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At least 937 records · Page 52Linked to original sources

PubMed1999

Multichannel cochlear implantation in children with large vestibular aqueduct syndrome.

This study examined the postoperative performance of multichannel cochlear implantation in children with severe-to-profound sensorineural hearing loss secondary to large vestibular aqueduct syndrome. Five children between ages 4 and 13 years who had large vestibular aqueducts confirmed by computed tomography scans underwent implantation of a CLARION Multi-Strategy Cochlear Implant between January 1995 and June 1996 at Boys Town National Research Hospital. In addition to preoperative evaluations, they were examined postoperatively with their implants on a battery of open-set speech recognition tests at 3, 6, 12, and 18 months following initial stimulation. Results indicated a noticeable improvement in open-set speech recognition within the first 3 months of implant use compared to preimplant performance with hearing aids. All 5 patients demonstrated substantial benefit from their implants, but there was variation among the children in the rate and amount of improvement in speech recognition skills.

Child↗

PubMed2002

A model of a nucleus 24 cochlear implant fitting protocol based on the electrically evoked whole nerve action potential.

OBJECTIVE: The goal of this study was to model a cochlear implant fitting protocol based on the electrically evoked whole nerve action potential (EAP) measured using the Neural Response Telemetry capabilities of the Nucleus C124M cochlear implant. The model and data were based on the significant correlations found between the EAP threshold and growth function slope and psychophysical threshold and, dynamic range, respectively, in 12 subjects (Franck, Reference Note 3; Franck & Norton, 2001). DESIGN: Using a retrospective split-half study design, these correlations found between psychophysical mapping levels and EAP data from six of the subjects were used in a model to predict psychophysical mapping levels from EAP data of the other six subjects. RESULTS: Predicted psychophysical mapping levels from the model of the EAP-based fitting protocol closely approximated measured cochlear implant fitting psychophysics. CONCLUSIONS: The close approximation of the measured data to the model data indicates the feasibility of the clinical use of an EAP-based cochlear implant fitting protocol. The realization of this model would only require two loudness judgments from the patient, whereas traditional fitting requires 44, and would be fit in a live-voice mode, accounting for across-electrode loudness summation.

Auditory Threshold↗

PubMed2006

Intelligibility of conversational speech produced by children with cochlear implants.

UNLABELLED: The intelligibility of conversational speech produced by six children fitted with cochlear implants before age 3 years was measured longitudinally. Samples were obtained every 3 months during periods of 12-21 months. Intelligibility was measured using both an utterance-by-utterance approach and an approach to the sample as a whole. Statistically significant differences were observed between the two approaches, but the differences were all within the realm of measurement error. Findings indicated that intelligible speech emerges quite rapidly in these children. Conversational intelligibility appears to be superior to that reported in the literature for similar children who use hearing aids but not necessarily as good as in children with normal hearing. Both intelligibility measures were significantly correlated with chronological age, hearing age, and amount of implant use, but were most strongly correlated with chronological age. LEARNING OUTCOMES: The reader will be able to (1) describe some of the issues involved in measuring speech intelligibility in children with cochlear implants and (2) describe the pattern of outcomes for the intelligibility of speech produced by children receiving cochlear implants before age 3 years.

Age Factors↗

PubMed2004

Cochlear implantation in the chronically diseased ear.

PURPOSE OF REVIEW: The presence of chronic ear disease in patients with profound SNHL presents a challenge to the otologic surgeon and was considered, in the past, a contraindication to cochlear implantation. This review discusses options for cochlear implantation in patients with chronically diseased ears. RECENT FINDINGS: Several management options are available for cochlear implantation in patients with chronic suppurative otitis media (CSOM) and severe to profound sensorineural hearing loss (SNHL). CONCLUSION: Cochlear implantation can be safely achieved in patients with CSOM. The approach chosen should be individualized based on clinical findings.

Adolescent↗

PubMed2003

Dynamic range enhancement for cochlear implants.

