increased by 22 dB and bone conduction thresholds increased by 10 dB. CONCLUSIONS: Previous research has demonstrated a low frequency conductive hearing loss in the setting of tensor tympanic contraction. This is the first study to demonstrate a low frequency mixed hearing loss associated with tensor tympani contraction. This finding may aid in the diagnosis of disorders resulting from abnormal tensor tympani function. Tensor tympani contraction should be included on the differential for low frequency mixed hearing loss.

An Implantable Hearing System As Rehabilitation for Hearing Loss Due to Bilateral Aural Atresia: Surgical Technique and Audiological Results.

OBJECTIVE: To demonstrate the surgical technique and audiological results of a middle ear implant for restoring hearing in patients with bilateral aural atresia and microtia with conductive or mixed hearing loss. MATERIALS AND METHODS: In this prospective study, 12 subjects aged 12 years and older presenting with hearing loss and bilateral congenital aural atresia underwent surgical insertion of a middle ear implant. The patients underwent tympanomastoidectomy with a wide opening of the attic and preservation of the roof of the atresic tympanic bone to expose the middle ear and position the floating mass transducer of the implant. RESULTS: There were no intraoperative or postoperative complications. The hearing threshold averages in a free field were 53.5 dB preoperatively and 25.6 dB postoperatively. Monosyllabic word recognition averaged 61% preoperatively and 91.3% postoperatively. The average speech perception in quiet conditions during the hearing in noise test improved from 67.11 dB to 45.99 dB, and the signal-to-noise ratio improved from 5.64 to 1.31. CONCLUSION: The tested system is an excellent option for auditory rehabilitation of conductive hearing loss due to bilateral ear atresia. The surgery is well structured and safe and provides several alternatives to the surgeon, which is valuable in difficult cases.