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INTRODUCTION: The aim of this study was to examine how bimodal stimulation affects quality of life (QOL) during the postoperative period following cochlear implantation (CI). These data could potentially provide evidence to encourage more bimodal candidates to continue hearing aid (HA) use after CI. METHODS: In this prospective study, patients completed preoperative and 1-, 3-, and 6-month post-activation QOL surveys on listening effort, speech perception, sound quality/localization, and hearing handicap. Fifteen HA users who were candidates for contralateral CI completed the study (mean age 65.6 years). RESULTS: Patients used both devices at a median rate of 97%, 97%, and 98% of the time at 1, 3, and 6 months, respectively. On average, patients' hearing handicap scores decreased by 16% at 1 month, 36% at 3 months, and 30% at 6 months. Patients' listening effort scores decreased by a mean of 10.8% at 1 month, 12.6% at 3 months, and 18.7% at 6 months. Localization significantly improved by 24.3% at 1 month and remained steady. There was no significant improvement in sound quality scores. CONCLUSION: Bimodal listeners should expect QOL to improve, and listening effort and localization are generally optimized using CI and HA compared to CI alone. Some scores improved at earlier time points than others, suggesting bimodal auditory skills may develop at different rates.
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BACKGROUND: Prior studies have shown an advantage for electro-acoustic stimulation (EAS) in cochlear implant (CI) patients with residual hearing, but the degree of benefit can vary. The objective was to explore which factors relate to performance with and acceptance of EAS for CI users with conventional-length electrodes. METHODS: A retrospective chart review was conducted for adults with an average threshold of 75 dB hearing loss or better across 250 and 500 Hz preoperatively (n = 83). All patients underwent cochlear implantation with a conventional-length electrode. Low-frequency audiometric thresholds were measured at initial activation as well as 3 and 12 months postoperatively to determine who met the criteria for EAS. Speech perception for CNC words and AzBio sentences in quiet and +10 dB SNR noise was evaluated 3 and 12 months after activation. RESULTS: Speech perception in quiet and noise was similar regardless of whether or not the patient was eligible for EAS. Less than half of the patients who met the EAS criteria chose to use it, citing reasons such as physical discomfort or lack of perceived benefit. EAS users performed better on CNC words but not sentence recognition than EAS nonusers. CONCLUSIONS: EAS use is dependent on audiologic and nonaudiologic issues. Hearing preservation is possible with conventional electrodes, but hearing preservation alone does not guarantee superior speech perception.
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Estimulación Acústica/métodos , Implantación Coclear/métodos , Implantes Cocleares , Sordera/rehabilitación , Estimulación Eléctrica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Audiometría , Audiometría de Tonos Puros , Umbral Auditivo , Implantación Coclear/instrumentación , Sordera/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ruido , Aceptación de la Atención de Salud , Satisfacción del Paciente , Estudios Retrospectivos , Percepción del Habla , Adulto JovenRESUMEN
OBJECTIVES: There are many potential advantages to combined electric and acoustic stimulation (EAS) with a cochlear implant (CI), including benefits for hearing in noise, localization, frequency selectivity, and music enjoyment. However, performance on these outcome measures is variable, and the residual acoustic hearing may not be beneficial for all patients. As such, we propose a measure of spectral resolution that might be more predictive of the usefulness of the residual hearing than the audiogram alone. In the following experiments, we measured performance on spectral resolution and speech perception tasks in individuals with normal hearing (NH) using low-pass filters to simulate steeply sloping audiograms of typical EAS candidates and compared it with performance on these tasks for individuals with sensorineural hearing loss with similar audiometric configurations. Because listeners with NH had similar levels of audibility and bandwidth to listeners with hearing loss, differences between the groups could be attributed to distortions due to hearing loss. DESIGN: Listeners with NH (n = 12) and those with hearing loss (n = 23) with steeply sloping audiograms participated in this study. The group with hearing loss consisted of 7 EAS users, 14 hearing aid users, and 3 who did not use amplification in the test ear. Spectral resolution was measured with the spectral-temporal modulated ripple test (SMRT), and speech perception was measured with AzBio sentences in quiet and noise. Listeners with NH listened to stimuli through low-pass filters and at two levels (40 and 60 dBA) to simulate low and high audibility. Listeners with hearing loss listened to SMRT stimuli unaided at their most comfortable listening level and speech stimuli at 60 dBA. RESULTS: Results suggest that performance with SMRT is significantly worse for listeners with hearing loss than for listeners with NH and is not related to audibility. Performance on the speech perception task declined with decreasing frequency information for both listeners with NH and hearing loss. Significant correlations were observed between speech perception, SMRT scores, and mid-frequency audiometric thresholds for listeners with hearing loss. CONCLUSIONS: NH simulations describe a "best case scenario" for hearing loss where audibility is the only deficit. For listeners with hearing loss, the likely broadening of auditory filters, loss of cochlear nonlinearities, and possible cochlear dead regions may have contributed to distorted spectral resolution and thus deviations from the NH simulations. Measures of spectral resolution may capture an aspect of hearing loss not evident from the audiogram and be a useful tool for assessing the contributions of residual hearing post-cochlear implantation.
