SEARCH · PubMed Health

Results for “Cochlear Implants”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,549 records · Page 86Linked to original sources

PubMed1997

Comparative study of English- and German-speaking children with the Clarion cochlear implant.

OBJECTIVE: To compare the performance of English-speaking and German-speaking children with Clarion cochlear implants on the Meaningful Auditory Integration Scale (MAIS). SUBJECTS AND METHODS: Prelingually deafened German-speaking children and English-speaking children with Clarion cochlear implants were assessed on the MAIS pre- and postoperatively. Data were analyzed in terms of the absolute score, preoperatively and at two postoperative intervals, and the improvement score. RESULTS AND DISCUSSION: Preoperatively, the MAIS scores of German-speaking children were slightly lower than those of English-speaking children. Postoperatively, this difference became more pronounced. Substantial deviation within each group of subjects was suggested by the size of the standard deviations.

Adolescent↗

PubMed1991

Labyrinthitis ossificans: histopathologic consideration for cochlear implantation.

Labyrinthitis ossificans may be a hindrance to cochlear implantation by making electrode insertion difficult. We performed a histopathologic study of 24 temporal bones with labyrinthitis ossificans from multiple causes. The organ of Corti was graphically reconstructed and the degree of obstruction was estimated for each millimeter of the cochlea. Correlations were calculated between the degree of new bone formation and the cause, patient's age and sex, and time from the original temporal bone insult. Our results demonstrate that complete cochlear ossification is rare. The scala tympani in the basal turn of the cochlea is the most frequent area of ossification, regardless of the cause of the labyrinthitis ossificans. Meningogenic labyrinthitis, usually a childhood disease, was associated with the greatest amount of ossification. When ossification resulted from tympanogenic labyrinthitis, the scala tympani was completely ossified near the round window niche in all temporal bones. Neo-ossification of the basal turn associated with otosclerosis was limited to the proximal 6 mm of the scala tympani in all cases. Three temporal bones had a patent round window niche and basal turn, but significant apical and middle-turn ossification. Peripheral sensorineural elements were severely degenerated in the region of the ossification in all specimens, and spiral ganglion cell counts were decreased.

Adolescent↗

PubMedDate not supplied

Considerations for cochlear implantation of children with sudden, fluctuating hearing loss.

The histories of two pediatric patients who received cochlear implants with subsequent partial recovery of hearing in the nonimplanted ear are reviewed. One child had a sudden bilateral hearing loss, presumably secondary to autoimmune ear disease. The other child had a bilateral progressive hearing loss diagnosed as large vestibular aqueduct syndrome (LVAS). The rationale for the timing of the surgical implantation is discussed. Retrospectively, recovery of hearing in the nonimplanted ear suggests the possibility that the implant could have been delayed or eliminated as a treatment option, and that wearable hearing aids may have been appropriate. A number of factors, however, suggest the decision to implant was appropriate. Issues involved in the decision-making process of when to implant are presented and discussed.

Adolescent↗

PubMed2003

Cochlear implants: some likely next steps.

The history of cochlear implants is marked by large improvements in performance, especially over the past two decades and especially due to the development of ever-better processing strategies. Although the progress to date has been substantial, present devices still do not restore normal speech reception, even for top performers and particularly for listening to speech in competition with noise or other talkers. In addition, a wide range of outcomes persists, with some patients receiving little benefit using the same devices that support high levels of speech reception for others. The purpose of this review is to describe some likely possibilities for further improvement, including (a) combined electric and acoustic stimulation of the auditory system for patients with significant residual hearing, (b) use of bilateral implants, (c) a closer replication with implants of the processing steps in the normal cochlea, and (d) applications of knowledge about factors that are correlated with outcomes to help patients presently at the low end of the performance scale.

Acoustic Stimulation↗

PubMedDate not supplied

Otitis media in children following the cochlear implant.

