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PubMed1990

Comparison of hearing aids and cochlear implants in profoundly and totally deaf persons.

Cochlear implants are increasingly used in the rehabilitation of the profoundly and totally deaf. Usually, insufficient gain of speech discrimination with a powerful conventional hearing aid is considered as a prerequisite for a cochlear prosthesis. With recent improvements of electronic systems, the criterion for this decision may change. To keep pace with the technical progress, a battery of speech sound tests suited for minimal auditory capabilities (MAC-battery) was developed and applied to groups of patients fitted with conventional instruments and with two different types of cochlear implants. Based on the comparison of the MAC-battery results of hearing aid groups, with the average performance of an implanted group, most conventionally fitted regular users of hearing aids should not be considered as candidates for cochlear implantation. The MAC-battery, although not a strictly standardized procedure, is a useful instrument for patient counselling and for the selection of implant candidates.

Adolescent↗

PubMed2005

Quality-of-life benefit from cochlear implantation in the elderly.

OBJECTIVE: To compare the audiologic results of geriatric patients receiving cochlear implants with younger age groups and to evaluate the quality of life after cochlear implantation in the geriatric population by means of validated quality-of-life questionnaires. STUDY DESIGN: Cross-sectional study involving 89 postlingually deafened cochlear implant subjects. SETTING: Tertiary referral center. PATIENTS: A total of 89 postlingually deafened patients were included in the study, among which were 25 patients who were aged 70 years or older. INTERVENTIONS: All patients received a cochlear implant. Subjects were implanted with either the Laura, Nucleus 24, or Med-el Combi 40+ cochlear implant systems implementing the SPEAK, ACE, CIS, or CIS+ coding strategies. MEAN OUTCOME MEASURES: Speech recognition was determined by means of phonetically balanced monosyllabic word lists. The Hearing Handicap Inventory for Adults, the Glasgow Benefit Inventory, and the scale for the prediction of hearing disability in sensorineural hearing loss were used to quantify the quality of life. RESULTS: Mean audiologic performance for the three groups increased significantly after implantation (p < 0.001). Postoperative audiologic performance of the geriatric population led to useful hearing, but these scores were significantly lower than for the younger age groups (p = 0.002). However, the quality-of-life outcomes for the geriatric group were similar to those of the younger age groups (p = 0.411 for the Hearing Handicap Inventory for Adults; p = 0.886 for the Glasgow Benefit Inventory). CONCLUSION: The results of this study prove that cochlear implantation in the elderly provides improvements in quality of life and speech understanding, similar to those for younger adult cochlear implant recipients.

Adolescent↗

PubMed2006

Revision cochlear implantation.

Reoperation on a patient with an indwelling cochlear implant is uncommon. When necessary, surgery is performed for explantation of an existing device with immediate or delayed reimplantation, or for scalp flap revision and receiver-stimulator repositioning in the case of infection or device migration. Rarely, revision surgery is performed to reintroduce intracochlear electrodes that may have partly or entirely extruded from the cochlea or were placed inappropriately. Successful revision cochlear implant surgery requires attention to certain surgical principles. Good outcomes, asa measured by speech perception tests, are common, but are not guaranteed. This article outlines the indications for revision cochlear implant surgery, the recommended surgical principles, and published outcomes from reimplantation.

Cochlear Implantation↗

PubMed2006

Vestibular-evoked myogenic potentials in cochlear implant children.

CONCLUSIONS: Our results suggest that the sacculi of most children with cochlear implants can easily be damaged, as shown by the absence of vestibular-evoked myogenic potentials (VEMPs) in response to click stimuli. Also, in most of the children, the vestibular nerve was seemingly not stimulated by the cochlear implant. These results suggest that electrical stimulation at the C level can stimulate the cochlear nerve; however, this stimulation did not spread to the vestibular nerve in our children. In some children with Mondini dysplasia or vestibulocochlear nerve abnormality, the vestibular nerve was stimulated when the cochlear implant device was on, because of a VEMP response to electrical stimulation. OBJECTIVE: To clarify the diagnostic value of VEMPs in cochlear implant patients. MATERIAL AND METHODS: The click-evoked myogenic potentials of 12 children who underwent cochlear implantation surgery were investigated. The latency and amplitude of the VEMP responses were measured. RESULTS: Before surgery, 6 of the 12 children showed normal VEMPs, 1 showed a decrease in the amplitude of VEMPs and five showed no VEMP response. After surgery, with the cochlear implant device off, 1 child showed a decreased VEMP and 11 showed no VEMPs. With the cochlear implant device on, four children showed VEMPs and eight did not.

Caloric Tests↗

PubMed1993

Surgical pitfalls in cochlear implantation.

