Medical Policy

This document addresses the use of semi-implantable and fully implantable middle ear hearing aids for the treatment of moderate to severe sensorineural hearing loss and for all other proposed uses.

Note: Benefit language supersedes this document. Hearing aids are not a covered benefit under all member contracts/certificates. Please see the text in the footnote of this document regarding Federal and State mandates and contract language, as these requirements or documents may specifically address the topic of hearing aids.

Note: Please see the following documents related to the treatment of hearing loss:

• CG-DME-37 Air Conduction Hearing Aids
• CG-SURG-81 Cochlear Implants and Auditory Brainstem Implants
• CG-SURG-82 Bone-Anchored and Bone Conduction Hearing Aids

Note: For a high-level overview of this document, please see “Summary for Members and Families” below

Investigational and Not Medically Necessary:

Semi-implantable and fully implantable middle ear hearing aids are considered investigational and not medically necessary for all indications.

This document describes clinical studies and expert recommendations, and explains why we do not consider implantable middle ear hearing aids to be clinically appropriate. The following summary does not replace the medical necessity criteria or other information in this document. The summary may not contain all of the relevant criteria or information. This summary is not medical advice. Please check with your healthcare provider for any advice about your health.

Key Information

The middle ear is the space behind the eardrum that contains three small bones (the malleus, incus, and stapes). These bones move in response to sound and help transmit vibrations from the eardrum to the inner ear. In normal hearing, sound travels through the ear canal, causes the eardrum to vibrate, and these vibrations are passed through the middle ear bones to the inner ear.

Problems in the middle ear can interfere with this process. Conditions such as fluid buildup, infection, or abnormalities of the middle ear bones can prevent sound from being transmitted effectively. When people with these conditions do not get adequate help from hearing aids, some have proposed treatments that aim to bypass or directly stimulate the middle ear structures, but these approaches have not been shown to consistently improve hearing compared to standard options.

Implantable middle ear hearing aids are devices proposed for placement partly or fully inside the ear to help adults with moderate to severe hearing loss, especially when standard hearing aids worn outside the ear do not work well or cannot be tolerated. Some devices are partly implanted, with parts of the device surgically placed in the middle ear and other parts used outside the body, for example, the Vibrant Soundbridge (VSB) and Maxum devices. Other such devices are fully implanted, such as Esteem (Envoy Medical). These devices send sound vibrations directly to the bones of the middle ear instead of using air to carry sound. Studies show that while many people report better sound quality or comfort, these devices usually do not improve hearing more than standard hearing aids. There are also risks, such as pain, infections, device failure, or nerve problems such as facial weakness or changes in taste. Based on current evidence, these devices are not considered clinically appropriate for any use because they have not been shown to improve health and the risks involved in their use do not outweigh their potential benefits.

What the Studies Show

Most studies of these devices are small, short-term, or are not carefully designed/controlled to ensure reliable results. These studies show that:

• Hearing results are often similar to standard hearing aids, but not better.
• Many studies are small, short, or were not carefully managed to ensure reliable results.
• Some people do not gain meaningful benefit, and a few may have worse results.
• There are risks, including surgical complications, device failure, and nerve injury.

Is this clinically appropriate?

Implantable middle ear hearing aids, including Vibrant Soundbridge, Maxum, and Esteem, are not clinically appropriate because they have not been proven to improve health and the risks involved in their use do not outweigh their possible benefits.

Because of these limits, implantable middle ear hearing aids are not clinically appropriate in any situation at this time.

(Return to Description/Scope)

Summary

Implantable middle ear hearing aids are an alternative to conventional hearing aids for adults with moderate to severe sensorineural hearing loss who cannot tolerate or benefit from external devices. Semi-implantable systems, Vibrant Soundbridge and the Maxum, mechanically stimulate the ossicular chain. The Esteem, a fully implantable system, uses internal transducers and the native ear structures to process sound. These devices are FDA approved for sensorineural hearing loss but not for conductive or mixed hearing loss.

Overall, the evidence base is limited and characterized by small, nonrandomized studies with short follow-up and heterogeneous outcome measures. While improvements in functional gain and patient-reported satisfaction are frequently reported, objective outcomes such as speech recognition are generally comparable to conventional hearing aids, and consistent, clinically meaningful superiority has not been demonstrated.

Systematic reviews highlight moderate-to-poor study quality and a lack of robust long-term data to establish durability or net health benefit. Evidence for use in anatomic or conductive conditions is particularly limited to small case series without appropriate comparators. Although the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) suggest these devices may be considered in carefully selected individuals who cannot benefit from conventional hearing aids, this position is based largely on limited and older evidence and does not establish a standard of care.

Description

Semi-Implantable Middle Ear Hearing Aids for Bilateral Moderate to Severe Sensorineural Hearing Loss

The efficacy of the semi-implantable middle ear hearing aid was studied by comparing the results of pre- and postimplant audiometric tests and audiologic questionnaires. Additional outcome measures included satisfaction with fit and comfort and with the quality and clarity of sound. Individual preference for an implantable middle ear hearing aid compared to an externally worn hearing aid was considered, however, it must be determined to what extent individual preference is based on convenience compared to preference based on improved hearing.

In 2000, the Vibrant Soundbridge^™ (VSB) (MED-EL Corporation, Durham, NC) device received premarket approval (PMA) by the U.S. Food and Drug Administration (FDA) to treat moderate to severe sensorineural hearing loss in adults who desire an alternative to an acoustic hearing aid. In FDA PMA clinical trial data, VSB implantation was associated with 55 adverse events in 81 individuals (68%) across three studies. The most common complications were ear fullness (22%), transient pain (16%), and altered taste (8.6%), most of which were temporary. Implant failure requiring removal or reimplantation occurred in 7.4%, all involving an older device version no longer in use.

Luetje (2002) conducted the VSB pivotal trial, a prospective, multicenter, single-subject (self-controlled) Phase III study which included 53 adults with moderate to severe sensorineural hearing loss. The study showed significant improvements in functional gain and patient-reported satisfaction, with speech recognition comparable to conventional hearing aids and minimal impact on residual hearing. Key limitations include the nonrandomized design, short follow-up (approximately 3 to 5 months), and reliance on subjective outcomes, limiting conclusions on long-term benefit and comparative effectiveness.

