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PubMed2001

Beginning to talk at 20 months: early vocal development in a young cochlear implant recipient.

Early vocal development, consonant production, and spoken vocabulary were examined in a deaf toddler whose multichannel cochlear implant was activated at 20 months. Parent-child interactions were recorded before implantation and at monthly intervals during the first year of implant use. The child's utterances were classified according to developmental levels from the Stark Assessment of Early Vocal Development. The emergence of consonant types and consonant features were documented through listener transcription. Parent reports were used to monitor oral vocabulary growth. A large increase in canonical and postcanonical utterances was observed after 5 months of implant use, and these advanced prelinguistic forms were dominant in all subsequent recording sessions. Increases in the diversity of consonant types and features suggested that auditory information was used to increase phonetic diversity. It was reported that the child understood almost 240 words and spoke approximately 90 words after one year of implant experience. The combination of cochlear implantation at a young age, family support, and regular intervention appeared to facilitate efficient early vocal development and gains in spoken vocabulary.

Age Factors↗

PubMed1993

Clarion cochlear implant: phase I investigational results.

Under phase I of an FDA-approved Investigational Device Exemption (IDE), six patients at the University of California, San Francisco (UCSF) have been implanted with the Clarion, a new multichannel, multiprogrammable cochlear implant system. Over a period of 5 years, the Clarion has been collaboratively developed by UCSF, the Research Triangle Institute (RTI) of North Carolina, and the device manufacturer and sponsor, MiniMed Technologies of Sylmar, California. For UCSF, it represents the culmination of 21 years of cochlear implant research. The Clarion incorporates the 16-contact electrode array developed at UCSF. This electrode is designed with a gentle curve and an elastic memory that allow it to hug the modiolar wall of the scala tympani. In addition, the electrode has mechanical features that prevent it from rotating upward and injuring the basilar membrane. One of the innovations necessary to allow broad clinical application of this device has been the development of an electrode insertion tool to assist the surgeon in safe placement. In each of the six UCSF cases, the insertion tool was used and electrode placement was achieved with ease. With the availability of a variety of speech processing strategies, the Clarion has also provided the opportunity for all of the patients tested to date to achieve some degree of open-set, auditory-only speech recognition. Surgical considerations and preliminary audiologic data demonstrate that the design rationale and objectives of the Clarion have been met.

Aged↗

PubMed1995

A clinical report on speech production of cochlear implant users.

OBJECTIVE: The aim was to assess articulation and speech intelligibility over time in a group of cochlear implant users implanted at 8 yr or over. The hypothesis was that the postoperative speech production performance would be greater than the preoperative performance. DESIGN: A test of intelligibility using sentences and an articulation test measuring non-imitative elicited speech were administered to 11 and 10 subjects, respectively, who were implanted with the 22-electrode cochlear implant. Nine subjects received both tests. Age at implantation ranged from 8 yr to 20 yr and implant use ranged from 1 yr to 4 yr 5 mo. RESULTS: For both the intelligibility and articulation tests roughly half of the subjects showed significant improvements over time and group mean postoperative performance significantly exceeded preoperative performance. Improvements occurred for front, middle, and back consonants; for stops, fricatives, and glides and for voiceless and voiced consonants. CONCLUSIONS: Despite being deprived of acoustic speech information for many childhood years, roughly half of the patients assessed showed significant gains in speech intelligibility and articulation postimplantation. The lack of a control group of non-implanted patients means that we cannot separate out the influence of the implant on speech production from other influences such as training and tactile-kinaesthetic feedback.

Adolescent↗

PubMed2005

Cochlear implantation in rats: a new surgical approach.

The laboratory rat has been used extensively in auditory research but has had limited use in cochlear implant related research due mainly to the surgically restricted access to the scala tympani. We have developed a new surgical method for cochlear implantation in rats. The key to this protocol was cauterizing the stapedial artery (SA) and making a small cochleostomy near the round window in order to enlarge the surgical access to the scala tympani. Five normal hearing Hooded Wistar rats were used to investigate the effect of cauterizing the SA on hearing and auditory nerve survival. Results showed that cauterizing the SA was surgically feasible, afforded excellent exposure of the round window niche for cochleostomy, and did not adversely affect acoustic thresholds measured electrophysiologically. Moreover, there was no difference in spiral ganglion cell densities for any cochlear turn when compared with the contralateral control ears. Three deafened rats were subsequently implanted with a scala tympani electrode array using this new surgical approach. Electrically evoked auditory brainstem responses using bipolar stimulation, and subsequent cochlear histopathology demonstrated that cochlear implantation using a custom-made rat electrode array was safe and effective. The surgical approach presented in this paper presents a safe and effective procedure for acute or chronic cochlear implantation in the rat model.