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Implantación Coclear , Implantes Cocleares , Percepción del Habla , Estimulación Acústica , Acústica , Audición , Pruebas Auditivas , HumanosRESUMEN
OBJECTIVES: The purpose of this study was to obtain an electrophysiological analog of masking release using speech-evoked cortical potentials in steady and modulated maskers and to relate this masking release to behavioral measures for the same stimuli. The hypothesis was that the evoked potentials can be tracked to a lower stimulus level in a modulated masker than in a steady masker and that the magnitude of this electrophysiological masking release is of the same order as that of the behavioral masking release for the same stimuli. DESIGN: Cortical potentials evoked by an 80-ms /ba/ stimulus were measured in two steady maskers (30 and 65 dB SPL), and in a masker that modulated between these two levels at a rate of 25 Hz. In each masker, a level series was undertaken to determine electrophysiological threshold. Behavioral detection thresholds were determined in the same maskers using an adaptive tracking procedure. Masking release was defined as the difference between signal thresholds measured in the steady 65-dB SPL masker and the modulated masker. A total of 23 normal-hearing adults participated. RESULTS: Electrophysiological thresholds were uniformly elevated relative to behavioral thresholds by about 6.5 dB. However, the magnitude of masking release was about 13.5 dB for both measurement domains. CONCLUSIONS: Electrophysiological measures of masking release using speech-evoked cortical auditory evoked potentials correspond closely to behavioral estimates for the same stimuli. This suggests that objective measures based on electrophysiological techniques can be used to reliably gauge aspects of temporal processing ability.
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Potenciales Evocados Auditivos/fisiología , Enmascaramiento Perceptual/fisiología , Detección de Señal Psicológica , Habla , Estimulación Acústica , Femenino , Voluntarios Sanos , Humanos , Masculino , Desempeño Psicomotor , Adulto JovenRESUMEN
To make sense of our ever-changing world, our brains search out patterns. This drive can be so strong that the brain imposes patterns when there are none. The opposite can also occur: The brain can overlook patterns because they do not conform to expectations. In this study, we examined this neural sensitivity to patterns within the auditory brainstem, an evolutionarily ancient part of the brain that can be fine-tuned by experience and is integral to an array of cognitive functions. We have recently shown that this auditory hub is sensitive to patterns embedded within a novel sound stream, and we established a link between neural sensitivity and behavioral indices of learning [Skoe, E., Krizman, J., Spitzer, E., & Kraus, N. The auditory brainstem is a barometer of rapid auditory learning. Neuroscience, 243, 104-114, 2013]. We now ask whether this sensitivity to stimulus statistics is biased by prior experience and the expectations arising from this experience. To address this question, we recorded complex auditory brainstem responses (cABRs) to two patterned sound sequences formed from a set of eight repeating tones. For both patterned sequences, the eight tones were presented such that the transitional probability (TP) between neighboring tones was either 33% (low predictability) or 100% (high predictability). Although both sequences were novel to the healthy young adult listener and had similar TP distributions, one was perceived to be more musical than the other. For the more musical sequence, participants performed above chance when tested on their recognition of the most predictable two-tone combinations within the sequence (TP of 100%); in this case, the cABR differed from a baseline condition where the sound sequence had no predictable structure. In contrast, for the less musical sequence, learning was at chance, suggesting that listeners were "deaf" to the highly predictable repeating two-tone combinations in the sequence. For this condition, the cABR also did not differ from baseline. From this, we posit that the brainstem acts as a Bayesian sound processor, such that it factors in prior knowledge about the environment to index the probability of particular events within ever-changing sensory conditions.
