RESUMEN
AIMS: Patients with the Pendred syndrome suffer very often from a hearing loss. They may be good candidates for a cochlear implantation, but unfortunately, due to the fluctuating character of the hearing loss, they may escape such indication. In the study, we compared speech production and speech acquisition in 2 groups of implanted patients: those with the Pendred syndrome, and standard non-syndromic patients. METHODS: Ten patients with Pendred syndrome were analyzed for speech perception and production. The control group consisted of 41 non-syndromic implanted patients. All implantees were scored according to speech perception, speech production, and the sum of both. The data were statistically analyzed. RESULTS: No statistical difference was found in language acquisition and production in implantees with Pendred syndrome when compared to non-syndromic patients with cochlear implants. Nor there was any difference in speech production and acquisition between the 2 compared groups regarding surgical age, time elapsed after surgery, or age during the testing. CONCLUSION: In this study evaluating language and speech production and acquisition, patients with Pendred syndrome who underwent cochlear implants show comparable results to their implanted peers with deafness of a different etiology.
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Implantes Cocleares/normas , Bocio Nodular/cirugía , Pérdida Auditiva Sensorineural/cirugía , Percepción del Habla/fisiología , Adolescente , Niño , Preescolar , Femenino , Bocio Nodular/complicaciones , Bocio Nodular/psicología , Pérdida Auditiva/etiología , Pérdida Auditiva/cirugía , Pérdida Auditiva Sensorineural/complicaciones , Pérdida Auditiva Sensorineural/psicología , Humanos , MasculinoRESUMEN
Cochlear implants (CIs) are neuroprostheses that partially restore hearing for people with severe-to-profound hearing loss. While CIs can provide good speech perception in quiet listening situations for many, they fail to do so in environments with interfering sounds for most listeners. Previous research suggests that this is due to detrimental interaction effects between CI electrode channels, limiting their function to convey frequency-specific information, but evidence is still scarce. In this study, an experimental manipulation called spectral blurring was used to increase channel interaction in CI listeners using Advanced Bionics devices with HiFocus 1J and MS electrode arrays to directly investigate its causal effect on speech perception. Instead of using a single electrode per channel as in standard CI processing, spectral blurring used up to 6 electrodes per channel simultaneously to increase the overlap between adjacent frequency channels as would occur in cases with severe channel interaction. Results demonstrated that this manipulation significantly degraded CI speech perception in quiet by 15% and speech reception thresholds in babble noise by 5 dB when all channels were blurred by a factor of 6. Importantly, when channel interaction was increased just on a subset of electrodes, speech scores were mostly unaffected and were only significantly degraded when the 5 most apical channels were blurred. These apical channels convey information up to 1 kHz at the apical end of the electrode array and are typically located at angular insertion depths of about 250 up to 500°. These results confirm and extend earlier findings indicating that CI speech perception may not benefit from deactivating individual channels along the array and that efforts should instead be directed towards reducing channel interaction per se and in particular for the most-apical electrodes. Hereby, causal methods such as spectral blurring could be used in future research to control channel interaction effects within listeners for evaluating compensation strategies.
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Percepción Auditiva/fisiología , Cóclea/patología , Sordera/prevención & control , Percepción del Habla/fisiología , Estimulación Acústica , Anciano , Implantación Coclear/métodos , Implantes Cocleares/normas , Sordera/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , RuidoRESUMEN
OBJECTIVE: Single-sided deafness (SSD) is a condition where an individual has a severe to profound sensorineural hearing loss in one ear and normal hearing on the contralateral side. The use of cochlear implants in individuals with SSD leads to functional improvements in hearing. However, it is relatively unclear how sounds incoming via the cochlear implant (independent of the hearing ear) are processed and interpreted by higher-order processes in the brain. METHODS: Scalp electroencephalography and auditory event-related potentials were recorded monaurally from nine experienced single sided cochlear implant users. Speech-in-noise and localisation tests were used to measure functional changes in hearing. RESULTS: cochlear implant use was associated with improvement in speech-in-noise and localisation tests (compared to cochlear implant off). Significant N2 and P3b effects were observed in both cochlear implant and normal hearing ear conditions, with similar waveform morphology and scalp distribution across conditions. Delayed response times and a reduced N2 (but not P3b) effect was measured in the CI condition. CONCLUSION: The brain is capable of using processes similar to those in normal hearing to discriminate sounds presented to the cochlear implant. There was evidence of processing difficulty in the cochlear implant condition which could be due to the relatively degraded signals produced by the cochlear implant compared to the normal hearing ear. SIGNIFICANCE: Understanding how the brain processes sound provided by a cochlear implant highlights how cortical responses can be used to guide implantation candidacy guidelines and influence rehabilitation recommendations.