Increasing experience with cochlear implantation has led to the identification of potential surgical pitfalls: improper patient selection, poor flap design and handling, facial nerve injury, improper electrode placement, and improper seating of the receiver stimulator. Each of these areas of potential difficulty are reviewed, emphasizing methods of avoidance and management of adverse outcome.

Cochlear Implants↗

PubMed1999

Evaluation of cochlear implanted children's voices.

Cochlear implant (CI) is a good means in developing communication in deaf children. Nevertheless, compared to children with the same age, CI patients' voices are far from being similar. In this work, the voice of CI children has been compared with the voice of corresponding normal children (same age, same sex) included in the main stream. Six girls and two boys participated to the experiment. The phonetic material was a paragraph of the French standard text La bise et le soleil (The North Wind and the Sun). An objective and a subjective analysis of the voice were done and parameters were compared between both groups of people (implantees and control). Studied parameters were voice pitch, intensity, fluency, pauses, articulation and pleasantness in the objective analysis, and voice pitch, formants, and duration for the objective study. It appeared that intensity variations were different between control and implanted subjects. Also voice formants were not situated in the same region regarding the normal ranges, but differences were difficult to assess. Globally, the main change was in the speaking duration. This method is open for further studies and points out some relevant items for an efficient use in rehabilitation sessions.

Adolescent↗

PubMed1992

[Cochlear implantation].

Since the Israeli cochlear implant program was started in June 1989, 74 candidates have been evaluated for implantation. The main causes for hearing loss were meningitis (16 patients), aminoglycoside toxicity (9), congenital (6), viral (e.g. mumps) (6), and middle ear infection. Candidates were rejected mainly due to psychosocial factors (40%) and audiological parameters (30%). 16 postlingual deaf were implanted. In 7 of them (43.7%) the results were excellent, in 4 (25.0%) good, in 3 (18.7%) fair; 1 case is currently in a training program and 1 is a failure. There were 2 major complications: facial nerve palsy which necessitated surgical decompression, and insertion of the electrodes into the hypotympanic air cells, corrected by reoperation.

Cochlear Implants↗

PubMed1988

[Predictability of the result following cochlear implantation].

The results of cochlear implantation of 28 patients were compared with theoretical prognosis based on a mathematical formula, consisting of: speech competence, duration of deafness in the ear to be operated on, speech comprehension for numbers and the threshold for electrical stimulation using a promontorial electrode. Since the evaluation of this formula, 19 further cases have been operated on, confirming the usefulness of this prognostic scheme.

Audiometry, Speech↗

PubMed1992

Case report: top hearing performances of a postlingually deaf cochlear implant user.

On the occasion of the Cochlear Implant Symposium in Geneva in October 1991, top hearing results attained by a young postlingually deaf woman with cochlear implant systems were presented in video recordings. These data are centered on demanding hearing performances in test situations and in a telephone conversation. For various reasons, two reimplantations were necessary in this deaf patient. Initially, she was provided with a single-channel extra-cochlear electrode of the Vienna type, which she found to improve her lipreading substantially, and she attained an unexpectedly good understanding of speech on a purely auditory basis. Today, this postlingually deaf women uses a multichannel intracochlear electrode of the Nucleus type. The excellent results with the first extracochlear system are clearly surpassed with the intracochlear system. Not least because of her above-average speech competence, the cochlear implant user attains a high degree of open speech understanding. Her verbal hearing efficiency is comparable to that of a person with mild to moderately severe hearing loss.

Adolescent↗

PubMed1997

Labeling of musical interval size by cochlear implant patients and normally hearing subjects.

OBJECTIVE: To compare the performance of cochlear implant patients and normal-hearing subjects on a musical interval labeling task, and to determine whether information regarding musical interval size is available to cochlear implant patients under realistic everyday listening conditions. DESIGN: Two Nucleus cochlear implant patients listened to musical intervals that consisted of systematic variations of electric pulse rate on single bipolar intracochlear electrode pairs, whereas normal-hearing listeners were presented with the acoustical analog of these stimuli. Subjects labeled the intonation quality of the stimulus intervals ("flat," "sharp," or "in tune"), relative to their memory for specific intervals abstracted from familiar melodies. The cochlear implant patients, in addition, performed this task with realistic acoustical musical stimuli. RESULTS: The interval labeling behavior of cochlear implant subjects, at low pulse rates, was similar to that of normal-hearing subjects. Furthermore, pitch interval information does not appear to be available to cochlear implant subjects when they are listening to acoustical stimuli via their speech processors. CONCLUSIONS: Temporal information appears to be sufficient for the perception of musical pitch. Encoding strategies that are highly successful in restoring speech understanding do not necessarily provide information regarding melodic pitch interval size.

Auditory Perception↗

PubMed1994

Facial nerve stimulation after successful multichannel cochlear implantation.