Children are more prone to otitis media than adults. Therefore, although otitis media has not produced any complications in adult cochlear implant patients, concern has been expressed that it might do so in children with an implant. This study examined the frequency and severity of otitis media following cochlear implantation. Data were collected from parents and physicians by use of a questionnaire. In addition, medical records were examined for incidence and severity of otitis media or any evidence of inner ear infection. All parents and all physicians who responded to the questionnaire rated both the frequency and severity of otitis media as the same or decreased after implantation when compared to preimplant. Medical records show no evidence that incidence of otitis media is affected by the implant.

Child↗

PubMed2005

The influence of a sensitive period on central auditory development in children with unilateral and bilateral cochlear implants.

We examined the longitudinal development of the cortical auditory evoked potential (CAEP) in 21 children who were fitted with unilateral cochlear implants and in two children who were fitted with bilateral cochlear implants either before age 3.5 years or after age 7 years. The age cut-offs (<3.5 years for early-implanted and >7 years for late-implanted) were based on the sensitive period for central auditory development described in [Ear Hear. 23 (6), 532.] Our results showed a fundamentally different pattern of development of CAEP morphology and P1 cortical response latency for early- and late-implanted children. Early-implanted children and one child who received bilateral implants by age 3.5 years showed rapid development in CAEP waveform morphology and P1 latency. Late-implanted children showed aberrant waveform morphology and significantly slower decreases in P1 latency postimplantation. In the case of a child who received his first implant by age 3.5 years and his second implant after age 7 years, CAEP responses elicited by the second implant were similar to late-implanted children. Our results are consistent with animal models of central auditory development after implantation and confirm the presence of a relatively brief sensitive period for central auditory development in young children.

Acoustic Stimulation↗

PubMed2005

Relationships among professionals' knowledge, experience, and expectations regarding cochlear implants.

THE PRESENT STUDY examined the relationships between teachers' and communication clinicians' self-reported knowledge on cochlear implants and their expectations of CIs. The authors also explored these professionals' views regarding the child's communication mode, educational setting, and social options following cochlear implantation. The participants were 47 teachers of deaf students and 35 communication clinicians. The results showed that there were no significant differences between the two groups in self-reported knowledge on CI. Both groups knew very little about mapping, costs, or insurance, and reported good knowledge about candidacy. Expectations from CIs were moderate to high, and were significantly related to respondents' knowledge and specific experience with CIs. Most professionals in both groups supported spoken-language communication, individual inclusion, and social exposure to children with normal hearing as well as to children with hearing impairments.

Adolescent↗

PubMed2000

Effect of stimulation rate on phoneme recognition by nucleus-22 cochlear implant listeners.

This study investigated the effect of pulsatile stimulation rate on medial vowel and consonant recognition in cochlear implant listeners. Experiment 1 measured phoneme recognition as a function of stimulation rate in six Nucleus-22 cochlear implant listeners using an experimental four-channel continuous interleaved sampler (CIS) speech processing strategy. Results showed that all stimulation rates from 150 to 500 pulses/s/electrode produced equally good performance, while stimulation rates lower than 150 pulses/s/electrode produced significantly poorer performance. Experiment 2 measured phoneme recognition by implant listeners and normal-hearing listeners as a function of the low-pass cutoff frequency for envelope information. Results from both acoustic and electric hearing showed no significant difference in performance for all cutoff frequencies higher than 20 Hz. Both vowel and consonant scores dropped significantly when the cutoff frequency was reduced from 20 Hz to 2 Hz. The results of these two experiments suggest that temporal envelope information can be conveyed by relatively low stimulation rates. The pattern of results for both electrical and acoustic hearing is consistent with a simple model of temporal integration with an equivalent rectangular duration (ERD) of the temporal integrator of about 7 ms.

Adult↗

PubMed1992

Speech changes following reimplantation from a single-channel to a multichannel cochlear implant.

