In-vivo characterisation of an implanted microphone and totally implantable active middle ear implant.

OBJECTIVE: To objectively evaluate acoustic sensitivity of the implanted microphone, and maximum stable gain of a totally implantable active middle ear implant. DESIGN: Prospective, single centre evaluation. STUDY SAMPLE: Fourteen adult patients. RESULTS: Microphone sensitivity is approx. 10 dB lower than an externally worn conventional hearing aid, at frequencies up to 4000 Hz, and substantially lower at higher frequencies. The masking level due to microphone noise, which determines the softest test tones that can be detected, is estimated at <20 to <30 dB HL up to 1000 Hz, and <40 dB HL at higher frequencies. Maximum stable effective gain is the maximum amplification achievable without causing feedback whistling. In sensorineural hearing loss (SNHL) cases, it is 30-40 dB at frequencies up to 2000 Hz, allowing to compensate for even the maximum recommended hearing loss (60-70 dB HL). In both SNHL and mixed hearing loss (MHL) cases, maximum stable effective gain is lower (+20 to -30 dB) around 3000-6000 Hz. CONCLUSIONS: Microphone sensitivity is high enough to achieve aided thresholds of 20-40 dB HL. A strong correlation between actuator coupling efficiency and maximum stable effective gain implies that any effort to improve actuator efficiency should also increase the available gain.

Surgical and audiological outcomes of a fully implantable middle ear implant: early results from a retrospective multicentre study.

PURPOSE: This paper reports the surgical and audiological outcomes of a large series of patients who received a fully implantable middle ear implant (MEI): carina (Cochlear, Australia). METHODS: This is a multicentre retrospective study involving three tertiary referral centres. Patient data were collected for the first 42 consecutive patients who were fitted with the MEI between 2014 and 2019 (Sheffield from February 2017 to January 2019; São Paulo from April 2015 to September 2017; Porto from December 2014 to May 2017). The main outcome measures included surgical results, free field speech testing with speech recognition thresholds (SRT) and audiological gain. RESULTS: There was one major complication due to infection resulting in a brain abscess and explantation of the device. Three other patients had minor skin infections; no other complications were reported. Results show a functional gain of 19.5 dB (p < 0.05) with the MEI versus unaided condition. SRT improved from 57.4 dB to 44.6 dB with the MEI (p < 0.05). CONCLUSIONS: This fully implanable active MEI offers a reliable option for patients with moderate-to-severe sensorineural or mixed hearing losses especially for those do not tolerate or cannot use conventional hearing aids. It provides significant improvement in hearing as shown in the audiological outcomes. The surgery is relatively straightforward but there is a steep learning curve. The devices are well tolerated by all patients.

Active Middle Ear Implant Patient Outcomes With Adaptive Feedback Canceller.

OBJECTIVE: Evaluation of the audiological patient performance with an upgrade of the firmware from the fixed feedback canceller (FFC) to the adaptive feedback canceller (AFC) on an active middle ear implant. STUDY DESIGN: Retrospective observational nonrandomized group study. SETTING: Private hospital. PATIENTS/INTERVENTIONS: From March 2018 to September 2019, 15 patients implanted with an active middle ear implant, with 6 or more months of experience with a FFC system, were upgraded to an AFC algorithm. MAIN OUTCOME MEASURES: Functional gain, speech perception in silence and in noise, and sound localization capacities were examined. Feedback reduction was also analyzed. RESULTS: Thirteen patients were analyzed. Pure tone audiometric evaluation with FFC (mean value of 48.02 dB) compared with AFC at 1 (mean value of 49.12 dB) and 6 months (mean value of 42.75 dB) revealed no statistically significant differences (p = 0.889 and p = 0.358 respectively).In speech discrimination in silence, clinically relevant improvements were observed with AFC at 1 and 6 months, with a mean value of 41.5 and 38.3 dB, respectively (p = 0.03 and p = 0.021 correspondingly). In speech discrimination in noisy environments, we observed an improvement of the different conditions tested. No differences were found in localization capacities between FFC and AFC at the two different moments of evaluation. CONCLUSIONS: AFC is more effective than FFC in cancelling feedback and improving sound quality, allowing for better speech understanding in silence and in noise.

Effectiveness of cochlear implants in children: long term results.

