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PubMed2003

Music perception in adult cochlear implant recipients.

OBJECTIVE: To evaluate musical perception in adult cochlear implant (CI) recipients, i.e. perceptual accuracy for pitch, timbre, rhythmic patterns and song identification. MATERIAL AND METHODS: Twenty-nine adult patients were included in this transverse single-center study. Evaluative measures included tests assessing ability to discriminate pitch, rhythm and timbre and to identify nursery songs with and without verbal cues. Performance scores were correlated with duration of deafness, duration of implantation, speech discrimination and musical perception skills. RESULTS: A total of 38% of patients reported that they did not enjoy listening to music with their device and 86% presented lower scores of listening habits after implantation. We found positive correlations between musical background and pitch identification and identification of nursery songs played by piano. We also found positive correlations between speech discrimination and rhythm, timbre and identification of nursery songs with verbal cues. CONCLUSION: Trends in the patterns of correlation between speech and music perception suggest that music patterns are differentially accessible to CI users. New processing strategies may improve this.

Acoustic Stimulation↗

PubMedDate not supplied

Changes in vowel quality in post-lingually deafened cochlear implant users.

The present study addresses the effect of cochlear implantation on vowel production of 20 post-lingually deafened Dutch subjects. All subjects received the Nucleus 22 implant (3 WSP and 17 MSP processors). Speech recordings were made pre-implantation and three and twelve months post-implantation with the implant switched on and off. The first and second formant frequencies were measured for eleven Dutch vowels (monophthongs only) in an h-vowel-t context. Twelve months post-implantation, the results showed an increase in the ranges of the first and second formant frequency covered by the respective vowels when the implant was switched on. The increase in the formant frequency range was most marked for some subjects with a relatively small formant range pre-implantation. Also, at 12 months post-implantation with the implant switched on we found a significant shift of the first and second formant frequency towards the normative values. Moreover, at this time the results showed significantly increased clustering of the respective vowels, suggesting an improvement in the ability to produce phonological contrasts between vowels. Clustering is defined as the ratio of the between-vowel variance of the first and second formant frequency and the within-vowel variance of three tokens of the same vowel.

Adult↗

PubMed2005

Determination of frictional conditions between electrode array and endosteum lining for use in cochlear implant models.

Frictional conditions between the electrode array (in cochlear implants) and the endosteum lining covering the walls of the interior scala tympani structure strongly influence the sliding behaviour of the electrode array. Friction coefficients, determined by a simple but effective method based on the impending slippage model of electrode arrays sliding over the endosteum lining are reported in this paper. In this study, friction coefficients of the Nucleus standard straight and the Contour arrays have been determined with and without lubricants applied on the endosteum lining. In the absence of applied lubricants, friction coefficients were found to be 0.19 for the Nucleus standard straight array and 0.12 for the Contour array. Application of lubricants (glycerin and sorbelene) has the potential to lower the friction coefficient for Nucleus standard straight array (0.12 and 0.15) and for the Contour array (0.04 and 0.08). These results are used in finite element models to predict accurately the trajectories of electrode arrays and sliding contact pressures on cochlear structures to evaluate the likelihood of damage sustained during insertion.

Cochlear Implants↗

PubMed1993

Importance of patient and processor variables in determining outcomes with cochlear implants.

Within-subjects comparisons of processing strategies for cochlear implants are reviewed. Compressed analog strategies were compared to interleaved pulses strategies in tests with one group of 8 subjects, and to continuous interleaved sampling strategies in tests with another group of 11 subjects. The tests included open-set recognition of words and sentences. The results show that, while different strategies may produce quite different outcomes across subjects, individual performances with one processing strategy are significantly correlated with those of alternative strategies. These findings emphasize the importance of patient variables in determining outcomes across a variety of prosthesis designs.

Acoustic Stimulation↗

PubMed1994

[Cochlear implant in a child with congenital severely impaired hearing].

A 6-year 9-month-old child with congenital severely hearing impaired received a Nucleus 22 channel implant. Twenty-two CG electrodes are now in use. In the 5 months since the cochlear implant, the patient has made good progress. Her vowel discrimination score has reached 100%. However, her consonant discrimination has remained at the chance level. On the other hand, auditory reception of environmental sounds has shown relative improvement. Problems encountered in pediatric use of the cochlear implant are also discussed herein.

Child↗

PubMed1994

Evoked potentials from the auditory nerve following sinusoidal electrical stimulation of the cochlea: new possibilities for preoperative testing in cochlear-implant candidates?