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Percepción Auditiva/fisiología , Tronco Encefálico/fisiología , Aprendizaje por Probabilidad , Estimulación Acústica/métodos , Adolescente , Adulto , Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Femenino , Humanos , Masculino , Música , Patrones de Reconocimiento Fisiológico/fisiología , Probabilidad , Sonido , Adulto JovenRESUMEN
Two forms of brainstem plasticity are known to occur: an immediate stimulus probability-based and learning-dependent plasticity. Whether these kinds of plasticity interact is unknown. We examined this question in a training experiment involving three phases: (1) an initial baseline measurement, (2) a 9-session training paradigm, and (3) a retest measurement. At the outset of the experiment, auditory brainstem responses (ABR) were recorded to two unfamiliar pitch patterns presented in an oddball paradigm. Then half the participants underwent sound-to-meaning training where they learned to match these pitch patterns to novel words, with the remaining participants serving as controls who received no auditory training. Nine days after the baseline measurement, the pitch patterns were re-presented to all participants using the same oddball paradigm. Analysis of the baseline recordings revealed an effect of probability: when a sound was presented infrequently, the pitch contour was represented less accurately in the ABR than when it was presented frequently. After training, pitch tracking was more accurate for infrequent sounds, particularly for the pitch pattern that was encoded more poorly pre-training. However, the control group was stable over the same interval. Our results provide evidence that probability-based and learning-dependent plasticity interact in the brainstem.
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Tronco Encefálico/fisiología , Potenciales Evocados Auditivos , Aprendizaje/fisiología , Plasticidad Neuronal/fisiología , Percepción de la Altura Tonal/fisiología , Percepción del Habla/fisiología , Estimulación Acústica , Adulto , Humanos , Masculino , Adulto JovenRESUMEN
OBJECTIVES: Single-sided deafness (SSD) can have consequences for a child's language, educational, and social development. A cochlear implant (CI) is the only device which can restore true binaural hearing, yet they are only approved for children with (SSD) over the age of five in the United States. Reports on speech perception outcomes for children implanted at a younger age are limited. The present study aims to examine the effects of age at implantation, duration of deafness, hearing loss etiology, and presence of additional disabilities on device usage and speech perception outcomes. METHODS: A retrospective chart review was used to examine demographics and speech perception outcomes for 18 children implanted at age five or younger. RESULTS: Speech perception results were highly variable, with some children deriving significant benefit and others demonstrating no sound awareness through the implant alone. Age at implantation and duration of deafness did not have a clear impact on outcomes. Device usage was low in many children, often those with anatomical abnormalities such as a hypoplastic cochlear nerve. There are challenges to assessing speech perception in young children with SSD, leading to a lack of standardized outcome measures. CONCLUSIONS: Early CI for children with SSD may improve speech perception, but benefit is not guaranteed. Candidacy evaluation should consider both medical and audiological factors, in addition to the degree of family support and realistic expectations. Caution is especially warranted in children with significant anatomical anomalies.