In the early European trials of semi-implantable middle ear hearing aids, the studies included overlapping populations of individuals from many of the same institutions where each individual served as their own control. A feasibility study by Fisch (2001) reported detailed steps of the implantation of the VSB and evaluated the impact of surgery on residual hearing. A total of 47 participants had a successful implantation, however, the study did not report outcomes in detail but suggested that implantation was feasible with relatively few surgical complications and little change in severity of hearing impairment. A subsequent multicenter study conducted by Fraysee (2001) reported audiometric results for 25 participants who underwent implantation at several French medical centers. The authors reported that the Soundbridge (model D) semi-implantable middle ear hearing aid provided “significantly superior” functional gain than conventional hearing aids. The VSB implantation procedure did not affect the residual hearing level in the implanted ear, nor did it present any unacceptable risk. The authors concluded that the measurable benefit from VSB in comparison with conventional amplification was demonstrated with regard to the provision of superior usable amplification and greater ease in communication in daily listening environments for the majority of individuals. However, they suggested “A longitudinal study beyond 3 months may help to resolve some of the unanswered questions with regard to the long-term effects and benefits of the VSB for the adults with hearing impairments.”

Tysome (2010) systematically reviewed 17 studies comparing hearing improvements for middle-ear hearing implants to conventional hearing aids. The authors noted high-quality, long-term studies are not available and that the quality of included studies was moderate to poor. They noted hearing gains with middle ear hearing aid implants were comparable to gains with conventional hearing aids and may even improve sound quality and speech perception. Furthermore, they noted the evidence did not demonstrate a decrease in residual hearing. However, the authors recommend that additional study with long-term results is required to compare middle ear hearing implants with conventional hearing aids.

Müller (2025) conducted a single-center comparative study evaluating audiologic and spatial hearing outcomes in adults with unilateral conductive or combined hearing loss treated with implantable hearing devices, specifically the VSB active middle ear implant versus a bone conduction implant. The study included 13 individuals with VSB implants and 8 with bone conduction implants. Participants were assessed for speech intelligibility, sound localization, and patient-reported outcomes after at least several months of use. Results demonstrated that both implantable hearing systems provided comparable improvements in audiometric thresholds and speech understanding, with no statistically significant differences between groups. There was a consistent trend toward improved speech intelligibility, directional hearing, and patient-reported benefits in the VSB group. Sound localization remained impaired compared with normal hearing controls in both groups, though VSB users showed a tendency toward lower localization errors. The authors emphasized that while implantable hearing aids can effectively rehabilitate hearing by bypassing middle ear pathology and providing direct stimulation to the inner ear, the overall evidence is limited by small sample size, lack of significant differences between device types, and persistent deficits in binaural hearing outcomes, highlighting the need for larger, controlled studies to better define the comparative clinical benefit of implantable hearing technologies. The evidence in the peer-reviewed literature regarding health outcomes achieved through use of the VSB is inconsistent and the FDA did not allow the manufacturer of the hearing aid to claim superiority to standard hearing aids in product labeling indications. In the data that accompanied the clinical studies presented to the FDA, most study participants were satisfied or very satisfied with the VSB implant (83% to 98%) and 91% reported the hearing aid was beneficial. In one study the expected hearing gains were not achieved in 52% of the participants (Snik, 2001). In addition, while residual hearing was not affected in most individuals (90% to 96%), in one study residual hearing decreased in 13% of individuals (Luetje, 2002). Most of the study participants preferred the VSB implant compared to the previously used conventional air conduction hearing aids; however, audiometric parameters such as functional gain and word recognition were not significantly improved for semi-implantable middle ear hearing aids compared to conventional hearing aids in all studies (Schmuziger, 2006; Sterkers, 2003; Verhagen, 2008). Additional studies with appropriate controls, adequate power, and long-term follow-up are needed before reasonable conclusions can be made regarding net health outcomes of VSB implants compared to externally worn hearing aids.

A second semi-implantable device, the Maxum^® Hearing Implant System (Ototronix, LLC, Houston, TX), was approved in 2001 under the name SOUNDTEC^® Direct System^™. The device is approved for individuals with moderate to severe sensorineural hearing loss who desire an alternative to an acoustic hearing aid. The original approval is based on the results of a multicenter, single-arm, phase II trial of 103 individuals. The primary efficacy endpoint was set as the functional gain achieved comparing an optimally fitted hearing aid to that obtained with the semi-implanted device at approximately 20 weeks post implantation. Results showed modest objective benefits, including approximately 7-8 dB functional gain and mixed improvements in speech recognition, with more consistent gains in high-frequency hearing. Key limitations include the lack of randomization or control group, modest effect size, small sample and limited long-term follow-up, restricted generalizability.

An analysis of audiologic data from a multicenter prospective Phase III FDA clinical trial evaluated factors associated with benefit of a unilateral Maxum Hearing Implant compared to conventional hearing aids. The clinical data of 91 individuals with a greater than 2 year history of bilateral, non-fluctuating sensorineural hearing loss. The primary outcome was word recognition in quiet, measured under multiple conditions (unaided, hearing aid-aided, and implant-aided). Most individuals demonstrated improvement with both hearing aids (95.6%) and the implant (98.0%) compared to unaided performance. The overall improvement with the implant over hearing aids was modest, with mean word recognition scores only slightly higher (81.8% vs. 77.6%). Notably, only a small subset of individuals (16 of 91) showed a statistically significant improvement with the implant over hearing aids, while others experienced similar outcomes between devices, and a small number had no benefit or even decreased performance after implantation. The authors concluded that while the implant can improve speech recognition, the degree of additional benefit over conventional hearing aids is variable and often limited. Limitations include testing conducted only in quiet conditions, which may not reflect real-world performance, potential selection bias, and limited generalizability due to evaluation of a single device in a specific population. Overall, the findings suggest that while the device may provide benefit in some cases, consistent and clinically meaningful superiority over conventional hearing aids has not been clearly established.