HYPOTHESIS: The addition of a continuous, unmodulated, high-rate pulse train to sinusoidal stimuli presented by the cochlear implant to implant recipients will result in increases in the psychophysical dynamic range. BACKGROUND: The hearing dynamic range of cochlear implant patients is markedly reduced compared with that of normal-hearing individuals. This has negative implications for both speech perception and sound quality in these patients. It has been suggested that the addition of an unmodulated high-rate pulse train to deafened auditory nerves could create spontaneous-like neural activity, similar to that recorded from normal ears, of which one significant benefit would be an increase in the dynamic range of cochlear implant users. METHODS: Twenty-nine patients who underwent implantation with the Clarion CII device participated in this single-blinded prospective study. The psychophysical dynamic range of 28 of these subjects was measured with sinusoidal stimuli in response to various levels of an additional unmodulated high-rate pulse train. RESULTS: All the tested subjects (n = 28) demonstrated an increase in dynamic range in response to an appropriate level of unmodulated high-rate pulse train. The largest increase in dynamic range for each subject had a mean value of 6.7 dB. CONCLUSION: The addition of an unmodulated high-rate pulse train to the electric signal presented to cochlear implant patients results in significant increases in dynamic range for sinusoidal stimuli.

Acoustic Stimulation↗

PubMed1994

Otopathology in a case of multichannel cochlear implantation.

The histopathology of the temporal bones of a patient who died of unrelated causes 10 weeks following cochlear implantation using a Richards Ineraid device is presented. Deafness was caused by a prolonged course of intravenous gentamycin therapy 5 years prior to implantation. The electrode array of the cochlear implant was left in situ throughout histologic preparation and sectioning. Despite displacement and disruption of supporting structures of the inner ear, particularly in the 6-to-15-mm range as measured from the round window, there was no significant difference in the mean densities of spiral ganglion cells in the implanted and unimplanted sides. This case is presented as evidence that despite significant disruption of supporting elements of the inner ear, which is common during cochlear implantation, there appears to be little effect on the residual spiral ganglion cell count, at least in the short term.

Cell Count↗

PubMed1999

Medical, surgical and audiological complications of the first 100 adult cochlear implant patients in Birmingham.

Of the first 100 patients implanted on the Midland Cochlear Implant Programme the commonest aetiologies of deafness were idiopathic 31 per cent, meningitis 28 per cent and cochlear otosclerosis 16 per cent. The major complication rate was three per cent. The most severe was one individual who post-operatively developed a cerebral infarct and subsequently died. The minor complication rate was 39 per cent, all of which successfully resolved, and included 11 cases of wound infection, nine cases of vertigo, three transient facial palsies and two post-operative bleeds. Older patients and men were most likely to have a post-operative medical complication. Women were more likely to have an abnormal electrode insertion. Meningitis and otosclerosis were the most complicated aetiologies in terms of cochlear ossification and electrode insertion. A non-patient cochlea was associated with fewer active electrodes. In six cases which had been reported pre-operatively as showing patent cochleas, some form of obstructional ossification was encountered. Patients functioning with greater than 15 active electrodes performed better on auditory tests than patients with fewer than 15 active electrodes.

Adult↗

PubMed2004

Cochlear implantation in chronic otitis media.

Patients with chronic otitis media (COM) may have profound sensorineural hearing loss either due to the disease process or secondary to a surgical procedure. Some patients who are candidates for cochlear implantation may have COM coincidentally. The patients in this group need special attention when cochlear implantation is applied. The aim of this study is to evaluate the potential risks and complications in patients with COM. Cochlear implantation was performed in six patients with COM or an infected radical cavity and profound hearing loss. Five of them underwent a two-stage operation, and one had a single-stage operation. Cochlear implantation was performed in all patients without complications. The follow-up period was uneventful. Although such patients have some potential risks, when certain surgical rules are followed very strictly cochlear implantation can be successfully performed in patients with COM.