To predict the possible benefit of a cochlear implant to a patient, the clinician requires a reliable objective method to monitor the presence of surviving fibres in the 8th nerve. The subjective promontory test and the evaluation of electrically evoked brainstem potentials are not adequate. An electrical stimulus artefact interferes badly with the potential recorded, but with electrical sinusoidal stimulation this stimulus artefact can be suppressed. The highly synchronous excitation of the auditory nerve fibres results in compound action potentials that can be recorded from the round window. The present animal experiments show that the method proposed is effective. Clinical tests are suggested.

Acoustic Stimulation↗

PubMed2004

Skin breakdown over cochlear implants: prevention of a magnet site complication.

OBJECTIVE: To determine the prevalence of inflammation of the skin around the magnet of cochlear implants. METHOD: A postal survey of 232 children implanted at The Hospital for Sick Children, Toronto, detailing the timing and severity of skin inflammation near the magnet. RESULTS: Sixty-three children (27%) had at least one episode of skin erythema at the magnet site. In most cases, this resolved after reducing magnet field strength. Nine children stopped wearing the device briefly, and five were treated with antibiotics. Skin ulceration occurred in two cases. No surgical treatment was required. Reactions tended to occur in younger children (2.8 vs 4.3 years; p = .002, Mann-Whitney rank sum test). CONCLUSIONS: Skin inflammation commonly occurs in children between magnets of the transmitter and receiver coils of a cochlear implant. If inflammation fails to resolve after loosening the magnet, use of the implant should be discontinued temporarily. Antibiotics should be prescribed for cellulitis to prevent an implant-threatening infection.

Adolescent↗

PubMed1990

[Electrophysiologic studies in patients with cochlear implants].

The insertion of reliable extracochlear single-canal cochlear implants in cophotic and subcophotic patients allows the electrical stimulation of the acoustic nerve for rehabilitation, as well as audiovestibular explorations that are no longer possible in the acoustic mode. The authors therefore aim at replacing all these examinations with their Electrical equivalent: --early evoked potentials (E-BERA), --medium-latency evoked potentials (E-MLR), --Event-related evoked potentials (E-P300), for which, to our knowledge, theses are the first recordings, --electrical stapedial reflex, --vestibular stimulations. The method, results and clinical and physiological applications of each method are given, as well as its prospects.

Acoustic Stimulation↗

PubMed1995

Cochlear implant performance in a deaf child of deaf parents: a case study.

Marie represents a unique case in the population of cochlear implant users, in that she is from a family of deaf individuals. Her auditory perceptual performance after 2 years of implant use is commensurate with that of other children of similar ages and durations of deafness. Although her speech production performance is also not atypical, the special circumstances in the home might cause additional delay. Studies have traditionally shown that deaf children of deaf adults exhibit superior ability in both social and academic domains when compared to deaf children of hearing parents. The cochlear implant provides yet another tool to add to the already-identified advantage extended this group by their family circumstance. It is unfortunate that these children for whom the device can offer enhanced abilities may be the very children that are denied access to it by the deaf community.

Auditory Perception↗

PubMed2005

[Quality of life in cochlear implanted patients].

Several articles show the audiologic benefits of cochlear implants, although it is still necessary to prove their impact on quality of life. In this study, 36 Med-El processor users were included. The Glasgow Benefit Inventory (GBI) was used to measure changes in quality of life, and another questionnaire was used to evaluate the communication abilities. Eighty-six percent of the patients answered our questionnaire. The quality of life improved significantly according to the specific questionnaire. The average total benefit obtained with the GBI was +41, and the average scores related to general, social and physics benefits were +57, +16, and +3, respectively. No significant difference was found between quality of life and other parameters like insertion depth of the array, etiology or duration of the deafness.

Adolescent↗

PubMed2001

Securing cochlear implants to the skull: two alternate methods.

In view of the various problems encountered with the traditional methods of securing cochlear implants--including dural tear and suture dissolution following infection--we devised two alternate methods of performing this procedure. We use a titanium mesh or a Gore-Tex patch secured with two 4-mm screws to fix the receiver to the skull. No patient who has undergone either of these procedures at our institution has experienced any of the complications that are associated with the older silk, nylon, and Dacron sutures. Moreover, our two alternate methods are less technically difficult and can be performed in a shorter period of time.

Cochlear Implantation↗

PubMed2005

[Cochlear implant in congenital malformations].

OBJECTIVE: The main objective is to evaluate the complications and problems encountered in a population with inner ear congenital malformation undergoing cochlear implantation. MATERIALS AND METHODS: The present study includes 33 patients with congenital inner ear malformation, from a total population of 346 cochlear implant patients, implanted from February 1993 to March 2004. Radiological evaluation and neurological exams were performed to all these patients in order to evaluate all the preoperative conditions. RESULTS: The most common cochlear anomalies we found were: cochlear hypoplasia, Incomplete partition and Common cavity (n=15). In 4 cases an enlarge aqueduct was also associated to the cochlear anomaly. We also found 6 cases with labyrinthine anomalies. The surgical procedure was performed in 23 cases, and in 18 of them we obtained an electrical stimulation of the neural elements. CONCLUSIONS: There are no differences between patients with Incomplete Partition of the cochlea and mild Cochlea hypoplasia, if compared with those with normal cochlea. Severe malformations as Common Cavity or severe hypoplasia may have a higher rate of surgical complications and the outcome cannot be predicted.