Semi-Implantable Middle Ear Hearing Aids for Hearing Loss from Anatomic and other Medical Conditions

Semi-implantable middle ear hearing aids have been proposed as a treatment option for hearing loss due to congenital anatomic abnormalities, such as microtia, aural atresia, and ossicular chain malformations, particularly when conventional air-conduction hearing aids are not feasible because of absent ear canals, chronic infection, or distorted anatomy. These devices may offer theoretical advantages by directly stimulating middle ear or cochlear structures and bypassing the conductive pathway. However, the current evidence base supporting their medical necessity remains limited. Kiefer (2006) describes feasibility and favorable outcomes in a single case combining auricular reconstruction with implantation, but such findings are not generalizable. Subsequent small cohort studies (Frenzel, 2009; Thomas, 2017) report improvements in hearing thresholds and speech perception, yet are constrained by small sample sizes, lack of control groups, and limited long-term data. Other investigations have identified procedural limitations and complications depending on technique (Zwartenkot, 2011). Additional small case series evaluating alternative coupling approaches, including round window applications, have been reported (Colletti, 2011; Colletti, 2013; Mandallà, 2011) as well as studies in conductive or mixed hearing loss populations who may not benefit from conventional amplification (Marino, 2013; Iwasaki, 2017); however, these studies are limited by small sample sizes, missing data, and lack of comparator groups.

More recent evidence continues to reflect these limitations. A retrospective cohort of 10 individuals (12 ears) with congenital aural atresia demonstrated improved hearing thresholds and reported satisfaction following implantation, but emphasized that studies in this population are typically very small and heterogeneous, limiting meaningful comparisons and generalizability. Similarly, small retrospective studies such as Catisquini (2025) which evaluated use in 9 individuals, show short-term improvements in hearing and speech perception that stabilize over a few months, but are limited by sample size and short follow-up. Overall, the literature continues to be characterized by small, non-randomized studies, inconsistent methodologies, and a lack of high-quality comparative trials.

The current evidence is insufficient to establish consistent clinical benefit or long-term improvement from the use of middle-ear hearing aids.

Ernst (2016) performed a systematic review that evaluated outcomes in 19 studies (n=294 participants) of VSB system implants, 13 studies (n=666 participants) of bone conduction hearing implants, and 4 studies (n=43 participants) of middle ear surgery plus hearing aid outcomes in the treatment of conductive or mixed hearing loss. There were no studies directly comparing methods. The functional gains with the VSB at 3 months ranged from 12.5 to 43.4 dB hearing loss, averaging 29.6 dB. Significant improvements in speech recognition occurred, although methods of measuring speech differed across studies. In general, the VSB system was reported as safe and effective when compared to no intervention and bone conduction hearing aids. The authors conclude that VSB systems provided consistent hearing gain compared to middle ear surgery plus conventional hearing aids. Heterogeneous outcome measures across the studies made it difficult to summarize the data.

Kahue (2014) systematically reviewed the safety and efficacy of the FDA-approved middle ear implant systems then in use for the rehabilitation of sensorineural hearing loss. A total of 17 unique studies satisfied inclusion criteria and were evaluated for variables including functional gain, speech recognition score improvement, audiometric threshold shift following surgery, adverse events, and subject-reported outcome measures. Heterogeneous outcome reporting precluded meta-analysis; however, a structured review was performed using best available data. The authors reported that most studies evaluating the safety and efficacy of middle ear implants are retrospective in nature with limited follow-up.

Fully Implantable Middle Ear Hearing Aids

The Esteem Implantable Hearing System (Envoy Medical, White Bear Lake, MN), previously known as the Envoy^® System, received FDA approval in March 2010 through the PMA process as a fully implantable middle ear hearing aid “Intended to alleviate hearing loss in patients by replicating the ossicular chain and providing additional gain” in adults 18 years of age or older with stable bilateral sensorineural hearing loss (FDA, 2010). The PMA pivotal clinical trial (Trial 0204) was a prospective, multicenter, nonrandomized, single-arm study designed to evaluate the safety and effectiveness of the Esteem middle ear implantable (MEI) hearing aid. The study enrolled 62 individuals who acted as their own controls. A total of 61 participants were followed for 1 year. The implant had a 5% revision rate prior to the 4-month follow-up visit due to fibrotic tissue growth or interference. There were no revisions between the 4- and 10-month follow-up. Efficacy data was reported as statistically superior to the pre-implant hearing in two measures; however, the participants used different types of hearing aids before receiving their implant. Side effects associated with the implantation of the Esteem MEI included facial paralysis (7%) and taste disturbance (42%), the majority resolved during the 1-year study period.

Prior to FDA approval, two studies suggest that the Esteem MEI hearing aid may improve hearing outcomes in adults with moderate to severe sensorineural hearing loss, though with important limitations. In a prospective multicenter feasibility study of 7 participants, 5 had functioning devices at 2 months post-activation and demonstrated improved word recognition and perceived benefit, particularly in noise, compared to hearing aids. Functional gain and speech reception thresholds showed similar results to hearing aids. Early device failures were a major concern (Chen, 2004). In a separate case series of 6 participants with variable short-term follow-up, outcomes were mixed: some experienced transient postoperative hearing loss that resolved after activation, while others showed modest hearing gains and improved perceived sound quality (Barbara, 2009). Overall, the evidence is limited by small sample sizes, short follow-up, lack of control groups, subjective outcomes, and early device reliability issues.

Kraus (2011) reported on the 1-year follow-up results of the phase II FDA trial of the Esteem MEI study. A total of 57 individuals were implanted. These individuals all had bilateral mild to severe sensorineural hearing loss with discrimination > 40%. The Esteem MEIs were activated 2 months postimplant. Hearing results were compared with ipsilateral baseline unaided and aided scores. Speech reception thresholds improved 11.8 dB (± 1.8 dB) from a mean pre-implant aided score of 41.2 dB to 29.4 dB (p<0.001). At 12 months, the mean percentage improvement in word recognition scores was 19.8 (± 4.3) from pre-implant aided scores. Of the 52 participants included in the analysis, 32 (62%) improved, 14 (27%) were the same, and 6 (11%) were worse. The authors reported 133 adverse events or adverse device effects in 52 of 57 (91%) participants. These included 3 cases of facial paresis resolved with medication. Limitations of this study include those related to implantation of the Esteem MEI. A large facial recess is required due to the transducer size. Sacrifice of the chorda tympani nerve (CTN) was necessary in more than 60% of the implant cases. Functional gain will be limited if the CTN contacts the driver, the transducer vibrates the nerve, and vibrations are sensed by the sensor, thus creating a feedback loop. Additional limitations of this trial include non-blinded audiology assessments, lack of validated tests to measure clarity and fidelity, and lack of outcomes reported more than 12 months after implantation.