Adult↗

PubMed1997

Cochlear implantation in a bilateral Mondini dysplasia.

We report the speech perception progress and programming procedures of a case of congenital profound deafness and bilateral Mondini dysplasia implanted with a Nucleus 20 + 2 cochlear implant at the age of six. Unclear relations between electrodes array and cochlear partition made implant programming difficult and non-standard procedures were set. Cochlear implantation may give excellent rehabilitative results also in cochleae with malformation.

Child↗

PubMed1994

Electric auditory brain-stem responses in nucleus multichannel cochlear implant users.

OBJECTIVE: The electrically elicited auditory brain-stem response (EABR) has been proposed as a tool for use in cochlear implant device setting. To systematically examine the relationships of psychophysical perceptions and EABRs, implant users underwent a series of comparative measurements. The characteristics of the EABR were assessed for their predictive value in determining the subjective measures needed to set the implant device. DESIGN: Characteristics of the EABR and various perceptual measures in a group of cochlear implant users served as compared variables in a correlational study. SETTING: The study was carried out in the audiology clinic of a university hospital. The audiology clinic maintained a fully equipped evoked potential laboratory, and was part of an otolaryngology department that supported a cochlear implant program. SUBJECTS: The subjects consisted of 10 consecutively selected postlinguistically deafened adult multichannel cochlear implant users. MAIN OUTCOME MEASURES: Morphology, latency, and amplitude measures of the EABR recordings were compared with behavioral perceptions of threshold, most comfortable and uncomfortable loudness levels. RESULTS: Perceptual measures of threshold were found to be significantly related to the threshold of the EABR across subjects and electrode position. Simple linear regression analysis was used to measure the degree of the relationship. An r value of 0.89 attests to a significant relationship. The EABR wave latencies and amplitudes were found to have no significant relationship to any of the perceptual measures examined. CONCLUSIONS: Although EABR cannot replace behavioral measurements for device setting, in difficult cases EABR thresholds may be used as a starting point from which to estimate settings for the device.

Adult↗

PubMed2002

Short-term auditory memory in children using cochlear implants and its relevance to receptive language.

The aim of this study was to assess auditory sequential, short-term-memory (SSTM) performance in young children using cochlear implants (CI group) and to examine the relationship of this performance to receptive language performance. Twenty-four children, 5 to 11 years old, using the Nucleus 22-electrode cochlear implant, were tested on a number of auditory and visual tasks of SSTM. The auditory memory tasks were designed to minimize the effect of auditory discrimination ability. Stimuli were chosen that children with cochlear implants could accurately identify with a reaction time similar to that of a control group of children with normal hearing (NH group). All children were also assessed on a receptive language test and on a nonverbal intelligence scale. As expected, children using cochlear implants demonstrated poorer auditory and visual SSTM skills than their hearing peers when the stimuli were verbal or were pictures that could be readily labeled. They did not differ from their peers with normal hearing on tasks where the stimuli were less likely to be verbally encoded. An important finding was that the CI group did not appear to have a sequential memory deficit specific to the auditory modality. The difference scores (auditory minus visual memory performance) for the CI group were not significantly different from those for the NH group. SSTM performance accounted for significant variance in the receptive language performance of the CI group. However, a forward stepwise regression analysis revealed that visual spatial memory (one of the subtests of the nonverbal IQ test) was the main predictor of variance in the language scores of the children using cochlear implants.

Acoustic Stimulation↗

PubMed2005

Audiovisual speech perception in elderly cochlear implant recipients.