The speech of a postlingually deafened preadolescent was recorded and analyzed while a single-electrode cochlear implant (3M/House) was in operation, on two occasions after it failed (1 day and 18 days) and on three occasions after stimulation of a multichannel cochlear implant (Nucleus 22) (1 day, 6 months, and 1 year). Listeners judged 3M/House tokens to be the most normal until the subject had one year's experience with the Nucleus device. Spectrograms showed less aspiration, better formant definition and longer final frication and closure duration post-Nucleus stimulation (6 MO. NUCLEUS and 1 YEAR NUCLEUS) relative to the 3M/House and no auditory feedback conditions. Acoustic measurements after loss of auditory feedback (1 DAY FAIL and 18 DAYS FAIL) indicated a constriction of vowel space. Appropriately higher fundamental frequency for stressed than unstressed syllables, an expansion of vowel space and improvement in some aspects of production of voicing, manner and place of articulation were noted one year post-Nucleus stimulation. Loss of auditory feedback results are related to the literature on the effects of postlingual deafness on speech. Nucleus and 3M/House effects on speech are discussed in terms of speech production studies of single-electrode and multichannel patients.

Child↗

PubMed2005

Cochlear implantation in a human immunodeficiency virus-infected patient.

OBJECTIVES/HYPOTHESIS: Patients infected with HIV have an increased risk of developing sensorineural hearing loss (SNHL), yet pathogenesis of SNHL in HIV infection is still poorly understood. In subjects affected by bilateral profound or total SNHL, cochlear implantation may be the only possibility to restore a hearing level that allows them to have an acceptable quality of life. STUDY DESIGN: Case report. METHODS: A retrospective chart review of a HIV type 1-seropositive profoundly deafened patient who underwent cochlear implantation. RESULTS: To date, with a follow-up of 4 years, the patient has not experienced any complication and has regained useful open-set speech perception. CONCLUSIONS: Cochlear impairment with preserved auditory pathways can be responsible for profound SNHL in HIV-infected patients. Cochlear implantation can restore a social hearing in these patients, dramatically improving their quality of life. The surgical procedure can be safely performed when keeping in mind that the general condition of the patient is the decisive factor for or against surgery.

Adult↗

PubMed1996

Ethics of cochlear implantation in young children.

Certain leaders of the Deaf community are attempting to generate opposition to cochlear implants in children by pitting the rights of deaf children and their families against the needs of deaf society. They have labeled physicians as unethical and CIs as "child abuse," resulting in misunderstanding, anger, and violence. However, the arguments of these leaders are internally contradictory: they hold that deafness is not a disability but support disability benefits for the deaf; they maintain both that cochlear implants do not work and that they work so well that they are "genocidal" (i.e., they will eliminate deafness). Their positions oppose the ethical principles of beneficence and autonomy as they relate to self-determination and privacy. Ethical standards hold that the best interests of the child precede those of a special interest group and that parents have the responsibility to determine their children's best interests.

Child↗

PubMedDate not supplied

Of kittens and kids: altered cortical maturation following profound deafness and cochlear implant use.