Animals↗

PubMed2005

Cochlear implantation in children with Waardenburg syndrome.

Waardenburg syndrome is an autosomal-dominant trait resulting from mutations occurring in different genes. It is often characterized by varying degrees of: congenital hearing loss; dystopia canthorum; synophrys; broad nasal root; depigmentation of hair (white forelock), skin or both; and heterochromic or hypochromic irides. A retrospective case study was done to assess speech perception, speech production, general intelligence and educational setting in six profoundly hearing-impaired children with Waardenburg syndrome (four with type I, one with type II and one with type III) ranging in age from two years to 14 years, seven months (mean = six years, six months). None of the patients had malformation of the cochlea and were implanted using Nucleus 22/24 and Med-el combi40+. Five out of the six cases were of average intelligence and one had a borderline intelligence quotient. The follow-up period ranged from one year, 10 months to six years, six months (mean = three years, six months) after implantation. The evaluation of auditory perception in patients was accomplished using the Persian Auditory Perception Test for the Hearing-Impaired, a Persian Spondee words test and the Categories of Auditory Performance Index. The Speech Intelligibility Rating test was used to evaluate speech production ability. All the patients' speech perception and speech intelligibility capabilities improved considerably after receiving the implants, and they were able to be placed in regular educational settings. Patients used their cochlear-implant devices whenever awake, implying that they benefitted from the devices. We suggest that any further expansion of cochlear-implantation criteria in children include those with Waardenburg syndrome.

Adolescent↗

PubMed1989

Antibiotic prophylaxis in cochlear implantation: current practice.

A postal survey examined the current use of prophylatic antibiotics during cochlear implantation. Seventeen centres, worldwide, replied giving details on 1030 cochlear implant operations: 56.4 per cent were implanted with antibiotic prophylaxis and 43.6 per cent without; 2.9 per cent of devices were removed because of infection, 4.5 per cent of those with prophylaxis and 0.9 per cent of those without. Most cases of infection were associated with technical problems in the design or the positioning of the device. No cases of meningitis were reported. Routine antibiotic prophylaxis does not appear to offer any benefit.

Anti-Bacterial Agents↗

PubMed2000

Cochlear implantation in Jervell and Lange-Nielsen syndrome.

Jervell and Lange-Nielsen syndrome represents a rare, autosomal recessive cause of congenital deafness. Affected patients have a characteristic prolongation of the QT interval on electrocardiogram, along with cardiac arrhythmias, recurrent syncopal episodes, and a predisposition to sudden death. We present the first reported case of cochlear implantation in a child with Jervell and Lange-Nielsen syndrome. Special perioperative precautions were required, including cardiac monitoring for 48 hours, perioperative beta blockade, and special anesthetic considerations. Because sudden patient death has been associated with exposures to loud sounds in patients with prolonged QT syndrome without hearing loss (Ward-Romano syndrome), initial cochlear implant stimulation was performed with cardiac monitoring. This patient has responded well to cochlear implantation with 11 months of implant use. The patient has achieved limited open-set word comprehension and significantly improved speech, as is expected for her age. Although the patient had no problems with cardiac arrhythmias at surgery, she has since experienced a syncopal episode requiring placement of an automatic pacemaker and defibrillator. The implant has continued to work well despite the pacemaker and defibrillator. Cochlear implantation can be relatively safely performed in patients with Jervell and Lange-Nielsen syndrome, provided proper precautions are followed.

Child, Preschool↗

PubMed1992

[The cochlear implant in childhood. Possibilities, limits and perspectives of management].

Therapeutic experiences with cochlear implants in late adult deafness have become so large that implants now belong to the accepted methods of therapy for profoundly deaf patients. Affected patients often recognize speech through simple auditory means. In the last 5 years increased numbers of children with congenital or infantile deafness have also been successfully treated with cochlear implants. Some reports have already been published about clinical experiences and rates of success. In this paper some positive results are shown, but the limitations of treatment and the necessity for accurate preoperative diagnosis must be understood. The further development of treatment for deaf implants requires refinements in phoniatric and pedaudiological techniques.

Adolescent↗

PubMed2004

Speech recognition with a cochlear implant using triphasic charge-balanced pulses.