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Implantes Cocleares/normas , Pérdida Auditiva Sensorineural/fisiopatología , Localización de Sonidos , Percepción del Habla , Adulto , Anciano , Encéfalo/fisiopatología , Potenciales Evocados Auditivos , Femenino , Lateralidad Funcional , Pérdida Auditiva Sensorineural/rehabilitación , Humanos , Masculino , Persona de Mediana EdadAsunto(s)
Recolección de Datos/normas , Vigilancia de Productos Comercializados/métodos , Prótesis e Implantes/normas , Sistema de Registros/normas , Comités Consultivos , Ensayos Clínicos como Asunto , Implantes Cocleares/efectos adversos , Implantes Cocleares/clasificación , Implantes Cocleares/normas , Recolección de Datos/métodos , Aprobación de Recursos , Diagnóstico , Francia , Humanos , Reembolso de Seguro de Salud , Legislación de Dispositivos Médicos , Selección de Paciente , Prótesis e Implantes/efectos adversos , Prótesis e Implantes/clasificación , Control de Calidad , Calidad de Vida , Medición de Riesgo , Resultado del TratamientoRESUMEN
INTRODUCTION: Using the United States Food and Drug Administration (FDA) as example, we argue that regulatory agencies worldwide should review their guidance on cochlear implants (CIs). METHODS: This is a position paper, thus the methods are strictly argumentation. Here we give the motivation for our recommendation. The FDA's original approval of implantation in prelingually deaf children was granted without full benefit of information on language acquisition, on childcaregiver communication, and on the lived experience of being deaf. The CI clinical trials, accordingly, did not address risks of linguistic deprivation, especially when the caregiver's communication is not fully accessible to the prelingually deaf child. Wide variability in the effectiveness of CIs since initial and updated approval has been indicated but has not led to new guidance. Children need to be exposed frequently and regularly to accessible natural language while their brains are still plastic enough to become fluent in any language. For the youngest infants, who are not yet producing anything that could be called language although they might be producing salient social signals (Goldstein et al. Child Dev 80:636-644, 2009), good comprehension of communication from caregiver to infant is critical to the development of language. Sign languages are accessible natural languages that, because they are visual, allow full immersion for deaf infants, and they supply the necessary support for this comprehension. The main language contributor to health outcomes is this combination of natural visual language and comprehension in communication. Accordingly, in order to prevent possible language deprivation, all prelingually deaf children should be exposed to both sign and spoken languages when their auditory status is detected, with sign language being critical during infancy and early childhood. Additionally, all caregivers should be given support to learn a sign language if it is new to them so that they can comprehend their deaf children's language expressions fully. However, both languages should be made accessible in their own right, not combined in a simultaneous or total communication approach since speaking one language and signing the other at the same time is problematic. RESULTS: Again, because this is a position paper, our results are our recommendations. We call for the FDA (and similar agencies in other countries) to review its approval of cochlear implantation in prelingually deaf children who are within the sensitive period for language acquisition. In the meantime, the FDA should require manufacturers to add a highlighted warning to the effect that results with CI vary widely and CIs should not be relied upon to provide adequate auditory input for complete language development in all deaf children. Recent best information on users' experience with CIs (including abandonment) should be clearly provided so that informed decisions can be made. The FDA should require manufacturers' guidance and information materials to include encouragement to parents of deaf children to offer auditory input of a spoken language and visual input of a sign language and to have their child followed closely from birth by developmental specialists in language and cognition. In this way parents can align with providers to prioritize cognitive development and language access in both audio-vocal and visuo-gestural modalities. DISCUSSION: The arguments and recommendations in this paper are discussed at length as they come up.
