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PubMedDate not supplied

An international test battery for cochlear implant patients.

It is now clear that cochlear implants can provide useful hearing for profoundly deaf adults, and that multichannel devices give the brain more information than most single-channel devices. We are in a dilemma as to how to compare the many multichannel devices, because of the language barrier. Virtually no multichannel wearer is equally testable in two, let alone more languages. A test battery that abstracts beyond language is proposed, utilizing carefully constructed non-linguistic syllables and its development underway.

Cochlear Implants↗

PubMed1986

The UCSF/Storz multichannel cochlear implant: patient results.

Using the four channel cochlear implant system with a vocoder-based processor developed at UCSF over an extensive period of research, clinical trials of the UCSF/Storz device were initiated in February 1985, under the sponsorship of Storz Instrument Company. To date, 13 patients have been implanted with this device, nine of whom have been fitted with their external processor and transmitter and have received at least their initial postoperative evaluation. Patient results have been extremely promising, with eight of the nine patients obtaining some open-set auditory only speech understanding. Most patients have demonstrated improvement over time and all patients have attained an enhancement in lipreading ability with the use of the UCSF/Storz device.

Adult↗

PubMed1998

A tentative exploration of the character of pediatric cochlear implant critique.

Deaf communities have resisted pediatric cochlear implants in many western countries since the introduction of the technique in the late 1970's. In this struggle they have been supported by quite a few scientists from a diverse, albeit social scientific background. The arguments of the latter have been the source of much misapprehension. In this paper we will explore this misapprehension by structurally probing for implicit conceptualisations of benefit and legitimation procedures in the discourse of proponents and opponents alike.

Child↗

PubMed2005

A new minimal approach in cochlear implant surgery: the Colombian experience.

OBJECTIVES: To implement a minimal invasive approach in cochlear implant surgery for children and adults. In order to decrease surgical complications and morbidity with the surgery. SUBJECTS AND METHODS: During a 1-year period, 12 consecutive patients (5 female and 7 male; age range, 1.5 to 78 years; mean age, 14.5 years), who had cochlear implantation (1 Nucleus and 11 Clarion) through a new surgical approach, were prospectively evaluated. RESULTS: The surgical approach was accomplished in all the patients with no major complications. The mean surgical time was 3.2 hours and the mean time between surgery and process of programming was 2.7 weeks. CONCLUSION: The surgical trauma and postoperatory edema was decreased and allowed programming of the implant in a shorter period of time.

Adolescent↗

PubMed1997

Results from a pilot study using the nucleus CI24M/SP5 cochlear implant system.

OBJECTIVE: To conduct a pilot study in adults with the Nucleus CI24M/SP5 cochlear implant system. PATIENTS AND METHODS: Eight postlingually deafened adults who had received little or no benefit from conventional hearing aids, equipped with the Nucleus CI24M/SP5 cochlear implant system. RESULTS AND CONCLUSIONS: The results indicate that most of the subjects were able to perform well in speech recognition tests. The test performances appeared to be strongly affected by the duration of deafness. The speech processor's four user-selectable program memories have been extremely useful for the subjects to evaluate variations to the speech coding strategies in ordinary surroundings outside of the laboratory. The telemetry functions of the new implant provide a set of useful clinical and research tools for gathering greater insights into the in-situ operation of the implant.

Adult↗

PubMed1990

Acoustic cues for consonant identification by patients who use the Ineraid cochlear implant.

Ten patients who use the Ineraid cochlear implant were tested on a consonant identification task. The stimuli were 16 consonants in the "aCa" environment. The patients who scored greater than 60 percent correct were found to have high feature information scores for amplitude envelope features and for features requiring the detection of high-frequency energy. The patients who scored less than 60 percent correct exhibited lower scores for all features of the signal. The difference in performance between the two groups of patients may be due, at least in part, to differences in the detection or resolution of high-frequency components in the speech signal.

Adult↗

PubMed1995

Speech coding strategies of the digisonic fully digitized cochlear implant.

The Digisonic is a fully digitized cochlear implant. Because of its articulated array, its 15 electrodes can be inserted in the cochlea. Each electrode is recessed in a special silastic compartment of the array and has a very large stimulation area thanks to its large microrelief surface area. The small volume of its implanted receiver (flat cylinder diam 29 mm, 6.9 mm thick) allows it to be placed in 2-year-old children. The 128 point FFT of this device supply the patient with a full set of sound information between 64 and 7800 Hz. Electrode stimulation mode is sequential and stimulation rhythm is programmable. Electric crosstalk is decreased by the shape of the electrode array, and optionally by special programming of the neighboring electrodes. The speech therapist may select the width and peak value of each frequency band handled by each functional electrode. Because the versatility of this digitized emitter, many speech coding strategies can be easily programmed as a function of electrode responses or particular scientific considerations. A special version of this device, consisting of 10 separate electrodes, has been designed for use in patients with total obstruction of the cochlea. These insulated wires may be inserted one by one in the inner ear in 10 different recesses gently drilled in the bony cochlea. This device was placed in 46 patients between 1992 and 1994, including 8 young children (aged 2-9 years, mean 5 years) and 9 patients with total cochlear obstruction.