Additional studies with limited populations reporting short-term outcomes are available in the peer-reviewed literature. Barbara (2011) reported on the use of the Esteem MEI in a case series of 21 individuals with severe bilateral sensorineural hearing loss. The authors reported mean hearing threshold levels improved overall from 70 to 48 dB. Limitations of this case series include the reporting of short-term results from a small number of participants. Shohet (2011) reported on the follow-up of a subset of 5 individuals with profound hearing loss who were part of the initial FDA PMA trial. At 12 months, improvements in functional gain and word recognition scores were reported with use of the Esteem MEI.

Memari (2011) reported the results of a prospective nonrandomized controlled clinical trial that involved 10 individuals with moderate to severe sensorineural hearing loss who received the Esteem MEI. The average follow-up period was 29.4 months with each individual acting as their own control. A single Esteem MEI was explanted as a result of low hearing gain and facial weakness. One participant required revision due to excessive bone growth after insertion. Overall average hearing gain and subjective hearing quality based on preoperative and postoperative comparisons was reported by all except 1 individual. Lateral location of the facial nerve, sclerotic mastoid air cells, and narrow facial recess space appear to be associated with postoperative complications. The results of this study need confirmation in a larger trial.

Gerard (2012) reported the clinical outcomes of a small, retrospective MEI implant case series (n=13). A total of 5 minor complications occurred and 3 participants required revision surgery. Two individuals (15%) suffered major complications (wound infections) and their implants had to be removed 4 months postoperatively. Based on an abbreviated profile of hearing aid benefit (APHAB) questionnaire, 84% of the participants reported satisfaction and improvement in PTA gain and word recognition scores when compared to previous use with a conventional hearing aid. The authors acknowledge that careful selection of candidates is required and specialized skill and experience is needed to perform the procedure. This study is limited by its relatively small size and retrospective design.

Monini (2012) compared the performance of the Esteem MEI to use of a conventional hearing aid in 15 individuals with moderate to severe (n=8) or severe to profound (n=7) sensorineural hearing loss. The authors reported the Esteem MEI candidates were either unable to wear or had poor results with a conventional hearing aid or chose the Esteem MEI for aesthetic purposes. Reported outcomes included measurements of speech reception threshold and word recognition scores. Subjective benefit was evaluated by a Client Oriented Scale of Improvement (COSI) questionnaire. Although there were statistically significant differences between unaided and conventional hearing aid use and between unaided and Esteem MEI use, there was no statistically significant difference between the use of conventional hearing aids and the Esteem MEI. Limitations of this study include the limited sample of participants, lack of randomization, lack of reporting on adverse events, and lack of statistically significant outcome data to determine if the Esteem MEI offers superior performance when compared to conventional hearing aids for moderate-to severe or severe-to-profound sensorineural hearing loss.

Pulcherio (2014) reported results of a systematic review of 22 studies (n=244) of two fully-implantable middle-ear hearing devices, the FDA-approved Esteem MEI (n=134) and a fully implantable MEI under development, the Otologics Carina^® (n=110) (Otologics, LLC, Boulder, CO). No randomized controlled trials were identified; most studies included a small number of participants. The largest series included 57 individuals and 12 series included fewer than 10 participants. All of the studies showed improvement of sound field threshold from unaided to aided conditions with the fully implantable device, but the magnitude of the improvements varied. Several other case series have been published that do not provide significant additional evidence about outcome improvements associated with the Esteem MEI device. Barbara and colleagues (2014) reported on a case series (published since the Pulcherio and colleagues systematic review) where high rates of facial nerve palsies (10 of 34 participants [29.4%]) occurred and persisted to 3 months of follow-up in 6 of 34 individuals (17.6%) implanted with the Esteem MEI. Overall, studies related to fully implantable middle ear hearing aid devices report on short-term results from a small number of participants and demonstrate insufficient evidence to support the clinical utility of their use.

Shohet (2017) reported 5-year hearing outcomes of the Esteem MEI in a prospective, nonrandomized, multicenter post-market approval study conducted in the setting of private and hospital-based practices where each participant acted as their own control. A total of 51 participants with mild to severe sensorineural hearing loss were implanted between 2008 and 2009; 49 participants completed the 5-year study which included annual follow-up visits. The primary efficacy endpoints were speech reception threshold and word recognition scores at 50 dB. Secondary endpoints included adverse device effects, serious adverse device effects, and other parameters. The overall mean speech reception threshold scores demonstrated a significant improvement with the implant compared to the baseline aided condition through year 5. Additionally, a statistically significant mean difference between the baseline aided condition and implant speech reception threshold scores was demonstrated at each annual time interval (one-sample t-test; p<0.01). A total of 15 adverse device effects were reported by 11 of 51 (22%) participants. These included distortions, facial tingling, feedback, incision site soreness or pain, positional vertigo, neck pain, and low performance or reduced performance (that is, reduced speech reception threshold or PTA and functional gain). Three serious adverse device effects were reported in 3 of 51 (6%) participants with two effects related to surgical wound dehiscence (repaired without device removal and complete resolution). Three of 51 participants (5.8%) required device explantation due to development of Meniere disease symptoms, infection, and low implant performance. Five of 51 (9.8%) participants required some type of revision procedure. A limitation of this study includes lack of evaluable data for each of the 49 participants for every annual follow-up visit. In addition, other implanted individuals (n=10) who declined study enrollment were not asked to specify a reason, resulting in a potential bias in the study conclusions if their performance outcomes were unsatisfactory or they experienced adverse effects of implantation. Finally, as there are no validated instruments for hearing aid lifestyle benefits, reported outcomes are subjective.

