A Transcutaneous Active Middle Ear Implant (AMEI) in Children and Adolescents: Long-term, Multicenter Results.

OBJECTIVE: Evaluation of the long-term safety and performance of an active middle ear implant (AMEI) in the treatment of hearing loss in children and adolescents with a primary focus on improvement in speech discrimination. STUDY DESIGN: Prospective, multicentric, single-subject repeated-measures design in which each subject serves as his or her own control. SUBJECTS: Thirty-one pediatric subjects aged 5 to 17 years. INTERVENTION: Implantation of an active middle ear implant. METHODS: Improvement in word recognition scores, speech reception thresholds (SRT) in quiet and noise, in addition to air conduction, bone conduction, and sound field thresholds were evaluated in two age groups. RESULTS: Residual hearing did not change over time and speech intelligibility significantly improved and remained stable after 36 months. Children aged 5 to 9 improved in WRS from 21.92 to 95.38% and in SRT in quiet and in noise respectively from 62.45 dB SPL (sound pressure level) and +1.14 dB SNR to 42.07 dB SPL and -4.45 dB SNR. Adolescents aged 10 to 17 improved in WRS from 12.78 to 84.71% and in SRT in quiet and in noise respectively from 63.96 dB SPL and +3.32 dB SNR to 35.31 dB SPL and -4.55 dB SNR. CONCLUSIONS: The AMEI, under investigation, is a safe treatment for children and adolescents, and significantly improved audiological performance that remains stable on the long-term scale (up to 36 mo postimplantation). In general, all adult-related issues and questions regarding safety and performance can also be applied to the pediatric population, as no apparent specific issues developed.

The Vibrant Soundbridge in Children and Adolescents: Preliminary European Multicenter Results.

OBJECTIVE: Evaluation of safety and efficacy of the Vibrant Soundbridge in the treatment of hearing loss in children and adolescents with primary focus on improvement in speech discrimination. STUDY DESIGN: Prospective, single-subject repeated-measures design in which each subject serves as his/her own control. SETTING: Tertiary referral center. PATIENTS: Nineteen patients aged 5 to 17 years. INTERVENTION: Implantation of an active middle ear implant. MAIN OUTCOME MEASURE: Improvement in word recognition scores, speech reception thresholds, and signal-to-noise ratios (SNRs) were evaluated, in addition to air and bone conduction. Oldenburger Kids Satztest/Oldenburger Satztest sentences and Göttinger/Freiburger monosyllables at 65-dB hearing level were tested in two age groups. RESULTS: Significant speech discrimination improvement was seen in all patients after 6 months. In children 5 to 9 years old, mean monosyllable recognition improved from 28.9% (unaided) to 95.5% (Soundbridge-aided). Aided 50% sentence discrimination at 44.1 dB and SNR of -4.9 dB were measured. In patients 10 to 17 years old, mean word recognition improved from 18.5% to 89.0%, sentence reception threshold improved to 40.2 dB, and SNR to -3.6 dB. Comparison between age groups indicated a slight trend toward quicker adaptation by older subjects. However, after initial adjustment, a higher level of overall benefit was seen at 6 months in younger children. CONCLUSIONS: Currently, the only middle ear implant approved for pediatric patients, the Vibrant Soundbridge, provides an option in cases of congenital aural atresia or disease-induced defects, when surgical intervention and reconstruction is indicated. The 6-month results in this comparatively large study population validated conclusions found in previous trials.

A soft-surgery approach to minimize hearing damage caused by the insertion of a cochlear implant electrode: a guinea pig animal model.

OBJECTIVE: A "soft surgery" technique was applied, using various types of specifically designed dummy electrodes, to mimic cochlear implantation in a guinea pig model, and the degree of hearing-preservation/cochlear damage was assessed. METHODS: Tricolor guinea pigs were divided into 3 groups: group A were implanted with electrodes without any contacts or wires (soft electrode), group B were implanted with electrodes having a metallic wire inside (stiff electrode), and group C underwent a cochleostomy procedure without implantation. Compound action potentials, in the range of 4 to 32 kHz, were used to assess electrophysiologic changes in the hearing function presurgery and postsurgery. Data were collected before surgery, at times t = 0 (immediately after surgery) and at 3, 7, 14, and 30 days. RESULTS: At low frequencies (4-8 kHz), an immediate elevation of hearing threshold was observed in all 3 groups. Higher threshold shifts were more consistent for group B implanted with a stiff electrode, in comparison to the other 2 groups. Animals from group C presented a recovery from hearing loss, starting 3 days after surgery. At high frequencies (16-32 kHz), the elevation of hearing threshold was higher, as compared with the data from the low frequencies. Group C animals presented oscillatory threshold shifts twice, and the recovery to normal threshold values occurred approximately at t = 14 days. CONCLUSION: The data suggest that cochleostomy is minimally harmful to the inner ear and that a soft electrode might better preserve the inner ear integrity than a rigid electrode.

Speech-in-noise and subjective benefit with active middle ear implant omnidirectional and directional microphones: a within-subjects comparison.