Child↗

PubMed1983

Preoperative hearing and evaluations for cochlear implant patients. A preliminary report using a Minimal Auditory Capabilities battery.

Two profoundly deaf patients were evaluated using the Minimal Auditory Capabilities (MAC) battery of speech discrimination tests. One patient was a multiple-channel cochlear implant patient (MC1) using a wearable speech-processor, the other a prospective cochlear implant patient using a hearing aid (HA). Results from the MAC battery showed that MC1 received significantly more auditory information via the speech-processor than was provided by the hearing aid to HA. These results indicated that the cochlear implant could be a suitable alternative for HA. However, the results indicated that HA gained some minimal benefit from the hearing aid and these results should be taken into consideration when deciding which ear should be implanted.

Cochlear Implants↗

PubMed1997

Speech perception by prelingually deaf children and postlingually deaf adults with cochlear implant.

We review recent data from the University of Iowa obtained from prelingually deaf children over 3 years using feature-extraction versions of the Nucleus cochlear implant, and from postlingually deaf adults using the compressed-analog Ineraid, a feature-extraction version of Nucleus, and a continuous interleaved sampling version of the Clarion cochlear implant. Both adults and children were followed over a 3-year period. Average results are shown where each patient is represented at each point in time. Results for the children show continued improvement over the 3-year period, with some children obtaining maximum scores possible on the easier closed-set tests. Substantial improvements in audiovisual enhancement were provided by the cochlear implant. Results from the adults show maximum gains within the first year of implant use, although some patients show continued improvements after 2 years of implant use. Adults who have been deaf for several years and who receive their implant when they are older tend not to perform as well as adults who have been deaf for only a few years or receive their implant when they are younger.

Adult↗

PubMed2002

Auditory late cortical response and speech recognition in Digisonic cochlear implant users.

OBJECTIVE: The purpose of the study was to test for differences in late electrically evoked auditory potentials between subjects exhibiting "good" versus "poor" speech recognition performances with their cochlear implants. METHODS: Late auditory evoked responses were measured in 30 subjects equipped with the Digisonic (MXM, Antibes, France) cochlear implant, 15 of whom had "good" speech recognition scores (i.e., more than 89% correct phoneme identification without lip reading). The 15 other subjects had poorer speech recognition scores (i.e., less than 85%). RESULTS: Differences in N1P2 amplitude, as well as P1, N1, and P2 latencies, and N1-P1 and N1-P2 latency intervals were tested. Wave P2 latency was found to be significantly different between the two groups (P =.016), being shorter in "good" than in "poor" performers. The strength of the statistical relationship between electrophysiological and speech recognition variables (r2 = 17%) was substantially smaller than that observed using electrically evoked auditory brainstem response (EABR) for the same implanted device (r2 = 49% for the EABR wave III-V latency interval). CONCLUSIONS: Some characteristics of late electrically evoked auditory potentials differ significantly among cochlear implant users depending on their speech recognition performance. However, the relationship between electrophysiological and speech recognition variables is more pronounced when early (brainstem) rather than late (cortical) evoked responses are considered.

Adult↗

PubMed1993

Prelingually deafened children's performance with the nucleus multichannel cochlear implant.

The speech perception abilities of 19 children with onset of deafness before age 3 years was examined after they received the Nucleus multichannel cochlear implant. The children were divided into two groups based on age at onset of deafness: children with congenital deafness (n = 8) and children with onset of deafness after birth but before age 3 (n = 11). There was no statistically significant difference between the scores of the two groups of subjects on 12 of the 13 speech perception tests administered. This finding suggests that children who are born deaf have the potential to derive the same benefit from cochlear implants as do children who have had some exposure to spoken language before the onset of their deafness. Examination of performance in terms of communication mode revealed that prelingually deafened children with implants who used oral communication obtained significantly higher scores on only 2 of the 13 speech perception measures than did children who used total communication. The data suggest that communication mode does not appear to account for large differences in speech perception performance among prelingually deafened children with multichannel cochlear implants.

Acoustic Stimulation↗

PubMed2004

Three-dimensional localization of cochlear implant electrodes using epipolar stereophotogrammetry.

Three-dimensional (3-D) localization of individual cochlear implant electrodes within the inner ear is of importance for modeling the electrical field of the cochlea, designing the electrode array, and programming the associated speech processor. A 3-D reconstruction method of cochlear implant electrodes is proposed to localize individual electrodes from two X-ray views in combination with the spiral computed tomography technique. By adapting epipolar geometry to the configuration of an X-ray imaging system, we estimate individual electrode locations in the least square sense without using a patient attachment required by an existing stereophotogrammetry technique. Furthermore, our method does not require any knowledge of the intrinsic and extrinsic parameters of the imaging system. The performance of our method is studied in numerical simulation and with patient data and is found to be sufficiently accurate for clinical use. The maximum root mean-square errors measured are 0.0445 and 0.214 mm for numerical simulation and patient data, respectively.