Barbara (2024) reported on 14 individuals who received the Esteem MEI in one ear and a conventional hearing aid in the other ear. Study participants had moderate to severe symmetric bilateral sensorineural hearing loss. Duration of follow-up and primary efficacy outcomes were not reported. Individuals underwent audiological testing using their Esteem device only, their contralateral conventional hearing aid only and both. For the speech audiometry in quiet test, the mean speech intelligibility with the conventional hearing aid-only was 71% at 69 dB, with the Esteem device-only was 92% at 66 dB and with both devices was 94% at 61 dB. For the speech audiometry in noise test, the mean speech intelligibility, with the conventional hearing aid-only was 56% at 69 dB, with the Esteem device-only was 79% at 66 dB and with both devices was 84% at 61 dB.

Other Considerations

Zwartenkot (2016) reported outcomes from a single-center retrospective cohort study evaluating the long-term medical and technical complications in 94 individuals implanted with either the VSB system, Otologics MET device, or Otologics Carina device. The Otologics devices are not currently FDA approved or cleared for use in the U.S. A total of 128 devices were implanted, including 92 VSB devices, 32 MET devices, and 4 Carina devices. During an average 4.4 years of follow-up (range, 1-15 years), 28 (21.9%) participants were considered lost to follow-up. Reasons for attrition included 7 deaths, 12 explantations, and 6 missed follow-up appointments. During the follow-up period, 36 devices were replaced or explanted (most commonly soon after implantation), with 36% of devices replaced within 18 months of implantation. All four Carina devices had technical difficulties. Twenty (21%) participants had a complication during follow-up, of which 17 were considered serious adverse effects. This was a relatively small study conducted at a single tertiary care center. Both of these factors limit the generalizability of the study’s findings. Additional limitations of this study include a high attrition rate (30%) and lack of a control group.

The AAO-HNS reiterated their position on active middle ear implants in 2025:

The American Academy of Otolaryngology-Head and Neck Surgery considers active middle ear implants as appropriate treatment for adults with moderate to severe hearing loss when performed by a qualified otolaryngologist-head and neck surgeon. Based on available literature demonstrating that clinically selected adults receive substantial benefit, implanting active middle ear implants is accepted medical practice in those who benefit from amplification but are unable to benefit from the amplification provided by conventional hearing aids.

This AAO-HNS position statement cited several small uncontrolled studies that used older versions of the implant technology that were published more than 10 years ago (Boeheim, 2010; Butler, 2013; Wagner, 2010). The design of these studies does not support conclusions regarding the net health benefits of currently available devices. A disclaimer in the position statement states that “In no sense do [AAO-HNS position statements] represent a standard of care.”

None of the devices have been FDA approved for conductive or mixed hearing loss.

Hearing loss is described as conductive, sensorineural or mixed, and can be unilateral or bilateral. Sensorineural or "nerve" hearing loss involves damage to the inner ear or the eighth cranial nerve. It can be caused by aging, prenatal or birth-related problems, viral or bacterial infections, heredity, trauma, exposure to loud noises, the use of certain drugs, fluid buildup in the middle ear, or a benign tumor in the inner ear (acoustic neuroma). Since this type of hearing loss can affect selective portions of a person's range of hearing, the degree of hearing loss and the specific pitches affected will vary from person to person. Even in instances where the pattern of the loss is the same, the degree of sound clarity may vary from person to person or may differ between ears in an individual. As a result, individuals suffering from sensorineural hearing loss often require hearing aids tailored to the specific sensitivity and pattern of their hearing loss. Normal speech and conversation occur at 40-60 dB within a frequency range of 500-3000 Hz. Degree of hearing loss refers to the severity of the loss. Specific numbers are representative of the person’s thresholds, or the softest intensity at which sound is perceived. Clark (1981) reported on one of the more commonly used classification systems for designating the degree of hearing loss based on PTA detection thresholds as mild (20 to 40 dB), moderate (40 to 60 dB), severe (60 to 80 dB), and profound (≥ 80 dB).

Sound amplification through the use of an air-conduction (AC) hearing aid can provide benefit to individuals with sensorineural, conductive, or mixed hearing loss. Contralateral routing of signal (CROS) is a system in which a microphone on the affected side transmits a signal to an air-conduction hearing aid on the normal or less affected side. The most common type of hearing aid for moderate to severe sensorineural hearing loss is an externally worn acoustic hearing aid, which is placed into the external ear canal and functions to amplify sound. These hearing aids may not be satisfactory to some users, either due to issues related to anatomic fit, sound quality, or personal preference.

Implantable Middle Ear Hearing Aids

Externally worn acoustic hearing aids are widely accepted for use by individuals with moderate to severe sensorineural hearing loss. Implantable middle ear hearing aids can be either semi-implantable (partially) or fully implantable (totally) and have been proposed as an alternative to an externally worn acoustic hearing aid for an individual with moderate to severe sensorineural hearing loss. The devices differ in the use of either a piezoelectric transducer (fully implantable) directly coupled to the ossicular chain, or an electromagnetic-based vibration transducer (semi-implantable) placed in approximation to the ossicular chain. There is a fundamental difference as to how sound is amplified and transmitted (delivered) to the inner ear between a conventional acoustic hearing aid and middle ear hearing aids. An acoustic hearing aid uses air pressure to transport sound to the middle ear while a semi-implantable middle ear hearing aid uses periodic attraction and repulsion of two magnetic fields, one from an electromagnet and the other from a static magnet. Fully implantable middle ear hearing aids, in contrast, function by passing an electric current through a piezo-ceramic crystal and driver that uses the natural ear as a microphone.

Semi-Implantable Middle Ear Hearing Aids

The VSB implant consists of three components: a magnetic component that is surgically implanted subcutaneously behind the ear and onto the ossicles of the middle ear (called the vibrating ossicular prosthesis [VORP]), a receiver, and an externally worn audio/sound processor. The processor is worn externally on the scalp over the receiver unit, held in place by a magnet. The VSB implant receives sound from a microphone, amplifies and processes it according to frequency shaping, and then delivers directly an electrical signal to an electromagnetic coil in the ear canal. This coil produces an electromagnetic field within the middle ear space which stimulates a magnet surgically attached under local anesthesia to the ossicular chain (stapes), causing vibrations of the bones of the middle ear similar to normal hearing.

The Maxum System is placed in the  ear canal while the processor rests over the external ear. The sound processor receives and amplifies the sound vibrations and transforms the sound pressure into electrical signals that are received by the receiver unit, which then transduces the electrical signals into electromagnetic energy. This electromagnetic energy creates an alternating electromagnetic field with the magnetic component (floating mass transducer) implanted on the ossicles of the middle ear. The electromagnetic field results in attractive and repulsive forces on the magnetic implant, causing vibration of the bones of the middle ear, similar to normal hearing.