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Implantes Cocleares/normas , Salud Global/tendencias , United States Food and Drug Administration/normas , Niño , Preescolar , Implantación Coclear/instrumentación , Implantación Coclear/métodos , Implantación Coclear/tendencias , Implantes Cocleares/tendencias , Aprobación de Recursos , Femenino , Humanos , Lactante , Masculino , Estados Unidos , United States Food and Drug Administration/tendenciasRESUMEN
Background and objectives: The cochlear implant is not only meant to restore auditory function, but it also has a series of benefits on the psychomotor development and on the maturation of central auditory pathways. In this study, with the help of neuropsychological tests and cortical auditory potentials (CAEPs), we intend to identify a series of instruments that allow us to monitor children with a cochlear implant, and later on, to admit them into an individualized rehabilitation program. Materials and methods: This is a longitudinal study containing 17 subjects (6 boys and 11 girls) diagnosed with congenital sensorineural hearing loss. The average age for cochlear implantation in our cohort is 22 months old. Each child was tested before the cochlear implantation, tested again 3 months after the implant, and then 6 months after the implant. To test the general development, we used the Denver Developmental Screening Test (DDST II). CAEPs were recorded to assess the maturation of central auditory pathways. Results: The results showed there was progress in both general development and language development, with a significant statistical difference between the overall DQ (developmental quotient) and language DQ before the cochlear implantation and three and six months later, respectively. Similarly, CAEP measurements revealed a decrease of positive-going component (P1) latency after cochlear implantation. Conclusion: CAEPs and neuropsychological tests prove to be useful instruments for monitoring the progress in patients with cochlear implants during the rehabilitation process.
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Corteza Auditiva/crecimiento & desarrollo , Enfermedades Auditivas Centrales/complicaciones , Implantes Cocleares/normas , Enfermedades Auditivas Centrales/cirugía , Preescolar , Implantación Coclear/métodos , Implantes Cocleares/efectos adversos , Femenino , Crecimiento y Desarrollo , Humanos , Lactante , Estudios Longitudinales , Masculino , Trastornos del Neurodesarrollo/complicaciones , Trastornos del Neurodesarrollo/cirugíaRESUMEN
This opinion statement proposes a set of candidacy criteria for vestibular implantation of adult patients with bilateral vestibulopathy (BVP) in a research setting. The criteria include disabling chronic symptoms like postural imbalance, unsteadiness of gait and/or head movement-induced oscillopsia, combined with objective signs of reduced or absent vestibular function in both ears. These signs include abnormal test results recorded during head impulses (video head impulse test or scleral coil technique), bithermal caloric testing and rotatory chair testing (sinusoidal stimulation of 0.1âHz). Vestibular implant (VI) implantation criteria are not the same as diagnostic criteria for bilateral vestibulopathy. The major difference between VI-implantation criteria and the approved diagnostic criteria for BVP are that all included vestibular tests of semicircular canal function (head impulse test, caloric test, and rotatory chair test) need to show significant impairments of vestibular function in the implantation criteria. For this, a two-step paradigm was developed. First, at least one of the vestibular tests needs to fulfill stringent criteria, close to those for BVP. If this is applicable, then the other vestibular tests have to fulfill a second set of criteria which are less stringent than the original criteria for BVP. If the VI-implantation is intended to excite the utricle and/or saccule (otolith stimulation), responses to cervical and ocular vestibular evoked myogenic potentials must be absent in addition to the above mentioned abnormalities of semicircular canal function. Finally, requirements for safe and potentially effective stimulation should be met, including implanting patients with BVP of peripheral origin only, and assessing possible medical and psychiatric contraindications.
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Vestibulopatía Bilateral/diagnóstico , Vestibulopatía Bilateral/cirugía , Investigación Biomédica/normas , Implantes Cocleares/normas , Sociedades Médicas/normas , Pruebas de Función Vestibular/normas , Vestibulopatía Bilateral/fisiopatología , Investigación Biomédica/métodos , Pruebas Calóricas/métodos , Pruebas Calóricas/normas , Prueba de Impulso Cefálico/métodos , Prueba de Impulso Cefálico/normas , Humanos , Pruebas de Función Vestibular/métodos , Vestíbulo del Laberinto/fisiopatología , Vestíbulo del Laberinto/cirugíaRESUMEN
Abstract Introduction: There is evidence pointing to the importance of the evaluation of musical perception through objective and subjective instruments. In Brazil, there is a shortage of instruments that evaluates musical perception. Objective: To develop an instrument to evaluate the recognition of traditional Brazilian melodies and investigate the performance of children with typical hearing. Methods: The study was carried out after approval of the research ethics committee (1.198.607). The instrument was developed in software format with website access, using the languages PHP 5.5.12, Javascript, Cascade style sheets and "HTML5"; database "MYSQL 5.6.17" on the "Apache 2.4.9" server. Fifteen melodies of Brazilian folk songs were recorded in piano synthesized timbre, with 12 seconds per melody reproduction and four second intervals between them. A total of 155 schooled children, aged eight to 11 years, of both sexes, with typical hearing participated in the study. The test was performed in a silent room with sound stimuli amplified by a sound box at 65 dBNA, positioned at 0 azimuth, and at one meter from the participant, the notebook was used for children to play with on the screen on the title and illustration of the melody they recognized they were listening to. The responses were recorded on their own database. Results: The instrument titled "Evaluation of recognition of traditional melodies in children" can be run on various devices (computers, notebooks, tablets, mobile phones) and operating systems (Windows, Macintosh, Android, Linux). Access: http://192.185.216.17/ivan/home/login.php by login and password. The most easily recognized melody was "Cai, cai balão" (89%) and the least recognized was "Capelinha de melão" (25.2%). The average time to perform the test was 3′15″. Conclusion: The development and application of the software proved effective for the studied population. This instrument may contribute to the improvement of protocols for the evaluation of musical perception in children with hearing aid and/or cochlear implants users.