OBJECTIVE: Typically, symmetrical charge-balanced biphasic current pulses are used in cochlear implants to ensure biological safety. Theoretically, monophasic pulses are more effective, but potentially noxious, stimuli. In this study we charge-balanced such monophasic pulses during selected non-stimulated intervals, effectively leading to triphasic pulses with a 4:1 amplitude ratio between the cathodic and anodic phases. Apart from ensuring safety, this is also expected to reduce power consumption and channel interaction. MATERIAL AND METHODS: Seven experienced Clarion CII cochlear implant users with a multichannel (12-16 channels) monopolar continuous interleaved sampling (CIS) strategy participated in the study. Three different CIS strategies were fitted using the Clarion Research Interface (CRI-2). The reference was an implementation of each subject's own CIS program. The two strategies tested used triphasic pulses on the same channels, one with half-wave rectification (TP-HWR) and one without rectification (TP-NoR) at the input. Directly after fitting (i.e. without any training), speech perception (phoneme score on consonant-vowel-consonant words) was measured in silence (sound-only) and in speech-shaped background noise with signal:noise ratios (SNRs) of +5 and 0 dB. RESULTS: Speech perception with the reference via the CRI-2 was equal to that of the free-field condition with the subjects' own speech processor. With the TP-NoR strategy, speech perception improved significantly (from 89% to 93%) in silence and in the 0-dB SNR condition (from 43% to 49%). With a SNR of +5 dB, performance was stable at approximately 66%. With the TP-HWR strategy, performance increased significantly in the 0- and +5-dB SNR conditions, to 55% and 74%, respectively. Power consumption was reduced in both strategies, to 30% and 36% for TP-HWR and TP-NoR, respectively. CONCLUSION: The new triphasic strategies are most promising, with respect to both their improved speech perception and reduced power requirements. The optimal parameters will have to be identified following long-term use.

Adult↗

PubMed1999

Meta-analysis of pediatric cochlear implant literature.

We analyzed published reports of the effect of age at implantation and the cause of and age at onset of deafness on speech perception benefit in children with cochlear implants, and compared these results with those of unreported trials of multichannel cochlear implants. Combining data from published and unpublished patient series was constrained by differences in test protocols between studies, but was made feasible by employing a meta-analysis in which data were converted into an ordinal classification scale that represented levels of communicative benefit. Results showed that more rapid gains in speech perception are associated with earlier age at implantation, and that speech perception results are independent of cause of or age at onset of deafness after 1 year of implant use. Moreover, with minor exceptions, there was no statistical difference between published and unpublished data, thereby indicating no publication bias in the literature. A meta-analytic approach is useful because it can clarify the quality of reported data and the direction of future research and, hopefully, foster collaboration in conducting and reporting future research. A standardized approach to reporting results in children is advised in order to produce a balanced interpretation of implant benefit and to facilitate wider understanding and dissemination of study conclusions.

Age Factors↗

PubMed2007

Implication of central asymmetry in speech processing on selecting the ear for cochlear implantation.

OBJECTIVE: Emerging evidence in auditory neuroscience suggests that central auditory pathways process speech asymmetrically. In concert with left cortical specialization for speech, a "right-ear advantage" in speech perception has been identified. The purpose of this study is to determine if this central asymmetry in speech processing has implications for selecting the ear for cochlear implantation. STUDY DESIGN: Retrospective cohort study. SETTING: Academic university medical center PATIENTS: One hundred one adults with bilateral severe-to-profound sensorineural hearing loss INTERVENTION: Cochlear implantation with the Nucleus 24 Contour device. MAIN OUTCOME MEASUREMENTS: Patients were divided into two groups according to the ear implanted. Results were compared between left-ear- and right-ear-implanted patients. Further subgroup analysis was undertaken, limited to right-handed patients. Postoperative improvement on audiograms and scores on speech perception tests (Hearing in Noise test, City University of New York in quiet and in noise test, Consonant-Vowel Nucleus- Consonant words, and phonemes) at 1 year was compared between groups. Analysis of covariance was used to control for any intergroup differences in preoperative characteristics. RESULTS: The groups were matched in age, duration of hearing loss, duration of hearing aid use, percentage implanted in the better hearing ear, and preoperative audiologic testing. Postoperatively, there were no differences between left-ear- and right-ear-implanted patients in improvement on speech recognition tests. CONCLUSION: Despite central asymmetry in speech processing, our data do not support a right-ear advantage in speech perception outcomes with cochlear implantation. Therefore, among the many factors in choosing the ear for cochlear implantation, central asymmetry in speech processing does not seem to be a contributor to postoperative speech recognition outcomes.

Adolescent↗

PubMed1991

Speech perception abilities of children with cochlear implants, tactile aids, or hearing aids.