OBJECTIVES/HYPOTHESIS: This study examined the speech perception skills of a younger and older group of cochlear implant recipients to determine the benefit that auditory and visual information provides for speech understanding. STUDY DESIGN: Retrospective review. METHODS: Pre- and postimplantation speech perception scores from the Consonant-Nucleus-Consonant (CNC), the Hearing In Noise sentence Test (HINT), and the City University of New York (CUNY) tests were analyzed for 34 postlingually deafened adult cochlear implant recipients. Half were elderly (i.e., >65 y old) and other half were middle aged (i.e., 39-53 y old). The CNC and HINT tests were administered using auditory-only presentation; the CUNY test was administered using auditory-only, vision-only, and audiovisual presentation conditions RESULTS: No differences were observed between the two age groups on the CNC and HINT tests. For a subset of individuals tested with the CUNY sentences, we found that the preimplantation speechreading scores of the younger group correlated negatively with auditory-only postimplant performance. Additionally, older individuals demonstrated a greater reliance on the integration of auditory and visual information to understand sentences than did the younger group CONCLUSIONS: On average, the auditory-only speech perception performance of older cochlear implant recipients was similar to the performance of younger adults. However, variability in speech perception abilities was observed within and between both age groups. Differences in speechreading skills between the younger and older individuals suggest that visual speech information is processed in a different manner for elderly individuals than it is for younger adult cochlear implant recipients.

Adult↗

PubMed2006

AutoNR: an automated system that measures ECAP thresholds with the Nucleus Freedom cochlear implant via machine intelligence.

OBJECTIVE: AutoNRT is an automated system that measures electrically evoked compound action potential (ECAP) thresholds from the auditory nerve with the Nucleus Freedom cochlear implant. ECAP thresholds along the electrode array are useful in objectively fitting cochlear implant systems for individual use. This paper provides the first detailed description of the AutoNRT algorithm and its expert systems, and reports the clinical success of AutoNRT to date. METHODS: AutoNRT determines thresholds by visual detection, using two decision tree expert systems that automatically recognise ECAPs. The expert systems are guided by a dataset of 5393 neural response measurements. The algorithm approaches threshold from lower stimulus levels, ensuring recipient safety during postoperative measurements. Intraoperative measurements use the same algorithm but proceed faster by beginning at stimulus levels much closer to threshold. When searching for ECAPs, AutoNRT uses a highly specific expert system (specificity of 99% during training, 96% during testing; sensitivity of 91% during training, 89% during testing). Once ECAPs are established, AutoNRT uses an unbiased expert system to determine an accurate threshold. Throughout the execution of the algorithm, recording parameters (such as implant amplifier gain) are automatically optimised when needed. RESULTS: In a study that included 29 intraoperative and 29 postoperative subjects (a total of 418 electrodes), AutoNRT determined a threshold in 93% of cases where a human expert also determined a threshold. When compared to the median threshold of multiple human observers on 77 randomly selected electrodes, AutoNRT performed as accurately as the 'average' clinician. CONCLUSIONS: AutoNRT has demonstrated a high success rate and a level of performance that is comparable with human experts. It has been used in many clinics worldwide throughout the clinical trial and commercial launch of Nucleus Custom Sound Suite, significantly streamlining the clinical procedures associated with cochlear implant use.

Algorithms↗

PubMed1998

Preliminary experience with neural response telemetry in the nucleus CI24M cochlear implant.

OBJECTIVE: This study aimed to compare recordings of the electrically evoked whole nerve action potential (EAP) made using the reverse telemetry system of the Nucleus CI24M device with those recorded from individuals who use the Ineraid cochlear implant system. STUDY DESIGN: Data were collected in a prospective fashion from Nucleus CI24M cochlear implant users and compared with retrospective data collected from patients who use the Ineraid device. SETTING: All data were collected at the Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics. PATIENTS: Data are reported from 8 patients who use the Nucleus CI24M cochlear implant and 20 patients who use the Ineraid cochlear implant system. INTERVENTIONS: The interventions described in this study were diagnostic in nature. MAIN OUTCOME MEASURES: EAP growth and refractory recovery data are reported. EAP thresholds recorded from patients who use the Nucleus CI24M device also are compared with behavioral thresholds for the stimulus used to evoke the EAP as well as the stimulation levels needed to program the speech processor. RESULTS: EAP morphology, growth, and refractory recovery functions recorded using the Nucleus CI24M reverse telemetry system compared favorably with similar measures recorded from Ineraid cochlear implant users. CONCLUSIONS: Reasonable EAP responses can be recorded using the Nucleus CI24M device. More data are needed to determine whether the information about neural responsiveness available with this device will be clinically useful.