Resumo Introdução: Há evidências que apontam para a importância da avaliação da percepção musical através de instrumentos objetivos e subjetivos. No Brasil, há escassez de instrumentos que avaliem a percepção musical. Objetivo: Desenvolver um instrumento para avaliar o reconhecimento de melodias tradicionais brasileiras e investigar o desempenho de crianças com audição típica. Método: O estudo foi desenvolvido após aprovação do comitê de ética em pesquisa (1.198.607). O instrumento foi desenvolvido em formato de software com acesso ao site, com as linguagens de programação PHP 5.5.12, Javascript, Cascade Style Sheets e HTML5; banco de dados MYSQL 5.6.17 no servidor Apache 2.4.9. Quinze melodias de canções folclóricas brasileiras foram gravadas com timbre sintetizado em piano, com 12 segundos de reprodução da melodia e quatro segundos de intervalo entre elas. Participaram do estudo 155 crianças, alfabetizadas, entre oito e 11 anos, de ambos os sexos, com audição típica. O teste foi feito em sala silenciosa com estímulo sonoro amplificado por uma caixa sonora a 65 dB NA, posicionada a 0 azimute e a um metro do participante e o notebook foi usado para que as crianças brincassem na tela com o título e a ilustração da melodia que eles reconheceram que ouviam. As respostas foram registradas em seu próprio banco de dados. Resultados: O instrumento intitulado "Avaliação do reconhecimento de melodias tradicionais em crianças" pode ser executado em vários dispositivos (computadores, notebooks, tablets, telefones celulares) e sistemas operacionais (Windows, Macintosh, Android, Linux). Acesse: http://192.185.216.17/ivan/home/login.php através de login e senha. A melodia mais facilmente reconhecida foi "Cai cai balão" (89%) e a menos reconhecida foi "Capelinha de melão" (25,2%). O tempo médio para fazer o teste foi de 3′15″. Conclusão: O desenvolvimento e a aplicação do software se mostraram eficazes para a população estudada. Esse instrumento pode contribuir para o aprimoramento de protocolos de avaliação da percepção musical em crianças usuárias de próteses auditivas e/ou usuárias de implante coclear.
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Humanos , Masculino , Femenino , Preescolar , Niño , Percepción de la Altura Tonal/fisiología , Audífonos/normas , Pruebas Auditivas/normas , Música , Brasil , Implantes Cocleares/normas , Pérdida Auditiva/rehabilitaciónRESUMEN
Cochlear implantation in subjects with single-sided deafness (SSD) offers a unique opportunity to directly compare the percepts evoked by a cochlear implant (CI) with those evoked acoustically. Here, nine SSD-CI users performed a forced-choice task evaluating the similarity of speech processed by their CI with speech processed by several vocoders presented to their healthy ear. In each trial, subjects heard two intervals: their CI followed by a certain vocoder in Interval 1 and their CI followed by a different vocoder in Interval 2. The vocoders differed either (i) in carrier type-(sinusoidal [SINE], bandfiltered noise [NOISE], and pulse-spreading harmonic complex) or (ii) in frequency mismatch between the analysis and synthesis frequency ranges-(no mismatch, and two frequency-mismatched conditions of 2 and 4 equivalent rectangular bandwidths [ERBs]). Subjects had to state in which of the two intervals the CI and vocoder sounds were more similar. Despite a large intersubject variability, the PSHC vocoder was judged significantly more similar to the CI than SINE or NOISE vocoders. Furthermore, the No-mismatch and 2-ERB mismatch vocoders were judged significantly more similar to the CI than the 4-ERB mismatch vocoder. The mismatch data were also interpreted by comparing spiral ganglion characteristic frequencies with electrode contact positions determined from postoperative computed tomography scans. Only one subject demonstrated a pattern of preference consistent with adaptation to the CI sound processor frequency-to-electrode allocation table and two subjects showed possible partial adaptation. Those subjects with adaptation patterns presented overall small and consistent frequency mismatches across their electrode arrays.