Postoperative rehabilitation after cochlear implantation may be difficult and frustrating for both patient and audiologist. The occurrence of facial nerve stimulation with associated twitching and discomfort can interfere with the rehabilitative process and be a cause of great concern to the patient. Such stimulation can occur at the time of initial "tune-up" or can be delayed by months or years. The incidence of postoperative facial nerve stimulation 109 consecutive patients operated by the same surgeon over a period of 7 years is reviewed. Possible causes for immediate and delayed stimulation are discussed, and strategies at surgery are outlined. Rehabilitative techniques for dealing with facial nerve stimulation are reviewed.

Aged↗

PubMed1990

Audio-visual consonant recognition with the 3M/House cochlear implant.

Eight experienced 3M/House cochlear implant users' consonant recognition was evaluated with videotaped vowel-consonant vowel lists presented in auditory implant only (A), visual (V), and auditory-visual (AV) conditions. All subjects' scores were better than chance. Results revealed that the AV scores were significantly better than the V scores, which were better than the A scores. Sequential Information Analysis of the consonant errors revealed that different features were transmitted better in each condition. Sonorant and voicing features were transmitted well for the A condition, but features related to high-frequency and place cues were not. Place features were transmitted best in the V condition, but acoustic features were not. Both place and acoustic features were transmitted in the AV condition, but they were influenced most by visual cues.

Auditory Perception↗

PubMed2006

Pure-tone auditory stream segregation and speech perception in noise in cochlear implant recipients.

This study examined the ability of cochlear implant users and normal-hearing subjects to perform auditory stream segregation of pure tones. An adaptive, rhythmic discrimination task was used to assess stream segregation as a function of frequency separation of the tones. The results for normal-hearing subjects were consistent with previously published observations (L.P.A.S van Noorden, Ph.D. dissertation, Eindhoven University of Technology, Eindhoven, The Netherlands 1975), suggesting that auditory stream segregation increases with increasing frequency separation. For cochlear implant users, there appeared to be a range of pure-tone streaming abilities, with some subjects demonstrating streaming comparable to that of normal-hearing individuals, and others possessing much poorer streaming abilities. The variability in pure-tone streaming of cochlear implant users was correlated with speech perception in both steady-state noise and multi-talker babble. Moderate, statistically significant correlations between streaming and both measures of speech perception in noise were observed, with better stream segregation associated with better understanding of speech in noise. These results suggest that auditory stream segregation is a contributing factor in the ability to understand speech in background noise. The inability of some cochlear implant users to perform stream segregation may therefore contribute to their difficulties in noise backgrounds.

Adult↗

PubMed1998

Intracochlear factors contributing to psychophysical percepts following cochlear implantation.

The performance of cochlear implant patients may be related to intracochlear, histopathological factors. We have performed detailed post-mortem examinations of five human, implanted cochleas and for each electrode correlated the psychophysical threshold, comfortable level and dynamic range with spiral ganglion cell survival, presence of fibrous tissue and/or new bone, and distance between the centers of the electrode bands and Rosenthal's canal. The psychophysical parameters were strongly interrelated. Threshold and comfort levels correlated with the distance between the electrodes and Rosenthal's canal. Threshold levels also correlated with the presence of intracochlear fibrous tissue and new bone, especially with the former. The dynamic range showed a negative correlation with intracochlear pathology, especially with new bone. Comfort levels and dynamic range were related to spiral ganglion cell survival. The distance between the electrodes and the modiolus increased with increasing levels of fibrous tissue and new bone. Spiral ganglion cell survival was decreased with increasing levels of fibrous tissue and new bone.

Adult↗

PubMed1999

Adaptation by normal listeners to upward spectral shifts of speech: implications for cochlear implants.

Multi-channel cochlear implants typically present spectral information to the wrong "place" in the auditory nerve array, because electrodes can only be inserted partway into the cochlea. Although such spectral shifts are known to cause large immediate decrements in performance in simulations, the extent to which listeners can adapt to such shifts has yet to be investigated. Here, the effects of a four-channel implant in normal listeners have been simulated, and performance tested with unshifted spectral information and with the equivalent of a 6.5-mm basalward shift on the basilar membrane (1.3-2.9 octaves, depending on frequency). As expected, the unshifted simulation led to relatively high levels of mean performance (e.g., 64% of words in sentences correctly identified) whereas the shifted simulation led to very poor results (e.g., 1% of words). However, after just nine 20-min sessions of connected discourse tracking with the shifted simulation, performance improved significantly for the identification of intervocalic consonants, medial vowels in monosyllables, and words in sentences (30% of words). Also, listeners were able to track connected discourse of shifted signals without lipreading at rates up to 40 words per minute. Although we do not know if complete adaptation to the shifted signals is possible, it is clear that short-term experiments seriously exaggerate the long-term consequences of such spectral shifts.