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Implantación Coclear , Implantes Cocleares , Sordera , Pérdida Auditiva Unilateral , Percepción del Habla , Niño , Humanos , Preescolar , Pérdida Auditiva Unilateral/cirugía , Pérdida Auditiva Unilateral/rehabilitación , Estudios Retrospectivos , Percepción del Habla/fisiología , Sordera/cirugía , Sordera/rehabilitación , Resultado del TratamientoRESUMEN
OBJECTIVE: To assess the safety of cochlear implants (CIs) in children under 9 months of age to better understand expected postoperative complication rates, and to provide a preliminary look at efficacy. STUDY DESIGN: Single-center retrospective review. SETTING: Tertiary referral center. PATIENTS: Children 5 to 8 months of age who received a CI between 2011 and 2021. INTERVENTIONS: Therapeutic-CI. MAIN OUTCOME MEASURES: The primary outcome was 6-month postoperative complication rate. Secondary outcomes included length of stay, device explantation/reimplantation, rehabilitation supports, and hearing and language outcomes. Complications of children implanted under than 9 months of age was compared with a cohort of children implanted 9 to 18 months of age between the years 2011 and 2016 using a chi-squared test ( p < 0.05). RESULTS: One hundred six children under 9 months of age were implanted (204 CIs) at a mean age of 6.6 months (range: 5-8). Postoperative complications occurred in 28 patients (26%) and were often minor. There were no mortalities. There was no statistically significant difference in complications, including reimplantation rates, between patients implanted under 9 months of age and those implanted 9 to 18 months of age. Speech discrimination outcomes were excellent, and mean spoken language outcomes were near normative for typically developing children. CONCLUSIONS: Cochlear implantation can be a safe and effective treatment option for children 5 to 8 months of age. Early hearing screening and referral for infants to receive appropriate intervention will continue to play a critical role in optimizing speech and language outcomes.
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Implantación Coclear , Implantes Cocleares , Sordera , Percepción del Habla , Niño , Lactante , Humanos , Implantación Coclear/efectos adversos , Implantes Cocleares/efectos adversos , Audición , Habla , Resultado del Tratamiento , Complicaciones Posoperatorias/cirugía , Sordera/cirugíaRESUMEN
INTRODUCTION: Cochlear implants (CIs) provide access to sound for children and adults who do not receive adequate benefit from hearing aids. Age at implantation is known to affect outcomes across the lifespan. AREAS COVERED: The effects of age on CI outcomes are examined for infants, children, adolescents, and older adults. A variety of outcome measures are considered, including speech perception, language, cognition, and quality of life measures. EXPERT OPINION/COMMENTARY: For those meeting candidacy criteria, CIs are beneficial at any age. In general, younger age is related to greater benefit when considering pre-lingual deafness. Other factors such as additional disabilities, may mitigate this effect. Post-lingually deafened adults demonstrate similar benefit regardless of age, though the oldest individuals (80+) may see smaller degrees of improvement from preoperative scores. Benefit can be measured in many ways, and the areas of greatest benefit may vary based on age: young children appear to see the greatest effects of age at implantation on language measures, whereas scores on cognitive measures appear to be most impacted for the oldest population. Future research should consider implantation at extreme ages (5-9 months or > 90 years), unconventional measures of CI benefit including qualitative assessments, and longitudinal designs.
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Implantación Coclear , Implantes Cocleares , Sordera , Audífonos , Percepción del Habla , Niño , Lactante , Adolescente , Humanos , Preescolar , Anciano , Sordera/psicología , Sordera/cirugía , Calidad de VidaRESUMEN
OBJECTIVES: The purpose of this study was to determine the prevalence of ceiling effects for commonly used speech perception tests in a large population of children who received a cochlear implant (CI) before the age of four. A secondary goal was to determine the demographic factors that were relevant for predicting which children were more likely to reach ceiling level performance. We hypothesize that ceiling effects are highly prevalent for most tests. DESIGN: Retrospective chart review of children receiving a CI between 2002 and 2014. RESULTS: 165 children were included. Median scores were above ceiling levels (≥90% correct) for the majority of speech perception tests and all distributions of scores were highly skewed. Children who were implanted earlier, received two implants, and were oral communicators were more likely to reach ceiling-level performance. Age and years of CI listening experience at time of test were negatively correlated with performance, suggesting a non-random assignment of tests. Many children were re-tested on tests for which they had already scored at ceiling. CONCLUSIONS: Commonly used speech perception tests for children with CIs are prone to ceiling effects and may not accurately reflect how a child performs in everyday listening situations.