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Implantación Coclear/métodos , Implantes Cocleares/normas , Pérdida Auditiva Unilateral/rehabilitación , Adulto , Sordera/rehabilitación , Femenino , Humanos , Masculino , Sonido , Habla , Percepción del Habla/fisiología , Ganglio Espiral de la CócleaRESUMEN
Modeling data suggest that sensitivity to the polarity of an electrical stimulus may reflect the integrity of the peripheral processes of the spiral ganglion neurons. Specifically, better sensitivity to anodic (positive) current than to cathodic (negative) current could indicate peripheral process degeneration or demyelination. The goal of this study was to characterize polarity sensitivity in pediatric and adult cochlear implant listeners (41 ears). Relationships between polarity sensitivity at threshold and (a) polarity sensitivity at suprathreshold levels, (b) age-group, (c) preimplantation duration of deafness, and (d) phoneme perception were determined. Polarity sensitivity at threshold was defined as the difference in single-channel behavioral thresholds measured in response to each of two triphasic pulses, where the central high-amplitude phase was either cathodic or anodic. Lower thresholds in response to anodic than to cathodic pulses may suggest peripheral process degeneration. On the majority of electrodes tested, threshold and suprathreshold sensitivity was lower for anodic than for cathodic stimulation; however, dynamic range was often larger for cathodic than for anodic stimulation. Polarity sensitivity did not differ between child- and adult-implanted listeners. Adults with long preimplantation durations of deafness tended to have better sensitivity to anodic pulses on channels that were estimated to interface poorly with the auditory nerve; this was not observed in the child-implanted group. Across subjects, duration of deafness predicted phoneme perception performance. The results of this study suggest that subject- and electrode-dependent differences in polarity sensitivity may assist in developing customized cochlear implant programming interventions for child- and adult-implanted listeners.
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Percepción Auditiva/fisiología , Implantes Cocleares/normas , Ganglio Espiral de la Cóclea/fisiología , Adulto , Niño , Nervio Coclear/fisiología , Sordera , Estimulación Eléctrica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
This study compared spatial speech-in-noise performance in two cochlear implant (CI) patient groups: bimodal listeners, who use a hearing aid contralaterally to support their impaired acoustic hearing, and listeners with contralateral normal hearing, i.e., who were single-sided deaf before implantation. Using a laboratory setting that controls for head movements and that simulates spatial acoustic scenes, speech reception thresholds were measured for frontal speech-in-stationary noise from the front, the left, or the right side. Spatial release from masking (SRM) was then extracted from speech reception thresholds for monaural and binaural listening. SRM was found to be significantly lower in bimodal CI than in CI single-sided deaf listeners. Within each listener group, the SRM extracted from monaural listening did not differ from the SRM extracted from binaural listening. In contrast, a normal-hearing control group showed a significant improvement in SRM when using two ears in comparison to one. Neither CI group showed a binaural summation effect; that is, their performance was not improved by using two devices instead of the best monaural device in each spatial scenario. The results confirm a "listening with the better ear" strategy in the two CI patient groups, where patients benefited from using two ears/devices instead of one by selectively attending to the better one. Which one is the better ear, however, depends on the spatial scenario and on the individual configuration of hearing loss.