OBJECTIVES: 1) To evaluate speech understanding in noise by comparing signal-to-noise ratios for 50% correct word understanding (SNR50) using an omnidirectional and a directional microphone audio processor (AP) in 4 different noise conditions. 2) To compare subjective speech understanding abilities, spatial hearing abilities, and qualitative hearing performance with the 2 processors. STUDY DESIGN: A prospective, single-subjects repeated-measures study design was used to compare speech understanding performance with the 2 APs acutely and after 6 weeks' acclimatization time. SETTING: Tertiary referral center. PATIENTS: Thirteen experienced unilateral German-speaking active middle ear implant users with either mixed or conductive hearing loss were enrolled. INTERVENTION: Directional audio processor. MAIN OUTCOME MEASURES: SNR50 obtained from 4 different noise conditions. RESULTS: SNR50s with the directional AP were lower (better) than with the omnidirectional AP in all noise conditions, although there were no changes in aided PTA thresholds. In acute testing, the mean SNR50 showed a significant directional advantage (DA) for the directional AP in the S0N0 condition of 1.3 dB, in S0NVSB 2.3 dB, in S0Ncont 3.1 dB, and in S0N180 4.5 dB. As expected, the largest DA was found in the S0N180 condition. No DA was expected in the S0N0 condition but was present. After 6 weeks of acclimatization time, no significant change from the acute testing was found, suggesting that patients experienced improved performance with the directional AP, even without acclimatization time. There was no significant change in subjective questionnaire outcomes. CONCLUSION: The directional AP yields immediately improved speech understanding in noise.

International consensus on Vibrant Soundbridge® implantation in children and adolescents.

OBJECTIVE: Active middle ear implants augment hearing in patients with sensorineural, conductive, and mixed hearing losses with great success. However, the application of active middle ear implants has been restricted to compromised ears in adults only. Recently, active middle ear implants have been successfully implanted in patients younger than 18 years of age with all types of hearing losses. The Vibrant Soundbridge (VSB) active middle ear implant has been implanted in more than 60 children and adolescents worldwide by the end of 2008. In October 2008, experts from the field with experience in this population met to discuss VSB implantation in patients below the age of 18. METHODS: A consensus meeting was organized including a presentation session of cases from worldwide centers and a discussion session in which implantation, precautions, and alternative means of hearing augmentation were discussed. At the end of the meeting, a consensus statement was written by the participating experts. The present consensus paper describes the outcomes and medical/surgical complications: the outcomes are favourable in terms of hearing thresholds, speech intelligibility in quiet and in noise, with a low incidence of intra- and postoperative complications. CONCLUSIONS: Taken together, the VSB offers another viable treatment for children and adolescents with compromised hearing. However, other treatment options should also be taken into consideration. The advantages and disadvantages of all possible treatment options should be weighed against each other in the light of each individual case to provide the best solution; counseling should include a.o. surgical issues and MRI compatibility.

Threshold estimation in adult normal- and impaired-hearing subjects using auditory steady-state responses.

BACKGROUND: The aim of the study was to compare the estimation of hearing threshold values by behavioral and electrophysiological (ASSR) methods in subjects with normal hearing and those with sensorineural hearing impairment. MATERIAL/METHODS: Thirty-two subjects (17 male and 15 female) were tested, with a total of 61 ears. Of these, 11 (22 ears) presented normal hearing threshold values (0-19 dBHL) and 21 (39 ears) sensorineural deficits. RESULTS: The data showed that for the normal-hearing subjects the mean +/-SD ASSR threshold was approximately 20+/-11 dB for frequencies of 0.25-1.0 kHz. For higher frequencies the ASSR threshold increased to 40+/-12.5 dB at 8.0 kHz. Regression analysis confirmed that the difference between the ASSR-estimated and behavioral threshold values decreased significantly with the amount of hearing loss. The data showed that for a 10-dB increment of the behavioral threshold, the ASSR threshold increased by 7 dB. The difference of about 27 dB between the two methods observed in normal subjects tends to cancel in hearing loss greater than 95-100 dBHL. CONCLUSIONS: The results of these analyses indicate that the threshold estimates are rather discordant with the behavioral thresholds. in particular it seems that the correction factor applied here does not rely on factors adequately modeled (in terms of instrumentation) to compensate for the effects of hearing loss on ASSR thresholds. The threshold estimation is adequately modeled for high levels of hearing loss, particularly for patients requiring a cochlear implant.

Coupling the Vibrant Soundbridge to cochlea round window: auditory results in patients with mixed hearing loss.

OBJECTIVE: To assess the functional results of the Vibrant Soundbridge (VBS) placed on the round window (RW) in patients with mixed hearing loss. STUDY DESIGN: Retrospective evaluation of functional hearing, with measurements performed 7 to 9 months postoperatively. SETTINGS: Two tertiary referral hospital centers. SUBJECTS: Twelve individuals with mixed severe hearing loss associated with chronic suppurative otitis media and otosclerosis. INTERVENTION: Surgical placement of the VBS mechanical effector in close contact with the RW membrane to directly drive the inner ear fluids. MAIN OUTCOME MEASUREMENT: Functional hearing gain as analyzed via pure-tone audiometry and speech audiometry with VBS off and on in quiet and in noise. RESULTS: We observed a mean gain of 37.5 dB (0.5-4 kHz) with wide individual differences. The overall gain is mainly due to the air-bone gap recovery, whereas a further 12-dB mean improvement of air-conducted threshold is evident at 2 kHz. The speech reception threshold in quiet shows a mean gain of 24 dB, whereas in noise, it requires a signal-to-noise ratio 7 to 13 dB greater than normal-hearing controls. All patients are daily users of their VBS device. CONCLUSION: A middle ear implant capable of directly driving the cochlear fluids seems to be a promising alternative for individuals with a severe to profound mixed hearing loss. However, variability in hearing recovery is great, likely reflecting variability in responsiveness of the cochlea associated with chronic pathologic findings and, possibly, variability in how the VBS effector interfaces with the RW. Modifying the shape of the VBS effector can improve the mechanical coupling to the RW to better exploit the device's amplification power.