Adult↗

PubMed2005

Improved music perception with explicit pitch coding in cochlear implants.

Music perception and appraisal is very poor in cochlear implant (CI) subjects partly because (musical) pitch is inadequately transmitted by the current clinically used sound processors. A new sound processing scheme (F0mod) was designed to optimize pitch perception, and its performance for music and pitch perception was compared in four different experiments to that of the current clinically used sound processing scheme (ACE) in six Nucleus CI24 subjects. In the F0mod scheme, slowly varying channel envelopes are explicitly modulated sinusoidally at the fundamental frequency (F0) of the input signal, with 100% modulation depth and in phase across channels to maximize temporal envelope pitch cues. The results of the four experiments show that: (1) F0 discrimination of single-formant stimuli was not significantly different for the two schemes, (2) F0 discrimination of musical notes of five instruments was three times better with the F0mod scheme for F0 up to 250 Hz, (3) melody recognition of familiar Flemish songs (with all rhythm cues removed) was improved with the F0mod scheme, and (4) estimates of musical pitch intervals, obtained in a musically trained CI subject, matched more closely the presented intervals with the F0mod scheme. These results indicate that explicit F0 modulation of the channel envelopes improves music perception in CI subjects.

Adult↗

PubMed2005

Efficacy of a cochlear implant simultaneous analog stimulation strategy coupled with a monopolar electrode configuration.

OBJECTIVES: The present study was performed to evaluate the efficacy and clinical feasibility of using monopolar stimulation with the Clarion Simultaneous Analog Stimulation (SAS) strategy in patients with cochlear implants. METHODS: Speech recognition by 10 Clarion cochlear implant users was evaluated by means of 4 different speech processing strategy/electrode configuration combinations; ie, SAS and Continuous Interleaved Sampling (CIS) strategies were each used with monopolar (MP) and bipolar (BP) electrode configurations. The test measures included consonants, vowels, consonant-nucleus-consonant words, and Hearing in Noise Test sentences with a +10 dB signal-to-noise ratio. Additionally, subjective judgments of sound quality were obtained for each strategy/configuration combination. RESULTS: All subjects but 1 demonstrated open-set speech recognition with the SAS/MP combination. The group mean Hearing in Noise Test sentence score for the SAS/MP combination was 31.6% (range, 0% to 92%) correct, as compared to 25.0%, 46.7%, and 37.8% correct for the CIS/BP, CIS/MP, and SAS/BP combinations, respectively. Intersubject variability was high, and there were no significant differences in mean speech recognition scores or mean preference ratings among the 4 strategy/configuration combinations tested. Individually, the best speech recognition performance was with the subject's everyday strategy/configuration combination in 72% of the applicable cases. If the everyday strategy was excluded from the analysis, the subjects performed best with the SAS/MP combination in 37.5% of the remaining cases. CONCLUSIONS: The SAS processing strategy with an MP electrode configuration gave reasonable speech recognition in most subjects, even though subjects had minimal previous experience with this strategy/configuration combination. The SAS/MP combination might be particularly appropriate for patients for whom a full dynamic range of electrical hearing could not be achieved with a BP configuration.

Adult↗

PubMed1998

The production of English inflectional morphology, speech production and listening performance in children with cochlear implants.

OBJECTIVE: To compare how children who use either cochlear implants (CIs) or hearing aids (HAs) express English inflectional morphemes during conversation, i.e., with voice, with sign, or with both. A secondary objective was to investigate the relationship between morpheme use in pediatric CI users and their speech perception skills, length of experience with the device, and accuracy of phoneme production. DESIGN: Group 1 consisted of 25 children who used CIs, and Group 2 consisted of 13 children who used HAs. All children were prelingually deafened and all used simultaneous communication. A 12 minute spontaneous conversation was elicited, transcribed and coded. Between group comparisons were performed to evaluate differences in modality and number of morphemes used. Additionally, use of morpheme endings was related to length of CI experience, accuracy of phoneme production, and closed-set speech recognition performance. RESULTS: Children who had CI experience produced significantly more English inflected morphemes than children in the HA group. CI participants also expressed the inflected endings by using voice-only mode 91% of the time, whereas HA participants used voice-only mode 1% of the time. In the CI group, a strong relationship was found between number of morpheme endings used and speech recognition scores, length of CI experience and accuracy of phoneme production. The results of this study indicate that input from the CI facilitates children's ability to perceive and comprehend bound morphemes.