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OBJECTIVE: Children with high-frequency severe-to-profound hearing loss and low-frequency residual hearing who do not derive significant benefit from hearing aids are now being considered for cochlear implantation. Previous research shows that hearing preservation is possible and may be desirable for the use of electroacoustic stimulation (EAS) in adults, but this topic remains underexplored in children. The goal of this study was to explore factors relating to hearing preservation, acceptance, and benefits of EAS for children. STUDY DESIGN: Retrospective review. SETTING: Tertiary academic medical center. PATIENTS: Forty children (48 ears) with preoperative low-frequency pure-tone averages of 75 dB HL or less at 250 and 500 Hz (n = 48). INTERVENTION: All patients underwent cochlear implantation with a standard-length electrode. MAIN OUTCOME MEASURE: Low-frequency audiometric thresholds, speech perception, and EAS usage were measured at initial stimulation, and 3 and 12 months postoperatively. Outcomes were compared between children with and without hearing preservation, and between EAS users and nonusers. RESULTS: Hearing was preserved at similar rates as adults but worse for children with an enlarged vestibular aqueduct. Fewer than half of children who qualified to use EAS chose to do so, citing a variety of audiologic and nonaudiologic reasons. No differences were detected in speech perception scores across the groups for words, sentences, or sentences in noise tests. CONCLUSIONS: Neither hearing preservation nor EAS use resulted in superior speech perception in children with preoperative residual hearing; rather, all children performed well after implantation.
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Implantación Coclear , Implantes Cocleares , Pérdida Auditiva Sensorineural , Percepción del Habla , Adulto , Humanos , Niño , Estimulación Acústica/métodos , Resultado del Tratamiento , Umbral Auditivo/fisiología , Pérdida Auditiva Sensorineural/cirugía , Implantación Coclear/métodos , Percepción del Habla/fisiología , Audiometría de Tonos PurosRESUMEN
OBJECTIVE: To investigate a new surgical and signal processing technique that provides apical stimulation of the cochlea using a cochlear implant without extending the length of the electrode array. PATIENTS: Three adult patients who underwent cochlear implantation using this new technique. INTERVENTIONS: The patients received a cochlear implant. The surgery differed from the standard approach in that a ground electrode was placed in the cochlear helicotrema via an apical cochleostomy rather than in its typical location underneath the temporalis muscle. Clinical fitting was modified such that low frequencies were represented using the apically placed electrode as a ground. MAIN OUTCOME MEASURES: Pitch scaling and speech recognition. RESULTS: All surgeries were successful with no complications. Pitch scaling demonstrated that use of the apically placed electrode as a ground lowered the perceived pitch of electric stimulation relative to monopolar stimulation. Speech understanding was improved compared with preoperative scores. CONCLUSIONS: The new surgical approach and clinical fitting are feasible. A lower pitch is perceived when using the apically placed electrode as a ground relative to stimulation using an extracochlear ground (i.e., monopolar mode), suggesting that stimulation can be provided more apically without the use of a longer electrode array. Further work is required to determine potential improvements in outcomes and optimal signal processing for the new approach.
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Implantación Coclear , Implantes Cocleares , Sordera , Adulto , Cóclea/fisiología , Cóclea/cirugía , Implantación Coclear/métodos , Sordera/cirugía , Estimulación Eléctrica , Electrodos , Humanos , Percepción de la Altura TonalRESUMEN
AIM: Untreated hearing loss is risk factor for dementia, depression and falls in the elderly population. The present study evaluated the outcomes of cochlear implantation in adults over age 85, including surgical outcomes, speech perception, and implant use. METHODS: Retrospective chart review of 78 patients implanted at a tertiary academic medical center. Co-morbidities, pre-operative hearing thresholds and speech perception scores at 4 time points (pre-operative, and 3 months, 1, 2, and 3 years post-operatively) were collected from charts. Linear mixed models were used to account for missing data points. RESULTS: Medical comorbidities such as hypertension (56%) and heart disease (53%) were common. Surgical complications were rare (5% or less) and minor. Local anesthesia was used for 71% of study patients implanted in the last three years. Significant improvements were seen for speech perception scores on monosyllabic words (37 percentage points), sentences in quiet (45 percentage points) and sentences in noise (28 percentage points). These improvements remained stable to at least two years post-activation. Seventy-one percent of patients wore their implant full time. CONCLUSION: Cochlear implantation is safe and effective for very elderly adults. The use of local anesthesia may increase adoption of cochlear implantation and thus improve the quality of life for this population.