Profoundly deaf children who use a cochlear implant (CI) provide a unique opportunity to investigate the effects of auditory sensory deprivation on the maturing human central nervous system. Previous results suggest that children fitted with a CI show evidence of altered auditory cortical maturation, based on evoked potentials. This altered maturation was characterized by both latency delays and morphological changes in the cortical auditory evoked potentials (AEPs). Based on prolonged P(1) latencies compared to age-matched normal-hearing (NH) peers, these data suggested a delayed maturation nearly equivalent to the period of deafness. However, rates of maturation for this AEP peak were essentially the same in NH and CI children. This suggests that, given enough time, the AEPs of CI children would assume the characteristic morphology found in older NH teens and NH adults. However, the data also indicated a substantial alteration of the typical set of obligatory P(1)-N(1b)-P(2) peaks, specifically related to the absence of the N(1) potential. Recent analyses of more extensive sets of longitudinal and cross-sectional data indicate that even after many years of implant use, the AEPs of CI users in their late teens remain very different from those of their NH peers. The P(1) peak latency remains prolonged and P(1) amplitude remains much larger in CI users than in age-matched NH teens. These findings suggested that age-related changes in the P(1) peak are completed by 12 years of age. In addition, the normal N(1b) peak fails to emerge in virtually all of the CI children tested in our laboratory. A major new interpretation of the abnormal maturation of AEP waveforms in CI children is presented. It is based on direct evidence showing that a persistent immaturity of the superficial layer axons has persistent negative effects on the generation of the N(1b) and, consequently, on the morphology of the AEPs. A comparison of scalp-recorded AEPs from implanted children with local field potentials measured from the cortical surface in deaf white kittens suggests the effects of deafness and CI use are similar across these mammalian species. For both species, a period of profound deafness followed by CI stimulation reveals a substantial immaturity in cortical activation even after a period of electrical stimulation by the CI.

Animals↗

PubMed2004

Effect of age at cochlear implantation on auditory skill development in infants and toddlers.

OBJECTIVES: To investigate the effect of age at cochlear implantation on the auditory development of children younger than 3 years and to compare these children's auditory development with that of peers with normal hearing. DESIGN: Using a repeated-measures paradigm, auditory skill development was evaluated before and 3, 6, and 12 months after implantation. Data were compared with previously published data from cohorts with normal hearing. PARTICIPANTS: One hundred seven hearing-impaired children (age range, 12-36 months) who received a cochlear implant during clinical trials in North America. MAIN OUTCOME MEASURE: Auditory skill development was assessed using the Infant-Toddler Meaningful Auditory Integration Scale, a tool that provides a quantitative measure in children as young as newborns. RESULTS: Infants and toddlers who receive implants show rapid improvement in auditory skills during the first year of device use regardless of age at implantation, although younger children achieve higher scores. Children who undergo implantation at a younger age acquire auditory skills nearer to those of their peers with normal hearing at a younger age. The mean rate of acquisition of auditory skills is similar to that of infants and toddlers with normal hearing regardless of age at implantation. CONCLUSION: Performing implantation in children with profound hearing loss at the youngest age possible allows the best opportunity for them to acquire communication skills that approximate those of their peers with normal hearing.

Age Factors↗

PubMed2004

[The changes in the distinctness and discrimination of phonems of cochlear implants children].

Hearing impaired children do not develop oral speech in the same time with the hearing ones. Cochlear implants may change this situation. Implanted deaf children may develop oral speech but only after long speech rehabilitation. Acquisition of language skills should be assesed correctly in every patient. It is important because this therapy is quite expensive. There are many quantitative and qualitative methods used all over the world. In some cases score is calculated as percentage of correctly repeated words. Sometimes it did not reflect true level of language development. 240 people were implanted in Poznań in years 1994-2004. Two years ago, evaluation of changes in the distinctness and discrimination of phonems of cochlear implants children was begun. We found differences between standard speech audiometry and distinctness and discrimination of phonems.

Child↗

PubMed2002

[Preoperative cochlear implantation imaging].

OBJECTIVE: To investigate the value of CT and MRI as preoperative imaging technique for cochlear implant candidates. METHOD: Axial high-resolution temporal bone CT and T2-weighted FSE-MRI were performed in 26 patients with sensorineural hearing loss. Three-dimensional reconstruction of inner ear was compared between CT and MRI. RESULT: There were 1 case (2 ears) with Mondini malformation type I , 1 case (2 ears)with Mondini malformation type II , 1 case (2 ears) with inner fibrosis in 18 patients with congenital sensorineural hearing loss. There were 1 case (2 ears) with chronic suppurative otitis meadia, 1 case (2 ears) with inner ossification in 5 patients with postlingually deafness. CONCLUSION: CT plays an indispensable role in evaluation of cochlear implantation. T2-weighted FSE-MRI is necessarily complementary to CT. MRI three-dimensional reconstruction of inner ear is better than CT.