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Implantes Cocleares , Percepción del Habla , Adulto , Anciano , Implantes Cocleares/normas , Sordera , Femenino , Audífonos , Pérdida Auditiva , Pruebas Auditivas , Humanos , Masculino , Persona de Mediana Edad , Ruido , Personas con Deficiencia AuditivaRESUMEN
INTRODUCTION: Surgical treatment of deafness by cochlear implants is used for more than 40 years, and during this period permanently, gradual and significant expansion of indications for this surgery has been observed. MATERIAL AND METHODS: In our Department in the years 1994-2018 1480 cochlear implantations were performed, both in adults (647) and in children (883). In this study current indications and the rules for eligibility of patients based on 25 years of experience are presented. RESULTS: Indications for cochlear implantation in adults are: 1) bilateral postlingual deafness, 2) bilateral sensorineural hearing loss - in pure tone audiometry > 70 dB HL (average 500-4000 Hz) and in speech audiometry in hearing aids understanding < 50% of words for the intensity of the stimulus 65 dB, in the absence of the benefits of hearing aids, 3) bilateral profound hearing loss for high frequency with good hearing for low frequency, in the absence of the benefits of hearing aids, 4) some cases of asymmetric hearing loss with intensive tinnitus in the deaf ear. An indication in children is bilateral sensorineural hearing loss > 80dB HL confirmed by hearing tests, after about 6 months of rehabilitation with the use of hearing aids. DISCUSSION: Although cochlear implantation is used for more than 40 years, the indications for this treatment underlies constant modifications. They concern the age of eligible patients, implantation in patients with partially preserved hearing, as well as treatment for patients with difficult anatomical conditions. In many countries, bilateral implantations are commonly performed, and more and more centers recommend this treatment in the case of unilateral deafness or asymmetric hearing loss, especially with the accompanying tinnitus in the deaf ear.
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Implantación Coclear/normas , Implantes Cocleares/normas , Sordera/cirugía , Percepción del Habla , Adulto , Niño , Femenino , Pérdida Auditiva/cirugía , Humanos , MasculinoRESUMEN
This study investigated the number of channels needed for maximum speech understanding and sound quality in 30 adult cochlear implant (CI) recipients with perimodiolar electrode arrays verified via imaging to be completely within scala tympani (ST). Performance was assessed using a continuous interleaved sampling (CIS) strategy with 4, 8, 10, and 16 channels and n-of-m with 16 maxima. Listeners were administered auditory tasks of speech understanding [monosyllables, sentences (quiet and +5 dB signal-to-noise ratio, SNR), vowels, consonants], spectral modulation detection, as well as subjective estimates of sound quality. Results were as follows: (1) significant performance gains were observed for speech in quiet (monosyllables and sentences) with 16- as compared to 8-channel CIS, (2) 16 channels in a 16-of-m strategy yielded significantly higher outcomes than 16-channel CIS for sentences in noise (percent correct and subjective sound quality) and spectral modulation detection, (3) 16 channels in a 16-of-m strategy yielded significantly higher outcomes as compared to 8- and 10-channel CIS for monosyllables, sentences (quiet and noise), consonants, spectral modulation detection, and subjective sound quality, (4) 16 versus 8 maxima yielded significantly higher speech recognition for monosyllables and sentences in noise using an n-of-m strategy, and (5) the degree of benefit afforded by 16 versus 8 maxima was inversely correlated with mean electrode-to-modiolus distance. These data demonstrate greater channel independence with perimodiolar electrode arrays as compared to previous studies with straight electrodes and warrant further investigation of the minimum number of maxima and number of channels needed for maximum auditory outcomes.
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Implantes Cocleares/normas , Software de Reconocimiento del Habla , Habla , Adulto , Anciano , Anciano de 80 o más Años , Electrodos/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , FonéticaRESUMEN
Hearing impaired persons, and particularly hearing-aid and cochlear implant (CI) users, often have difficulties communicating over the telephone. The intelligibility of classical so-called narrowband telephone speech is considerably lower than the intelligibility of face-to-face speech. This is partly because of the lack of visual cues, limited telephone bandwidth, and background noise. This work proposes to artificially extend the standard bandwidth of telephone speech to improve its intelligibility for CI users. Artificial speech bandwidth extension (ABE) is obtained through a front-end signal processing algorithm that estimates missing speech components in the high-frequency spectrum from learned data. A state-of-the-art ABE approach, which already led to superior speech quality for people with normal hearing, is used for processing telephone speech for CI users. Two different parameterizations are evaluated, one being more aggressive than the other. Nine CI users were tested with and without the proposed ABE algorithm. The experimental evaluation shows a significant improvement in speech intelligibility and speech quality over the phone for both versions of the ABE algorithm. These promising results support the potential of ABE, which could be incorporated into a commercial speech processor or a smartphone-based pre-processor that streams the telephone speech to the CI.