OBJECTIVES: This study aimed to evaluate the effectiveness, according to the hearing threshold and language performance, of cochlear implants through a period of 10 or more years of follow-up. METHODS: A retrospective chart review was conducted. 132 patients were selected from the children's population that underwent cochlear implantation at the Department of Otorhinolaryngology, Centro Hospitalar e Universitário de Coimbra, from 1992 to 2001, with a minimum follow-up period of 10 years. A comparison of the pure-tone and speech audiometric thresholds between two periods (T0 and T1) was performed. T0 refers to the initial evaluation, immediately after the rehabilitation programme, within the first year after cochlear implantation. T1 refers to the most recent annual assessment, carried out in 2010 and 2011. Speech understanding was also evaluated through word and sentence recognition tests. RESULTS: No statistically significant differences were found between early and late assessments, in paediatric cochlear implants users, after a 10 years period of cochlear implantation. Both speech and pure-tone audiometry seem to stabilize except for 2000 Hz where the results were even better after 10 years. Factors such as age at time of implantation, duration of deafness, aetiology and exchange of the speech processor do not seem to have a role in auditory performance after a long rehabilitation period. In tests of verbal discrimination rates of words and phrases recognition were of 84.6% and 65.1%, respectively. CONCLUSIONS: Cochlear implant is an effective treatment for severe to profound hearing loss in children, contributing to a hearing performance and an appropriate language acquisition, currently comparable to normal hearing children. These benefits appear to keep stable over the years. No deterioration was identified.

Evaluation protocol for amusia: Portuguese sample.

UNLABELLED: Amusia is a disorder that affects the processing of music. Part of this processing happens in the primary auditory cortex. The study of this condition allows us to evaluate the central auditory pathways. OBJECTIVE: To explore the diagnostic evaluation tests of amusia. METHOD: The authors propose an evaluation protocol for patients with suspected amusia (after brain injury or complaints of poor musical perception), in parallel with the assessment of central auditory processing, already implemented in the department. The Montreal Evaluation of Battery of amusia was the basis for the selection of the tests. From this comprehensive battery of tests we selected some of the musical examples to evaluate different musical aspects, including memory and perception of music, ability concerning musical recognition and discrimination. In terms of memory there is a test for assessing delayed memory, adapted to the Portuguese culture. Prospective study. RESULTS AND CONCLUSIONS: Although still experimental, with the possibility of adjustments in the assessment, we believe that this assessment, combined with the study of central auditory processing, will allow us to understand some central lesions, congenital or acquired hearing perception limitations.

Protocolo de avaliação da amusia: exemplo português / Evaluation protocol for amusia: portuguese sample

A amusia é uma disfunção que compromete o processamento musical. Parte desse processamento é feito a nível do cortéx auditivo primário. O estudo dessa afecção permite-nos avaliar também as vias auditivas centrais. OBJETIVO: Explorar os testes de avaliação diagnóstica da amusia. MÉTODO: Os autores propõem um protocolo de avaliação para doentes com suspeita de amusia (após lesão cerebral ou por queixas de má percepção musical), paralelamente com a avaliação do processamento auditivo central, já implementada no serviço. A base dos testes de avaliação assenta na Montreal Battery of Evaluation of Amusia. Desta ampla bateria de testes, foram selecionados alguns dos exemplos musicais para avaliação de diferentes vertentes da área musical, nomeadamente memória e percepção musical, capacidade de reconhecimento e discriminação musical. Em termos de memória, foi criado um teste de avaliação da memória tardia, adaptado à cultura portuguesa. Estudo prospectivo. RESULTADOS e CONCLUSÕES: Embora ainda em fase experimental e com possibilidades de ajustes na avaliação realizada, considera-se que esta avaliação, aliada ao estudo do processamento auditivo central, permitirá compreender algumas lesões e disfunções centrais, congênitas ou adquiridas, que limitam a percepção auditiva.

Amusia is a disorder that affects the processing of music. Part of this processing happens in the primary auditory cortex. The study of this condition allows us to evaluate the central auditory pathways. OBJECTIVE: To explore the diagnostic evaluation tests of amusia. METHOD: The authors propose an evaluation protocol for patients with suspected amusia (after brain injury or complaints of poor musical perception), in parallel with the assessment of central auditory processing, already implemented in the department. The Montreal Evaluation of Battery of amusia was the basis for the selection of the tests. From this comprehensive battery of tests we selected some of the musical examples to evaluate different musical aspects, including memory and perception of music, ability concerning musical recognition and discrimination. In terms of memory there is a test for assessing delayed memory, adapted to the Portuguese culture. Prospective study. RESULTS AND CONCLUSIONS: Although still experimental, with the possibility of adjustments in the assessment, we believe that this assessment, combined with the study of central auditory processing, will allow us to understand some central lesions, congenital or acquired hearing perception limitations.