Adolescent↗

PubMed2002

Surgery and functional outcomes in deaf children receiving cochlear implants before age 2 years.

OBJECTIVE: To examine the feasibility of cochlear implantation in children younger than 2 years regarding surgery and functional outcomes. DESIGN: Prospective study. SETTING: Tertiary pediatric cochlear implant center. PATIENTS: A consecutive sample of 12 children younger than 2 years at the time of cochlear implantation (8 boys and 4 girls). The cause of hearing loss was meningitis in 6 children and congenital in 6. INTERVENTIONS: Multichannel cochlear implantation using the Nucleus C124M (Cochlear Co, Sydney, Australia) device. Functional outcome was assessed using the Listening Progress Profile and the Categories of Auditory Performance. MAIN OUTCOME MEASURES: Perioperative and postoperative surgical complications and functional outcome. RESULTS: Eight children had a completely patent cochlea. Four children required a 3- to 5-mm drilling to reach the scala tympani because of ossification after meningitis. Full insertion was achieved in 11 patients; the other child received 18 electrodes. One patient had temporary facial nerve weakness; 2 others had wound edema and serous discharge that resolved with conservative management. In the longer term, 1 child experienced a single episode of acute otitis media; another had recurrent episodes of otitis media. Mean Listening Progress Profile scores increased from 1 to 42 and median Categories of Auditory Performance scores increased from 0 to 5 at 2 years postsurgery. Comparison with the scores in the 2- to 5-year group showed no significant differences. No significant tuning difficulties were experienced with all children. CONCLUSIONS: Cochlear implantation is feasible in children younger than 2 years without significant surgical complications or particular tuning difficulties. Functional results 2 years after implantation were as good as or better than those of children who underwent implantation between ages 2 and 5 years.

Cochlea↗

PubMed1999

Correlation between rCBF and speech perception in cochlear implant users.

OBJECTIVE: Although cochlear implants (CIs) have provided the opportunity for bilaterally deaf individuals to recover their hearing abilities, the speech perception performances of the CI users varies considerably. To elucidate the cortical mechanisms of processing speech signals coded by CIs, we evaluated the correlation between the brain activity during speech activation and speech perception in CI users by PET. METHODS: Fourteen postlingually deaf CI users were examined. CI used in the patients was a 22-channel system and its speech-coding strategy was the Nucleus spectral peak (SPEAK) strategy. To evaluate the speech perception performances, we examined vowel perception, consonant perception and speech tracking performances in the Japanese language. Regional cerebral blood flow (rCBF) was measured during no sound stimulation and speech sound stimulation. PET data of the silent condition was subtracted from that of speech stimulation to determine changes in rCBF. In the search for changes in rCBF in the areas for auditory processing, three regions of interest (ROI) were selected; primary auditory area, auditory association area and Broca's area. The correlation between the rCBF changes in the ROIs and the speech perception performances was analyzed using Pearson's correlation coefficient. RESULTS: The patient's speech perception performances ranged widely. Although there were no significant correlations between the speech perception and the rCBF increases in the primary auditory area and Broca's area, there were positive correlations in the auditory association area. In the left auditory association area, the correlation coefficient of the vowel perception performance was 0.546 (P <0.05) and that of the speech-tracking test was 0.657 (P < 0.05). Regarding the consonant perception performance, the correlation coefficient was 0.743 (P < 0.01). There was a positive correlation only between the consonant perception performance and the rCBF increase (R = 0.576, P < 0.05) in the right auditory association area. These correlations are stronger in the left hemisphere than in the right hemisphere. CONCLUSIONS: It is suggested that the improvement of the auditory processing of speech in CI users with SPEAK strategy is accompanied by the recruitment of more neurons in the auditory association areas. The adult auditory cortices may still have plasticity or

Adult↗

PubMed1998

[Cochlear implantation in deaf children].

OBJECTIVE: To evaluate the results of cochlear implantation in deaf children. DESIGN: Descriptive. SETTING: Ear, nose and throat department, Academic Hospital, Nijmegen, and Institute for the Deaf St. Michielsgestel, the Netherlands. METHODS: The results in 29 totally deaf children implanted with a 22-channel Nucleus implant--partly in a project supported by the National Fund for Investigative Medicine--in the period 1990-1996 were determined. Six of the children had congenital deafness, the others were deaf as a sequel to meningitis. The operation had no serious complications. All children were followed for at least two years. Progress in auditory perception and speech-language development were measured with structured tests. RESULTS: There was a marked improvement in auditory performance, and language development (measured with Reynell test), although the level of normal hearing children was not reached by most of the operated children. The results were better for children with total insertion of the electrodes than for those with partial insertion (n = 4); of these last, one stopped using the implant. CONCLUSION: Cochlear implantation can limit the consequences of total deafness in children.

Adolescent↗