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Implantes Cocleares/normas , Acústica del Lenguaje , Inteligibilidad del Habla , Software de Reconocimiento del Habla/normas , Teléfono , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Adults with bilateral cochlear implants (BiCIs) receive benefits in localizing stationary sounds when listening with two implants compared with one; however, sound localization ability is significantly poorer when compared to normal hearing (NH) listeners. Little is known about localizing sound sources in motion, which occurs in typical everyday listening situations. The authors considered the possibility that sound motion may improve sound localization in BiCI users by providing multiple places of information. Alternatively, the ability to compare multiple spatial locations may be compromised in BiCI users due to degradation of binaural cues, and thus result in poorer performance relative to NH adults. In this study, the authors assessed listeners' abilities to distinguish between sounds that appear to be moving vs stationary, and track the angular range and direction of moving sounds. Stimuli were bandpass-filtered (150-6000 Hz) noise bursts of different durations, panned over an array of loudspeakers. Overall, the results showed that BiCI users were poorer than NH adults in (i) distinguishing between a moving vs stationary sound, (ii) correctly identifying the direction of movement, and (iii) tracking the range of movement. These findings suggest that conventional cochlear implant processors are not able to fully provide the cues necessary for perceiving auditory motion correctly.
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Implantes Cocleares/normas , Pérdida Auditiva/fisiopatología , Localización de Sonidos , Adulto , Anciano , Umbral Auditivo , Estudios de Casos y Controles , Señales (Psicología) , Femenino , Pérdida Auditiva/rehabilitación , Humanos , Masculino , Persona de Mediana Edad , Movimiento (Física)RESUMEN
Preserved low-frequency acoustic hearing in cochlear implant (CI) recipients affords combined electric-acoustic stimulation (EAS) that could improve access to low-frequency acoustic binaural cues and enhance spatial hearing. Such benefits, however, could be undermined by interactions between electrical and acoustical inputs to adjacent (spectral overlap) or distant (binaural interference) cochlear places in EAS. This study simulated EAS in normal-hearing listeners, measuring interaural time difference (ITD) and interaural level difference (ILD) discrimination thresholds for a low-frequency noise (simulated acoustic target) in the presence or absence of a pulsatile high-frequency complex presented monotically or diotically (simulated unilateral or bilateral electric distractor). Unilateral distractors impaired thresholds for both cue types, suggesting influences of both binaural interference (which appeared more consistently for ITD than ILD) and physical spectral overlap (for both cue types). Reducing spectral overlap with an EAS gap between 1 and 3 kHz consistently improved binaural sensitivity. Finally, listeners displayed significantly lower thresholds with simulated bilateral versus unilateral electric stimulation. The combined effects revealed similar or better thresholds in bilateral full spectral overlap than in unilateral EAS gap conditions, suggesting that bilateral implantation with bilateral acoustic hearing preservation could allow for higher tolerance of spectral overlap in CI users and improved binaural sensitivity over unilateral EAS.
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Umbral Auditivo , Implantes Cocleares/normas , Localización de Sonidos , Estimulación Acústica/métodos , Adulto , Señales (Psicología) , Estimulación Eléctrica/métodos , Femenino , Humanos , Masculino , Enmascaramiento PerceptualRESUMEN
The benefits of Cochlear implant (CI) technology depend among other factors on the proximity of the electrode array to the spiral ganglion neurons. Laminin, a component of the extracellular matrix, regulates Schwann cell proliferation and survival as well as reorganization of actin fibers within their cytoskeleton, which is necessary for myelination of peripheral axons. In this study we explore the effectiveness of laminin-coated electrodes in promoting neuritic outgrowth from auditory neurons towards the electrode array and the ability to reduce acoustic and electric auditory brainstem response (i.e. aABR and eABR) thresholds. In vitro: Schwann cells and neurites are attracted towards laminin-coated surfaces with longer neuritic processes in laminin-coated dishes compared to uncoated dishes. In vivo: Animals implanted with laminin-coated electrodes experience significant decreases in eABR and aABR thresholds at selected frequencies compared to the results from the uncoated electrodes group. At 1 month post implantation there were a greater number of spiral ganglion neurons and neuritic processes projecting into the scala tympani of animals implanted with laminin-coated electrodes compared to animals with uncoated electrodes. These data suggest that Schwann cells are attracted towards laminin-coated electrodes and promote neuritic outgrowth/ guidance and promote the survival of spiral ganglion neurons following electrode insertion trauma.