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Implantación Coclear , Implantes Cocleares , Percepción del Habla , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Calidad de Vida , Estudios RetrospectivosRESUMEN
The auditory system is sensitive to stimulus regularities such as frequently occurring sounds and sound combinations. Evidence of regularity detection can be seen in how neurons across the auditory network, from brainstem to cortex, respond to the statistical properties of the soundscape, and in the rapid learning of recurring patterns in their environment by children and adults. Although rapid auditory learning is presumed to involve functional changes to the auditory network, the chronology and directionality of changes are not well understood. To study the mechanisms by which this learning occurs, auditory brainstem and cortical activity was simultaneously recorded via electroencephalogram (EEG) while young adults listened to novel sound streams containing recurring patterns. Neurophysiological responses were compared between easier and harder learning conditions. Collectively, the behavioral and neurophysiological findings suggest that cortical and subcortical structures each provide distinct contributions to auditory pattern learning, but that cortical sensitivity to stimulus patterns likely precedes subcortical sensitivity.
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Two notes sounded sequentially elicit melodic intervals and contours that form the basis of melody. Many previous studies have characterized pitch perception in cochlear implant (CI) users to be poor which may be due to the limited spectro-temporal resolution and/or spectral warping with electric hearing compared to acoustic hearing (AH). Poor pitch perception in CIs has been shown to distort melodic interval perception. To characterize this interval distortion, we recruited CI users with either normal (single sided deafness, SSD) or limited (bimodal) AH in the non-implanted ear. The contralateral AH allowed for a stable reference with which to compare melodic interval perception in the CI ear, within the same listener. Melodic interval perception was compared across acoustic and electric hearing in 9 CI listeners (4 bimodal and 5 SSD). Participants were asked to rank the size of a probe interval presented to the CI ear to a reference interval presented to the contralateral AH ear using a method of constant stimuli. Ipsilateral interval ranking was also measured within the AH ear to ensure that listeners understood the task and that interval ranking was stable and accurate within AH. Stimuli were delivered to the AH ear via headphones and to the CI ear via direct audio input (DAI) to participants' clinical processors. During testing, a reference and probe interval was presented and participants indicated which was larger. Ten comparisons for each reference-probe combination were presented. Psychometric functions were fit to the data to determine the probe interval size that matched the reference interval. Across all AH reference intervals, the mean matched CI interval was 1.74 times larger than the AH reference. However, there was great inter-subject variability. For some participants, CI interval distortion varied across different reference AH intervals; for others, CI interval distortion was constant. Within the AH ear, ipsilateral interval ranking was accurate, ensuring that participants understood the task. No significant differences in the patterns of results were observed between bimodal and SSD CI users. The present data show that much larger intervals were needed with the CI to match contralateral AH reference intervals. As such, input melodic patterns are likely to be perceived as frequency compressed and/or warped with electric hearing, with less variation among notes in the pattern. The high inter-subject variability in CI interval distortion suggests that CI signal processing should be optimized for individual CI users.