Fully Implantable Middle Ear Hearing Aids (also known as Active Middle Ear Implants)

The Esteem MEI is a fully implantable middle ear hearing system that uses piezoelectric transducers along with the natural ear/eardrum as the microphone. According to the FDA’s Summary of Safety and Effectiveness Data, the hearing aid consists of three implantable components: a sound processor implanted in the temporal bone behind the outer ear; a sensor; and a driver that is implanted in the middle ear. The piezoelectric sensor tip is attached to the incus bone and senses vibrations from the tympanic membrane and malleus/incus, converting these mechanical vibrations into electrical signals that are sent to the sound processor. The sound processor, which is implanted in the temporal bone and connected to the sensor and driver via leads, receives the electrical signal from the sensor, amplifies and filters the signal to compensate for the person’s hearing loss profile; the enhanced signal is then sent to the driver. Finally, the piezoelectric driver tip attached to the stapes/incus bone converts the enhanced electrical signal received from the sound processor back to vibrations which are transferred to the stapes and delivered as sound waves to the cochlea; the cochlea converts the waves to nerve impulses and transmits them to the brain where they are interpreted as sound. In addition to the intended use by adults with stable moderate to severe bilateral sensorineural hearing loss (defined by PTA), the manufacturer states the Esteem MEI is indicated for persons with an unaided speech discrimination test score ≥ 40%, normally functioning eustachian tube, normal middle ear anatomy, normal tympanic membrane, and adequate space for the implant. The person should also have a minimum of 30 days of experience with appropriately fitted hearing aids.

The Carina^® is a fully implantable middle ear hearing device developed from earlier Otologics systems and designed to function without external components. Although it received CE mark approval in Europe, it was never approved by the FDA, largely due to limited clinical evidence, device reliability concerns, and insufficient data demonstrating consistent safety and effectiveness. Commercial availability has since declined, and the device is no longer widely marketed or in active use.

Abbreviated Profile of Hearing Aid Benefit (APHAB): A questionnaire designed to quantify daily activities related to hearing loss by assessing the reduction of disability with a hearing aid.

Air-conduction hearing aid (ACHA): A conventional hearing aid for hearing loss that cannot be medically or surgically corrected.

Asymmetric hearing loss (AHL): A condition in which hearing in the better ear is not normal, but can be restored using a conventional hearing aid (pure-tone average [PTA] between 30 dB HL and 55-60 dB HL).

Conductive hearing loss: Occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the small bones (ossicles) of the middle ear; this disorder involves a reduction in sound level or the ability to hear faint sounds.

Congenital aural atresia (CAA): A rare spectrum of congenital deformities present at birth that involves some degree of failure of the development of the external auditory canal; it is commonly accompanied by abnormalities of both the middle ear bones in various degrees, as well as the external ear, including microtia (small ear) or incomplete development of the auricle (the outer projecting portion of the ear).

Decibel (dB): A unit for expressing the loudness of sound. The intensity relates to how loud or soft a sound is. Sound scales are based on either sound pressure level (dB SPL) or hearing level (dB HL).

Decibels hearing level (dB HL): 0 dB HL is the softest sound that can be heard by the average person with normal hearing. It is not the absence of sound, as persons with better than average hearing will have thresholds lower than 0 dB HL (for example, 10 dB HL).

Degree of hearing loss: According to the American Speech-Language-Hearing Association (ASHA, 2018) (Clark, 1981), the degree of hearing loss refers to the severity of an individual’s hearing loss range in decibels (dB):

Classification of Hearing Loss     Hearing Threshold
Normal hearing                            0 to 20 dB
Mild                                              21 to 40 dB hearing loss
Moderate                                     41 to 55 dB hearing loss
Moderately-severe                      56 to 70 dB hearing loss
Severe                                        71 to 90 dB hearing loss
Profound                                     91 dB or more hearing loss

Hertz (Hz): A unit of frequency equivalent to 1 cycle per second. Frequency of pitch is measured in Hz. Frequencies of 250-8000 Hz are typically used in audiometric testing because this range represents most of the speech spectrum.

Mixed hearing loss: Hearing loss that is both conductive and sensorineural, occurring in one or both ears. This term refers to a condition where conductive hearing loss coexists with sensorineural hearing loss.

Otitis externa: Inflammation or infection of the ear canal.

Piezoelectric: The production of an electric potential when stress is applied.

Pure tone threshold audiometry: The measurement of an individual's hearing sensitivity for calibrated pure tones; includes manual air-conduction measurements at 250, 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz (125 Hz under some circumstances) plus bone-conduction measurements at intervals from 250 Hz to 4000 Hz and at 3000 Hz as needed (ASHA, 2005).

Pure-tone average (PTA): The average of hearing sensitivity (that is, the minimum volume that the person hears) calculated at multiple frequencies (perceived by pitch), typically within the range of 0.25 to 8 kHz (kilohertz).

Pure tone thresholds (PTTs): The faintest tones or softest sound (lowest intensity) a person can hear at least 50% of the time; PTT is measured in dB.

Sensorineural hearing loss (SNHL): A permanent hearing loss related to the sensory or neural structures responsible for hearing that involves a reduction in sound level or ability to hear faint sounds; this disorder affects speech understanding or the ability to hear clearly; the involved structures include, but are not limited to, the cochlea and the acoustic nerve.

Single-sided deafness (SSD): Significant or total hearing loss in one ear; this disorder is sometimes referred to as unilateral sensorineural hearing loss. SSD is defined as a unilateral severe-to-profound deafness (PTA ≥ 70 dB HL), with a contralateral ear that has better, normal or near-normal hearing (PTA ≤ 30 dB HL). SSD may be a result of a congenital unilateral hearing loss, a sudden sensorineural hearing loss, significant head trauma affecting the ear(s), and surgery to treat acoustic neuroma or other tumors of the eighth cranial nerve.

Speech reception threshold: The intensity at which speech is recognized as meaningful symbols; in speech audiometry, it is the dB level at which 50% of spondee words (a bisyllabic word with equivalent stress on each syllable) can be repeated correctly by the individual.