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Implantes Cocleares/normas , Laminina/administración & dosificación , Neuronas/fisiología , Órgano Espiral/fisiología , Animales , Animales Recién Nacidos , Supervivencia Celular/fisiología , Células Cultivadas , Electrodos Implantados/normas , Laminina/química , Masculino , Órgano Espiral/citología , Distribución Aleatoria , Ratas , Ratas Endogámicas BN , Ratas Sprague-DawleyRESUMEN
An interactive method for training speech perception in noise was assessed with adult cochlear implant users. The method employed recordings of connected narratives divided into phrases of 4 to 10 words, presented in babble. After each phrase, the listener identified key words from the phrase from among similar sounding foil words. Nine postlingually deafened adult cochlear implant users carried out 12 hr of training over a 4-week period. Training was carried out at home on tablet computers. The primary outcome measure was sentence recognition in babble. Vowel and consonant identification in speech-shaped noise were also assessed, along with digit span in noise, intended as a measure of some important underlying cognitive abilities. Talkers for speech tests were different from those used in training. To control for procedural learning, the test battery was administered repeatedly prior to training. Performance was assessed immediately after training and again after a further 4 weeks during which no training occurred. Sentence recognition in babble improved significantly after training, with an improvement in speech reception threshold of approximately 2 dB, which was maintained at the 4-week follow-up. There was little evidence of improvement in the other measures. It appears that the method has potential as a clinical intervention. However, the underlying sources of improvement and the extent to which benefits generalize to real-world situations remain to be determined.
Asunto(s)
Implantes Cocleares/normas , Instrucción por Computador , Percepción del Habla/fisiología , Anciano , Percepción Auditiva/fisiología , Implantación Coclear , Femenino , Humanos , Masculino , Persona de Mediana Edad , RuidoRESUMEN
In users of a cochlear implant (CI) together with a contralateral hearing aid (HA), so-called bimodal listeners, differences in processing latencies between digital HA and CI up to 9 ms constantly superimpose interaural time differences. In the present study, the effect of this device delay mismatch on sound localization accuracy was investigated. For this purpose, localization accuracy in the frontal horizontal plane was measured with the original and minimized device delay mismatch. The reduction was achieved by delaying the CI stimulation according to the delay of the individually worn HA. For this, a portable, programmable, battery-powered delay line based on a ring buffer running on a microcontroller was designed and assembled. After an acclimatization period to the delayed CI stimulation of 1 hr, the nine bimodal study participants showed a highly significant improvement in localization accuracy of 11.6% compared with the everyday situation without the delay line ( p < .01). Concluding, delaying CI stimulation to minimize the device delay mismatch seems to be a promising method to increase sound localization accuracy in bimodal listeners.
Asunto(s)
Implantes Cocleares/normas , Audífonos , Localización de Sonidos/fisiología , Adulto , Anciano , Percepción Auditiva , Implantación Coclear/instrumentación , Femenino , Audífonos/normas , Humanos , Masculino , Persona de Mediana Edad , Percepción del HablaRESUMEN
Clinical observations suggest that tinnitus may interfere with programming cochlear implants (CIs), the process of optimizing the transmission of acoustic information to support speech perception with a CI. Despite tinnitus being highly prevalent among CI users, its effects and impact on CI programming are obscure. This study characterized the nature, time-course, and impact of tinnitus effects encountered by audiologists and patients during programming appointments. Semistructured interviews with six CI audiologists were analyzed thematically to identify tinnitus effects on programming and related coping strategies. Cross-sectional surveys with 67 adult CI patients with tinnitus and 20 CI audiologists in the United Kingdom examined the prevalence and time-course of those effects. Programming parameters established at CI activation appointments of 10 patients with tinnitus were compared with those of 10 patients without tinnitus. On average, 80% of audiologists and 45% of patients reported that tinnitus makes measurements of threshold (T) levels more difficult because patients confuse their tinnitus with CI stimulation. Difficulties appeared most common at CI activation appointments, at which T levels were significantly higher in patients with tinnitus. On average, 26% of patients reported being afraid of "loud" CI stimulation worsening tinnitus, affecting measurements of loudest comfortable (C) stimulation levels, and 34% of audiologists reported observing similar effects. Patients and audiologists reported that tinnitus makes programming appointments more difficult and tiresome for patients. The findings suggest that specific programming strategies may be needed during CI programming with tinnitus, but further research is required to assess the potential impact on outcomes including speech perception.