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Implantación Coclear , Implantes Cocleares , Sordera , Percepción del Habla , Acústica , Sordera/diagnóstico , Audición , Humanos , Percepción de la Altura Tonal , Sulfadiazina de PlataRESUMEN
OBJECTIVE: To describe our experience with adults undergoing cochlear implantation (CI) for treatment of single-sided deafness (SSD). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Fifty-three adults with SSD. INTERVENTIONS: Unilateral CI. MAIN OUTCOME MEASURES: Speech perception testing in quiet and noise, tinnitus suppression, and device usage from datalogs. RESULTS: The mean age at CI was 53.2 years (SD 11.9). The mean duration of deafness was 4.0 years (SD 7.8). The most common etiology was idiopathic sudden SNHL (50%). Word recognition improved from 8.7% (SD 15) preoperatively to 61.8% (SD 20) at a mean follow-up of 3.3 years (SD 1.8) (pâ<â0.0001). Adaptive speech recognition testing in the "binaural with CI" condition (speech directed toward the front and noise toward the normal hearing ear) revealed a significant improvement by 2.6-dB SNR compared to the preoperative unaided condition (pâ=â0.0002) and by 3.6-dB SNR compared to when a device to route sound to the contralateral side was used (pâ<â0.0001). Tinnitus suppression was reported to be complete in 23 patients (43%) and improved in 20 patients (38%) while the device was on. The addition of the CI did not lead to a decrement in hearing performance in any spatial configuration. Device usage averaged 8.7 (SD 3.7) hours/day. CONCLUSIONS: Cochlear implantation in adult SSD patients can suppress tinnitus and achieve speech perception outcomes comparable with CI in conventional candidates. Modest improvements in spatial hearing were also observed and primarily attributable to the head shadow effect. Careful patient selection and counseling regarding potential benefits are important to optimize outcomes.
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Implantación Coclear , Implantes Cocleares , Sordera , Pérdida Auditiva Unilateral , Localización de Sonidos , Percepción del Habla , Adulto , Sordera/cirugía , Pérdida Auditiva Unilateral/cirugía , Humanos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Introduction: While cochlear implants (CI) prior to 12 months of age have become common, the prevalence and impact of issues that either arise or were not evident prior to implantation is unknown. Methods: Retrospective chart review of children implanted under 12 months of age with minimum 3 years follow up. The children were divided into three groups: those with no identified additional disabilities, those with no known disabilities at time of implantation but diagnosed with additional disabilities following implantation, and those that had known anticipated additional disabilities at time of implantation. Results: 108 children under the age of 12 months were implanted at our Center between 2000 and 2013 with an average age of 9 months at time of implantation and n = 93 met inclusion criteria. In 79.6% (74/93) of children, there were no additional issues detected. In 11.8% (11/93), additional issues were known at the time of implantation while in 8.6% (8/93) of the children were diagnosed with additional issues that were not evident prior to implantation. The auditory and linguistic benefits vary commensurate with the severity of their disabilities. Those with anticipated issues preoperatively did not perform as well. Conclusions: Children implanted below one year of age but diagnosed with additional disabilities following implantation obtained substantial though varying degrees of benefit. In none of these cases would knowledge of the disability have altered the decision to offer early CI. It is important to address these potential issues when counseling families about outcomes.
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Implantación Coclear/estadística & datos numéricos , Discapacidades del Desarrollo/epidemiología , Pérdida Auditiva Sensorineural/cirugía , Enfermedades no Diagnosticadas/epidemiología , Diagnóstico Tardío , Discapacidades del Desarrollo/complicaciones , Discapacidades del Desarrollo/diagnóstico , Femenino , Pérdida Auditiva Sensorineural/complicaciones , Humanos , Lactante , Masculino , Periodo Posoperatorio , Prevalencia , Estudios Retrospectivos , Resultado del Tratamiento , Enfermedades no Diagnosticadas/complicaciones , Enfermedades no Diagnosticadas/diagnósticoRESUMEN
Although modern cochlear implants (CIs) use cathodic-leading symmetrical biphasic pulses to stimulate the auditory nerve, a growing body of evidence suggests that anodic-leading pulses may be more effective. The positive polarity has been shown to produce larger electrically evoked compound action potential (ECAP) amplitudes, steeper slope of the amplitude growth function, and broader spread of excitation (SOE) patterns. Polarity has also been shown to influence pitch perception. It remains unclear how polarity affects the relation between physiological SOE and psychophysical pitch perception. Using a within-subject design, we examined the correlation between performance on a pitch-ranking task and spatial separation between SOE patterns for anodic and cathodic-leading symmetric biphasic pulses for 14 CI ears. Overall, there was no effect of polarity on either ECAP SOE patterns, pitch ranking performance, or the relation between the two. This result is likely due the use of symmetric biphasic pulses, which may have reduced the size of the effect previously observed for pseudomonophasic pulses. Further research is needed to determine if a pseudomonophasic stimulus might further improve the relation between physiology and pitch perception.