Adolescent↗

PubMed1997

Cochlear implant studies at Research Triangle Institute and Duke University Medical Center.

Examples from several areas of cochlear implant research are presented, with emphasis on the continuous interleaved sampling (CIS) approach to speech processor design. Within-subject comparisons of such processors with the compressed analog (CA) approach of the clinical Ineraid device are reviewed, and ongoing similar comparisons with the clinical Nucleus spectral peak (SPEAK) strategy are outlined. Correlations between chronic performance levels with clinical CA processors and initial performance levels with CIS, data on further improvements in performance with chronic use of CIS, and instances of substantial benefit from custom fitting of CIS parameters are presented as examples of findings with immediate clinical implications. New studies are described, involving the measurement of intracochlear evoked potentials in response to cochlear implant stimulation, and the integration of such work with computer modeling studies.

Cochlear Implants↗

PubMed1990

[Changes of the threshold level in patients with 22-channel cochlear implant].

Psychophysical responses of the patients to electrical stimulation were examined in order to clarify long-term effects of the cochlear implant in 9 patients who had received a 22-channel cochlear implant. Measured items were the minimal threshold level (T-level), the maximum comfortable level (C-level), and the dynamic range between T- and C-level. Measurements were repeated for each electrode every three months over more than 6 months. Following results were obtained. 1) The changes of the T-level were classified into four types as follows, a type with no change, a type with gradual decrease, a type with decrease in two to three months followed by gradual increasing threshold and a type with gradual increasing just after surgery. Even in a last type, the maximum increase in the T-level did not exceed 200 microA and, in most cases, these changes were stabilized within a few months after implantation. 2) The dynamic range gradually increased. It was obvious in both in the middle and apical electrodes, while such increased threshold was not observed in the basal electrodes. 3) In some cases, a few basal electrodes could not been used since they caused uncomfortable sensation or those dynamic ranges became below a certain extent. As a result, it was suggested that the electrical stimulation had not induced serious degeneration of the ganglion cells and the auditory nerve fibers. The reduction in the number of usable electrodes might be due to the surgical trauma to the intracochlear tissue. Therefore, exposing of the scala tympani should be minimal in order to avoid the damage of the cochlea.

Adult↗

PubMed1996

[Comparison of speech perception with cochlear implant and hearing aid--analysis according to speech strategy and hearing level].

This study was carried out to compare the speech perception ability of patients using hearing aids with hearing levels of 81dB or more (55 patients) and those with cochlear implants (67 patients). The patients with hearing aids were divided into group A (hearing levels 81-90dB, 7 patients), group B (91-100dB, 11 patients), group C (101-110dB, 19 patients), group D (111-120dB, 7 patients), and group E (121-130dB, 6 patients). The patients with cochlear implants were using the strategies of F0F1F2 (14 patients), MPEAK (32 patients) and SPEAK (21 patients). Speech perception tests of monosyllables, words, and sentences under conditions of auditory plus vision were administered. The means and standard deviations of percentages giving the correct answer in F0F1F2, MPEAK and SPEAK were 45.2 +/- 14.7%, 45.7 +/- 14.6% and 62.6 +/- 15.9% for monosyllables, 44.8 +/- 18.9%, 56.3 +/- 15.0% and 73.4 +/- 15.5% for words, and 64.0 +/- 26.4%, 60.5 +/- 15.9% and 84.7 +/- 13.8% for sentences. In comparison with the results for patients with hearing aids, and speech perception for F0F1F2 and MPEAK was equivalent to that of group C, and that for SPEAK was better than that of group B but poorer than that of group A. In other words, the speech perception ability in conventional cochlear implant strategies--F0F1F2 and MPEAK--corresponded to that of patients with hearing levels of 101-110dB, but that in the new strategy, SPEAK, gave better results than 91-100dB.

Adolescent↗