Adolescent↗

PubMed1997

Auditory event-related potentials in post- and prelingually deaf cochlear implant recipients.

The development of central auditory functions in cochlear implant (CI) patients was studied over six months of rehabilitation. Examinations were performed beginning with the first week after processor calibration, and in monthly follow-up sessions thereafter. The subjects were given a simple auditory perception task (detection of a 400 Hz and a 1450 Hz tone), as well as an oddball-paradigm (detection of one of the tones as a rare deviant). Auditory evoked potentials, reaction time and errors were recorded. Results from five patients, two postlingually deaf and three prelingually deaf CI recipients are shown. Generally, in the auditory evoked potentials of patients a shortening of N100 latency towards those of subjects with normal hearing was seen from month to month. However, in the prelingually deaf patients this effect was weaker and more variable over time. Three CI recipients showed a P300 component in the oddball-paradigm in correlation with their performance. Two prelingually deaf patients failed to show a P300 in the oddball-paradigm. For both components, the N100 and the P300 we found a larger spreading over the skull in the patients compared to a normal hearing person. The results show that from the very first days after initial processor fitting prelingually and postlingually deaf CI recipients may show cortical correlates of stimulus processing and discrimination. For some components of the auditory evoked potentials an initial temporal change but a maintained larger spreading over the skull was seen.

Cochlear Implantation↗

PubMed2004

Cochlear implantation in children with otitis media: second stage of a long-term prospective study.

OBJECTIVE: To present the findings of the second stage of an ongoing prospective study of the outcome of cochlear implantation in otitis media (OM)-prone and non-OM-prone children who were treated according to a structured protocol designed to control OM prior to implantation. PATIENTS AND METHODS: Of 60 children referred for cochlear implantation during the study period, 34 were classified as OM-prone (Group A) and 26 as non-OM-prone (group B). Group A patients were managed according to a structured protocol aimed at pre-implantation control of OM. A ventilating tube (with or without adenoidectomy) was inserted in the affected ear(s) of these children, if necessary more than once. Post-implantation follow-up ranged from 3 to 45 months (average 20 months). RESULTS: In the OM-prone group of children, the mean age at referral and at implantation was significantly lower and the mean interval between referral and implantation significantly higher than in the healthy group. During implantation, 21 children (19 from the OM-prone group A) had thick middle ear mucosa that had to be removed to allow identification of the round window niche. After implantation, 13 of the OM-prone children (38%) and 2 of the non-OM-prone children (7.6%) developed acute OM in the implanted ear. Five of these cases, all belonging to the OM-prone group, proved to be recurrent and therapeutically challenging, and 2 of them also developed acute mastoiditis. There were no other OM-related complications. CONCLUSIONS: Early referral led to early implantation, even in children susceptible to OM. The incidence of OM decreased after implantation, but was still significantly higher in the OM-prone group. On the basis of these results, we recommend the continuous use of a ventilating tube in OM-prone pediatric implantees until they outgrow their susceptibility to OM.

Child↗

PubMed1998

The identification of speech in noise by cochlear implant patients and normal-hearing listeners using 6-channel signal processors.

OBJECTIVE: To compare the recognition of vowels and sentences in noise by cochlear implant patients using a 6-channel, continuous interleaved sampling (CIS) processor and by normal-hearing subjects listening to speech processed in the manner of the implant processor and output as six amplitude-modulated sine waves. DESIGN: Subjects, 11 normal-hearing listeners and 7 cochlear implant patients, were presented natural vowels produced by men, women, and girls in /hVd/ context and sentences from the Hearing In Noise Test (HINT) lists at +15, +10, and +5 dB signal to noise ratio (SNR) for identification. Stimuli for the normal-hearing subjects were preprocessed through a simulation of a 6-channel implant processor and were output as the sum of sinusoids at the center frequencies of the analysis filters. RESULTS: For the multitalker vowels, four of the seven patients achieved scores within +/-1 standard deviation of the mean for normal-hearing listeners at +15 and +10 dB SNR. At the +5 dB SNR three patients achieved scores within +/-1 standard deviation of the mean for the normal-hearing listeners. For the HINT sentences, four of seven patients achieved scores within +/-1 standard deviation of the mean for the normal-hearing listeners at +15 dB and at +10 dB SNR and two achieved scores within that range at +5 dB SNR. CONCLUSION: Our results extend the range of stimulus conditions, from quiet to modest amounts of noise, in which the CIS strategy allows the best performing patients to extract most, if not all, of the information available to normal-hearing subjects listening to speech processed into six channels.

Adult↗