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Implantes Cocleares , Potenciales Evocados Auditivos , Discriminación de la Altura Tonal , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Harmony is an important part of tonal music that conveys context, form and emotion. Two notes sounded simultaneously form a harmonic interval. In normal-hearing (NH) listeners, some harmonic intervals (e.g., minor 2nd, tritone, major 7th) typically sound more dissonant than others (e.g., octave, major 3rd, 4th). Because of the limited spectro-temporal resolution afforded by cochlear implants (CIs), music perception is generally poor. However, CI users may still be sensitive to relative dissonance across intervals. In this study, dissonance ratings for harmonic intervals were measured in 11 unilaterally deaf CI patients, in whom ratings from the CI could be compared to those from the normal ear. METHODS: Stimuli consisted of pairs of equal amplitude MIDI piano tones. Intervals spanned a range of two octaves relative to two root notes (F3 or C4). Dissonance was assessed in terms of subjective pleasantness ratings for intervals presented to the NH ear alone, the CI ear alone, and both ears together (NH + CI). Ratings were collected for both root notes for within- and across-octave intervals (1-12 and 13-24 semitones). Participants rated the pleasantness of each interval by clicking on a line anchored with "least pleasant" and "most pleasant." A follow-up experiment repeated the task with a smaller stimulus set. RESULTS: With NH-only listening, within-octave intervals minor 2nd, major 2nd, and major 7th were rated least pleasant; major 3rd, 5th, and octave were rated most pleasant. Across-octave counterparts were similarly rated. With CI-only listening, ratings were consistently lower and showed a reduced range. Mean ratings were highly correlated between NH-only and CI-only listening (r = 0.845, p < 0.001). Ratings were similar between NH-only and NH + CI listening, with no significant binaural enhancement/interference. The follow-up tests showed that ratings were reliable for the least and most pleasant intervals. DISCUSSION: Although pleasantness ratings were less differentiated for the CI ear than the NH ear, there were similarities between the two listening modes. Given the lack of spectro-temporal detail needed for harmonicity-based distinctions, temporal envelope interactions (within and across channels) associated with a perception of roughness may contribute to dissonance perception for harmonic intervals with CI-only listening.
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Purpose: This experiment sought to determine whether children's increased susceptibility to nonsimultaneous masking, particularly backward masking, is evident for speech stimuli. Method: Five- to 9-year-olds and adults with normal hearing heard nonsense consonant-vowel-consonant targets. In Experiments 1 and 2, those targets were presented between two 250-ms segments of 70-dB-SPL speech-shaped noise, at either -30 dB signal-to-noise ratio (Experiment 1) or at the listener's word recognition threshold (Experiment 2). In Experiment 3, the target was presented in steady speech-shaped noise at listener threshold. For all experiments, percent correct was estimated for initial and final consonants. Results: In the nonsimultaneous noise conditions, child-adult differences were larger for the final consonant than the initial consonant whether listeners were tested at -30 dB signal-to-noise ratio (Experiment 1) or at their individual word recognition threshold (Experiment 2). Children were not particularly susceptible to backward masking relative to adults when tested in a steady masker (Experiment 3). Conclusions: Child-adult differences were greater for backward than forward masking for speech in a nonsimultaneous noise masker, as observed in previous psychophysical studies using tonal stimuli. Children's greater susceptibility to nonsimultaneous masking, and backward masking in particular, could play a role in their limited ability to benefit from masker envelope modulation when recognizing masked speech.