Temporal bone: A bone located on the side of the head that is part of the skull.

Tympanic membrane: The membrane in the ear that vibrates to sound; referred to as the eardrum.

Unilateral hearing loss (UHL): Is generally defined as a condition in which an individual has non-functioning hearing in one ear, receives little or no clinical benefit from amplification in that ear, and has normal or near normal audiometric function in the contralateral ear. UHL includes single-sided deafness (SSD) and asymmetric hearing loss (AHL).

The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services are Investigational and Not Medically Necessary:
For the following procedure codes or when the code describes a procedure or device indicated in the Position Statement section as investigational and not medically necessary.

Peer Reviewed Publications:

1. Barbara M, Biagini M, Monini S. The totally implantable middle ear device 'Esteem' for rehabilitation of severe sensorineural hearing loss. Acta Otolaryngol. 2011; 131(4):399-404.
2. Barbara M, Filippi C, Tarentini S, et al. Esteem® active middle ear implant versus conventional hearing aids: long-term performance. Audiol Neurootol. 2024; 14:1-8.
3. Barbara M, Manni V, Monini S. Totally implantable middle ear device for rehabilitation of sensorineural hearing loss: preliminary experience with the Esteem, Envoy. Acta Otolaryngol. 2009; 129(4):429-432.
4. Barbara M, Volpini L, Monini S. Delayed facial nerve palsy after surgery for the Esteem^® fully implantable middle ear hearing device. Acta Otolaryngol. 2014; 134(4):429-432.
5. Bernardeschi D, Hoffman C, Benchaa T, et al. Functional results of Vibrant Soundbridge middle ear implants in conductive and mixed hearing losses. Audiol Neurootol. 2011; 16(6):381-387.
6. Boeheim K, Pok SM, Schloegel M, Filzmoser P. Active middle ear implant compared with open‐fit hearing aid in sloping high‐frequency sensorineural hearing loss. Otol Neurotol. 2010; 31(3):424‐429.
7. Butler CL, Thavaneswaran P, Lee IH. Efficacy of the active middle‐ear implant in patients with sensorineural hearing loss. J Laryngol Otol. 2013; 127(Suppl 2):S8‐S16.
8. Catisquini EAT, Teixeira MM, Zampronio CDP, et al. Effect of active middle ear implant on auditory speech perception in individuals with ear malformation. Codas. 2025; 37(3):e20240032.
9. Chen DA, Backous DD, Arriaga MA, et al. Phase 1 clinical trial results of the Envoy System: a totally implantable middle ear device for sensorineural hearing loss. Otolaryngol Head Neck Surg. 2004; 131(6):904-916.
10. Clark JG. Uses and abuses of hearing loss classification. ASHA. 1981; 23(7):493-500.
11. Colletti L, Carner M, Mandala M, et al. The floating mass transducer for external auditory canal and middle ear malformations. Otol Neurotol. 2011; 32(1):108-115.
12. Colletti L, Mandala M, Colletti V. Long-term outcome of round window Vibrant SoundBridge implantation in extensive ossicular chain defects. Otolaryngol Head Neck Surg. 2013; 149(1):134-141.
13. Colletti V, Soli SD, Carner M, Colletti L. Treatment of mixed hearing losses via implantation of a vibratory transducer on the round window. Int J Audiol. 2006; 45(10):600-608.
14. Ernst A, Todt I, Wagner J. Safety and effectiveness of the Vibrant Soundbridge in treating conductive and mixed hearing loss: a systematic review. Laryngoscope. 2016; 126(6):1451-1457.
15. Fisch U, Cremers CWR, Lenarz T, et al. Clinical experience with the Vibrant Soundbridge implant device. Otol Neurotol. 2001; 22(6):962-972.
16. Fraysse B, Lavielle JP, Schmerber S, et al. A multicenter study of the Vibrant Soundbridge middle ear implant: early clinical results and experience. Otol Neurotol. 2001; 22(6):952-961.
17. Frenzel H, Hanke F, Beltrame M, et al. Application of the Vibrant Soundbridge to unilateral osseous atresia cases. Laryngoscope. 2009; 119(1):67-74.
18. Gerard JM, Thill MP, Chantrain G, et al. Esteem 2 middle ear implant: our experience. Audiol Neurootol. 2012; 17(4):267-274.
19. Ihler F, Bewarder J, Blum J, et al. Long‐term functional outcome and satisfaction of patients with an active middle ear implant for sensorineural hearing loss compared to a matched population with conventional hearing aids. Eur Arch Otorhinolaryngol. 2014; 271(12):3161‐3169.
20. Iwasaki S, Usami SI, Takahashi H, et al. Round window application of an active middle ear implant: a comparison with hearing aid usage in Japan. Otol Neurotol. 2017; 38(6):e145-e151.
21. Kahue CN, Carlson ML, Daugherty JA, et al. Middle ear implants for rehabilitation of sensorineural hearing loss: a systematic review of FDA approved devices. Otol Neurotol. 2014; 35(7):1228-1237.
22. Kiefer J, Arnold W, Staudenmaier R. Round window stimulation with an implantable hearing aid (Soundbridge) combined with autogenous reconstruction of the auricle - a new approach. ORL J Otorhinolaryngol Relat Spec. 2006; 68(6):378-385.
23. Kraus EM, Shohet JA, Catalano PJ. Envoy Esteem Totally Implantable Hearing System: phase 2 trial, 1-year hearing results. Otolaryngol Head Neck Surg. 2011; 145(1):100-109.
24. Luetje CM, Brackman D, Balkany TJ, et al. Phase III clinical trial results with the Vibrant Soundbridge implantable middle ear hearing device: a prospective controlled multicenter study. Otolaryngol Head Neck Surg. 2002; 126(2):97-107.
25. Mandalà M, Colletti L, Colletti V. Treatment of the atretic ear with round window vibrant soundbridge implantation in infants and children: electrocochleography and audiologic outcomes. Otol Neurotol. 2011; 32(8):1250-1255.
26. Marino R, Linton N, Eikelboom RH, et al. A comparative study of hearing aids and round window application of the vibrant soundbridge (VSB) for patients with mixed or conductive hearing loss. Int J Audiol. 2013; 52(4):209-218.
27. McRackan TR, Clinkscales WB, Ahlstrom JB, et al. Factors associated with benefit of active middle ear implants compared to conventional hearing aids. Laryngoscope. 2018; 128(9):2133-2138.
28. Memari F, Asghari A, Daneshi A, Jalali A. Safety and patient selection of totally implantable hearing aid surgery: Envoy system, Esteem. Eur Arch Otorhinolaryngol. 2011; 268(10):1421-1425.
29. Monini S, Biagini M, Atturo F, Barbara M. Esteem^® middle ear device versus conventional hearing aids for rehabilitation of bilateral sensorineural hearing loss. Eur Arch Otorhinolaryngol. 2013; 270(7):2027-2033.
30. Müller C, Seidler H, Kuch J, et al. Investigations on directional hearing with one-sided fitting of an active middle ear implant or bone conduction hearing implant. Ear Hear. 2025; 46(4):1095-1110.
31. Pulcherio JO, Bittencourt AG, Burke PR, et al. Carina^® and Esteem^®: a systematic review of fully implantable hearing devices. PLoS One. 2014; 9(10):e110636.
32. Sanders ME, Kant E, Smit AL, Stegeman I. The effect of hearing aids on cognitive function: a systematic review. PLoS One. 2021; 16(12):e0261207.
33. Schmuziger N, Schimmann F, Wengen D, et al. Long-term assessment after implantation of the Vibrant Soundbridge device. Otol Neurotol. 2006; 27(2):183-188.
34. Shohet JA, Kraus EM, Catalano PJ. Profound high-frequency sensorineural hearing loss treatment with a totally implantable hearing system. Otol Neurotol. 2011; 32(9):1428-1431.
35. Shohet JA, Kraus EM, Catalano PJ, Toh E. Totally implantable hearing system: five-year hearing results. Laryngoscope. 2018; 128(1):210-216.
36. Snik AF, Cremers CW. Vibrant semi-implantable hearing device with digital sound processing: effective gain and speech perception. Arch Otolaryngol Head Neck Surg. 2001; 127(12):1433-1437.
37. Snik AF, Mylanus EA, Cremers CW, et al. Multicenter audiometric results with the Vibrant Soundbridge, a semi-implantable hearing device for sensorineural hearing impairment. Otolaryngol Clin North Am. 2001; 34(2):373-388.
38. Sterkers O, Boucarra D, Labassi S, et al. A middle ear implant, the Symphonix Vibrant Soundbridge: retrospective study of the first 125 patients implanted in France. Otol Neurotol. 2003; 24(3):27-36.
39. Streitberger C, Perotti M, Beltrame MA, Giarbini N. Vibrant Soundbridge for hearing restoration after chronic ear surgery. Rev Laryngol Otol Rhinol (Bord). 2009; 130(2):83-88.
40. Thomas JP, Voelter C, Neumann K, et al. Vibroplasty in severe congenital or acquired meatal stenosis by coupling an active middle ear implant to the short process of the incus. Otol Neurotol. 2017; 38(7):996-1004.
41. Thurnheer S, Müller T, Linder T, et al. Congenital aural atresia: hearing rehabilitation using active middle-ear implants. J Laryngol Otol. 2023; 137(8):851-865.
42. Tysome JR, Moorthy R, Lee A, et al. Systematic review of middle ear implants: do they improve hearing as much as conventional hearing AIDS? Otol Neurotol. 2010; 31(9):1369-1375.
43. Uziel A, Mondain M, Hagen P, et al. Rehabilitation for high-frequency sensorineural hearing impairment in adults with the Symphonix Vibrant Soundbridge: a comparative study. Otol Neurotol . 2003; 24(5):775-783.
44. Verhaegen VJ, Mylanus EA, Cremers CW, Snik AF. Audiological application criteria for implantable hearing aid devices: a clinical experience at the Nijmegen ORL clinic. Laryngoscope. 2008; 118(9):1645-1649.
45. Wagner F, Todt I, Wagner J, Ernst A. Indications and candidacy for active middle ear implants. Adv Otorhinolaryngol. 2010; 69:20‐26.
46. Zwartenkot JW, Mulder JJ, Snik AF, et al. Active middle ear implantation: long-term medical and technical follow-up, implant survival, and complications. Otol Neurotol. 2016; 37(5):513-519.
47. Zwartenkot JW, Mulder JJ, Snik AF, et al. Vibrant Soundbridge surgery in patients with severe external otitis: complications of a transcanal approach. Otol Neurotol. 2011; 32(3):398-402.