The purpose of this experiment was first, to compare the performance of three matched groups of experimental subjects who used either a single-channel cochlear implant, a multichannel cochlear implant, or a two-channel vibrotactile aid on a battery of speech perception measures, and second, to compare the performance of subjects with residual hearing who used hearing aids to that of the three groups of experimental subjects. The results revealed that the subjects using hearing aids achieved the highest scores on all measures. The performance of the group of multichannel implant users was significantly higher than that of the single-channel implant users on tests involving discrimination of speech features, categorization of stress patterns, closed-set identification of familiar words, and identification of common phrases with and without visual cues. The performance of the subjects using 3M/House and Tactaid II devices was similar on all tests except those requiring integration of auditory or tactile cues and visual cues, on which the 3M/House device users achieved significantly higher scores than did the Tactaid II device users.

Adolescent↗

PubMed2002

The relationship between the intraoperative ECAP threshold and postoperative behavioral levels: the difference between postlingually deafened adults and prelingually deafened pediatric cochlear implant users.

The purpose of this study was to determine the relationship between electrically evoked compound-action potential (ECAP) thresholds, electrically evoked auditory brain-stem response (EABR) thresholds, behavioral thresholds (T levels) and maximum comfort levels (C levels) in profoundly deaf cochlear-implant users. The ECAP thresholds were measured intraoperatively in eight postlingually deafened adults and nine (eight prelingually and one postlingually deafened) children implanted with the Nucleus CI24 M cochlear implant. The mean ECAP thresholds did not differ between children and adults. The average behavioral T and C levels after at least 6 months of experience with a cochlear implant were significantly higher in children than those in adults. The ECAP thresholds were more strongly correlated with T and C levels in children than in adults. The stronger correlation between ECAP thresholds and behavioral T and C levels in children than in adults might result from differences in loudness sensation, which should in turn depend on auditory experience.

Adult↗

PubMed2005

Influence of voice similarity on talker discrimination in children with normal hearing and children with cochlear implants.

The perception of voice similarity was examined in 5-year-old children with normal hearing sensitivity and in pediatric cochlear implant users, 5-12 years of age. Recorded sentences were manipulated to form a continuum of similar-sounding voices. An adaptive procedure was then used to determine how acoustically different, in terms of average fundamental and formant frequencies, 2 sentences needed to be for a child to categorize the sentences as spoken by 2 different talkers. The average spectral characteristics of 2 utterances (including their fundamental frequencies) needed to differ by at least 11%-16% (2-2.5 semitones) for normal-hearing children to perceive the voices as belonging to different talkers. Introducing differences in the linguistic content of the 2 sentences to be compared did not change performance. Although several children with cochlear implants performed similarly to normal-hearing children, most found the task very difficult. Pediatric cochlear implant users who scored above the group mean of 64% of words correct on a monosyllabic open-set word identification task categorized the voices more like children with normal hearing sensitivity.

Child↗

PubMed2004

Meningitis in cochlear implant recipients: the North American experience.

INTRODUCTION: Until recently, postimplant meningitis was infrequently reported and felt to be uncommon. However, in the spring of 2002, there was a sudden increase in the number of reported cases of postimplantation meningitis in both Europe and North America. OBJECTIVE: Because complications of surgery often tend to be underreported, we decided to survey all cochlear implant centers in North America to determine the true incidence of postimplant meningitis and to learn more about the demographics and risk factors. STUDY DESIGN: We conducted a prospective study. A survey instrument was designed asking surgeons the number of implants performed and whether they had seen any cases of meningitis after implantation. If the answer was affirmative, they were asked to respond to a 20-point questionnaire. This instrument was sent to all 401 cochlear implant centers in North America. SETTING: Tertiary care referral centers. PATIENTS: We studied all patients having received cochlear implants in North America. MAIN OUTCOME MEASURES: Number of cases of postimplant meningitis, age of patients, device used, cochlear and temporal bone abnormalities, treatment, and outcomes. RESULTS: Meningitis is more common than previously thought. Risk factors included young age, cochlear dysplasia, temporal bone abnormalities, and the use of a two-part electrode system. This survey led to the involvement by the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention in a much more intensive analysis of a subset of the cases. CONCLUSIONS: Postimplant meningitis is related to patient, surgical, and device factors. By being aware of the risk factors involved, adhering to sound surgical principles such as packing of the cochleostomy with soft tissue, appropriately vaccinating patients, and eliminating any potentially traumatic electrode arrays, the incidence of meningitis should be significantly diminished.

Age Factors↗

PubMed2005

Advantages of binaural hearing provided through bimodal stimulation via a cochlear implant and a conventional hearing aid: a 6-month comparative study.