Cochlear Implantation↗

PubMed2006

Acoustic and perceptual appraisal of speech production in pediatric cochlear implant users.

OBJECTIVE: The purpose of the present study was to examine the relationship between objectively measurable acoustic changes in speech production and subjective speech production accuracy and perceived intelligibility immediately following a disruption in auditory feedback normally provided to subjects from a cochlear implant. METHODS: Six children with profound sensorineural hearing loss participated in the study. Their task was to produce speech samples in two conditions: (1) with auditory feedback from their cochlear implants, and (2) without auditory feedback from their cochlear implants. Samples were subjected to both objective and subjective analyses. Objectively, measures were made of duration, fundamental frequency, and the first and second formants of the vowels. Subjectively, two groups of listeners, one familiar with the speech of children with hearing loss and the other unfamiliar, transcribed the productions and provided ratings of intelligibility. RESULTS: All the children in this study exhibited significant differences from the cochlear implant-on to the cochlear implant-off condition, although these changes were not always in the predicted direction, nor were they always perceptually salient. CONCLUSIONS: Consistent with previous studies, children in this investigation demonstrated variable acoustic voice and speech changes following deactivation of their cochlear implant device. Few of these acoustic changes affected speech intelligibility. The results of this study overall suggest that during the initial years following implantation children who are deaf rely to some extent on the auditory feedback provided by a cochlear implant to control and modify F0, duration, and vowel formant production.

Child↗

PubMed1999

Cochlear implant in patients with residual hearing.

OBJECTIVE: The postoperative speech perception abilities of severely hearing-impaired patients with multi-channel cochlear implant were compared with preoperative speech perception performance with conventional hearing aids. METHODS: Cochlear implantation was performed in six severely to profoundly hearing-impaired patients. They had unaided pure-tone thresholds of 70-100-dB HL and aided thresholds of 35-90-dB HL in the better ear, but were not able to perceive speech sounds well with hearing aids. RESULTS: Postoperatively, all the patients had significantly improved speech perception performance, exceeded the average skills of profoundly deaf cochlear implant users, and were able to communicate without writing. CONCLUSION: These results imply that cochlear implant may be indicated for severely to profoundly deaf subjects, if they receive little or no benefit from conventional hearing aids.

Adult↗

PubMed1992

Electrically evoked auditory brainstem responses in cochlear implant patients.

Electrically evoked auditory brainstem responses (EABR) were recorded in completely deaf patients implanted with Ineraid multichannel cochlear implants. Clear and reproducible EABR were obtained from all patients. Parametric differences with auditory brainstem responses (ABR) were demonstrated and can be explained by the different natures of both types of stimulations (electric versus acoustic). Evidence is given that other well-known properties of auditory evoked responses, like 'binaural interaction' or suppression of responses in a forward masking paradigm, can be observed in EABR of implanted patients.

Acoustic Stimulation↗

PubMed1993

Psychological evaluation of adults in a cochlear implant program.

Relatively few papers have been written about the psychological evaluation of cochlear implant patients, compared to the number of reports on surgical and audiological aspects. Formal and informal psychological assessment are an integral part of the cochlear implant program at Manchester and contribute to team decisions about the suitability of patients for implantation. The psychologist also monitors the subsequent progress of recipients. This paper describes the major reasons for carrying out psychological evaluations of prospective recipients and for monitoring their psychological status. The main assessment techniques used in the Manchester program are outlined. Group findings from the initial assessments of the first 40 cochlear implant patients (including five deaf-blind patients) are also reported.

Adaptation, Psychological↗