Government Agency, Medical Society, and Other Authoritative Publications:

1. American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS). Active middle ear implants. Implantable hearing devices. Reviewed July 2025. Available at: https://www.entnet.org/resource/position-statement-active-middle-ear-implants/. Accessed on March 30, 2026.
2. U.S. Food and Drug Administration (FDA). Summary of Safety and Effectiveness Data (SSED). Available at:    https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMA/pma.cfm. Accessed on March 30, 2026.
   • Esteem Implantable Hearing System. No. P090018. March 17, 2010.
   • Maxum System (previously Soundtec Direct System). No. P010023. September 7, 2001.
   • Vibrant Soundbridge. No. P990052. August 31, 2000.

1. American Speech-Language-Hearing Association (ASHA). Sensorineural Hearing Loss. Available at:  https://www.asha.org/public/hearing/sensorineural-hearing-loss/. Accessed on March 30, 2026.
2. National Institute on Deafness and Communication Disorders (NIDCD). Hearing aids. Updated October 11, 2022. Available at: https://www.nidcd.nih.gov/health/hearing-aids. Accessed on March 30, 2026.

Carina Fully Implantable MEI
Esteem/Esteem 2 System
Maxum Hearing Implant System
Vibrant Soundbridge System (VSB)

The use of specific product names is illustrative only. It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.

Federal and State law, as well as contract language, including definitions and specific contract provisions/exclusions, take precedence over Medical Policy and must be considered first in determining eligibility for coverage. The member’s contract benefits in effect on the date that services are rendered must be used. Medical Policy, which addresses medical efficacy, should be considered before utilizing medical opinion in adjudication. Medical technology is constantly evolving, and we reserve the right to review and update Medical Policy periodically.

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