CONCLUSIONS: Our study data demonstrate the additional benefit derived from continued use of a contralateral hearing aid (HA) post-cochlear implantation for speech recognition ability in quiet and in noise. Postoperative bimodal stimulation is recommended for all subjects who show some speech recognition ability in the contralateral ear as it may offer binaural listening advantages in various listening situations encountered in everyday life. OBJECTIVES: To assess the benefits derived from bimodal stimulation for experienced HA users implanted with a cochlear implant (CI) (score=20% in disyllabic test). The correlation between pre- and postoperative performance on speech perception measures was examined to determine additional criteria for recommending bimodal stimulation postoperatively. MATERIAL AND METHODS: A within-subject repeated-measures design was used, with each subject acting as their own control. Assessments were carried out preoperatively in aided monaural and best-aided conditions and at 6 months postoperatively in CI-alone, contralateral HA-alone and bimodal listening conditions. Speech recognition using Spanish words and sentences materials was assessed at conversational level and for soft speech in quiet. Speech comprehension in noise was assessed using word materials at a signal:noise ratio of +10, for coincident speech in noise and for spatially separated speech in noise. Twelve adult native Spanish subjects with a severe-to-profound hearing impairment who were experienced with optimally fitted conventional amplification and who displayed suboptimal speech understanding preoperatively were enrolled in the study. Preoperatively, conventional amplification was worn by five subjects binaurally and by seven monaurally. RESULTS: Postoperatively, superior speech recognition ability in quiet and in noise for disyllabic words was achieved using bimodal stimulation in comparison to performance for either monaural aided condition. Mean improvement in speech recognition in the bimodal condition was significant over performance in the CI-alone condition for disyllabic words in quiet at 70 (p=0.006) and 55 dB SPL (p=0.028), for disyllabic words in noise at +10 dB with speech and noise spatially separated with the noise source closest to the contralateral HA (S0NHA) (p=0.0005) and when the noise source was closest to the CI ear (S0NCI) (p=0.002). When testing word recognition in noise with speech and noise sources coincident in space, word scores were superior in the bimodal condition relative to the CI-alone condition but this improvement was not significant (p=0.07). The advantages of bimodal stimulation included significant effects of binaural summation in quiet and significant binaural squelch effects in both the S0NHA and S0NCI test conditions. All subjects showed superior performance in the binaural situation postoperatively relative to the best-aided condition preoperatively for one or more test situations.

Adult↗

PubMedDate not supplied

The effects of a cochlear implant on the family of a hearing-impaired child.

PURPOSE: The purpose of this study was to evaluate the effects of a cochlear implant on the family of a hearing-impaired child. A single family was interviewed to answer these research questions: How does the family adapt initially to hearing impairment?, What are the family's concerns before, during, and after the implantation?, and How does the family accept and adjust to the outcomes of the procedure? METHODS: Immediate family members (mother, father, and child) of the child receiving a cochlear implant were interviewed individually three times: before, during, and after implantation using an investigator-designed interview guide. The child's behavior was also observed during a speech therapy session before and after completion of the implantation. FINDINGS: The findings reflect several common themes concerning ambivalence, excitement, fear, anxiety, impatience, and transformation. CONCLUSIONS: The family choosing cochlear implantation progressed through several phases of adaptive responses from before to after the procedure. Implications for nurses working with families during this process are identified.

Adaptation, Psychological↗

PubMed2005

Cochlear implants and quality of life: a prospective study.

OBJECTIVE: To evaluate changes in quality of life, anxiety, and depression after cochlear implantation in adults. DESIGN: Twenty-seven postlingually deafened adults who had received a MED-EL Combi 40+ implant were investigated. One generic Health-Related Quality of Life measure, the SF-36, two disease-specific measures, the Patient Quality of Life Form (PQLF) and the Index Relative Questionnaire Form (IRQF) completed by a near relative to the patient, in addition to a domain specific measure, the Hopkins Symptom Check List 25 items (HSCL-25), were used in a prospective study. The subjects were investigated before surgery and 12 to 15 months after surgery. RESULTS: The scores were significantly better after surgery in four of six categories of the PQLF. In the IRQF, where a family member of the cochlear implant recipient was studied, the scores were significantly better in four of five categories. There was a significant improvement in the HSCL-25 scores after surgery. In the SF-36, only one of eight scales showed significant improvement. CONCLUSIONS: Cochlear implants were associated with statistically significant improvement in quality of life in postlingually deafened adults. The improvements were largest in the categories concerning communication, feelings of being a burden, isolation, and relations to friends and family. The implants also improved the relatives' daily lives. There was a statistically significant reduction in degree of depression and anxiety. Reduction in anxiety and depression was associated with gain in quality of life.

Adult↗