Cochlea↗

PubMed1998

Cochlear implantation under local anaesthesia, the Belfast experience.

The profoundly deaf, who gain little or no benefit from conventional hearing aids and meet various criteria are potential candidates for cochlear implantation. The last two decades have witnessed remarkable progress in this field, and it is now a routine clinical procedure. A few adult patients who are potential candidates for cochlear implantation have an unacceptably high risk for hypotensive general anaesthesia due to other systemic conditions. This group has been successfully implanted under local anaesthesia in our centre. The post-implantation progress of these patients was comparable to those carried out under hypotensive general anaesthesia. Data regarding patient selection criteria, examination, anaesthesia, surgery and the outcome are discussed. It was concluded that cochlear implantation under local anaesthesia is a safe and effective procedure for those patients who otherwise may be denied an implant.

Adult↗

PubMed1986

Vowel perception: experiments with a single-electrode cochlear implant.

We investigated vowel perception by 15 subjects using the single-electrode cochlear implant used at the House Ear Institute in Los Angeles. Subjects were postlingually deaf adults having histories of unsuccessful hearing aid use and a minimum of 6 to 12 months experience with the implant. Eleven American English vowels spoken by a male talker were tape recorded, digitized, analyzed, and controlled for the experiments. The stimuli were audio-recordings of both natural and loudness-matched vowels. Subjects rated the dissimilarity of both the naturally spoken and the loudness-matched vowels, and performed identification of the latter. Two normal-hearing subjects served as controls for the dissimilarity tasks. Multidimensional scaling, hierarchical clustering, and percent correct identification analyses were used to help determine the perceptual features used by the subjects in their judgments. Generally, the normal-hearing subjects took advantage of second formant (F2) frequency information. The cochlear-implant users relied primarily upon fundamental (F0) and first formant (F1) frequency information and demonstrated difficulty in vowel identification. No major differences were noted for the natural versus loudness-matched vowels. F2 information, requisite for accurate vowel recognition, did not correspond to any of the perceptual dimensions discerned in the results obtained from implant subjects.

Adult↗

PubMed2000

Chinese tonal language rehabilitation following cochlear implantation in children.

Cantonese language rehabilitation in 28 prelingually deaf children who underwent cochlear implantation was evaluated. All patients were implanted with multichannel devices and the operations went smoothly. They all had improved scores on audiological assessments and speech perception tests. The speech evaluation tests included the recognition of sounds, vowels, consonants and tone. Sentence recognition and story comprehension were both improved after training for 2 years. Cochlear implantation is a useful measure for the speech rehabilitation of prelingually profound deaf children when hearing aids are of no benefit. The multichannel implant device is of clinical significance in the rehabilitation of those patients using tonal language.

Child↗

PubMed2006

Auditory performance of cochlear implant children aged 2-5 years.

OBJECTIVE: To assess the categories of auditory performance in prelingual deaf children after implantation. STUDY DESIGN: Prospective study MATERIAL AND METHOD: The present study consisted of one boy and four girls aged between 2 and 5 years old at the time of implantation. All subjects had bilateral profound sensorineural hearing loss and received no substantial benefit from amplification. Three subjects were implanted with Med-El combi 40+ with CIS strategy and two subjects received multichanal monopolar Nucleus 24 cochlear implant with ACE strategy. After implantation, all subjects undertook a program ofhabilitation at the Speech and Hearing Clinic Ramathibodi Hospital. The Categories of Auditory Performance (CAP) score was determined at regular intervals prior to implantation, immediately at the initial mapping (0) and 3, 6, 12 and 18 months after the implantation. RESULTS: The results showed that before implantation, only three children showed awareness of environment sounds, CAP score level 1, and that immediately after mapping, all of the children demonstrated awareness of the environmental sounds. Moreover, two of these children showed awareness of speech sounds, CAP score level 2. The CAP scores were gradually increased over a 12-month period. At the 12-month assessment interval, four children could discriminate two speech sounds, CAP score level 4 and one child understood phrases without lip reading, CAP score level 5. 18 months after of implantation, the CAP score for four children increased to level 5. One child understood conversation without lip reading with a familiar talker, CAP score level 6. Furthermore, children with congenital hearing loss who underwent implantation at a younger age received more benefit from the implantation. CONCLUSION: The CAP score was found to be a useful and sensitive tool to evaluate the outcome of auditory receptive abilities in young congenital deaf children who underwent cochlear implantation. The accessible outcome measurement will provide information for parents and professionals to obtain a hierarchical scale on which the children's auditory ability with other more formal measures may be inappropriate.

Child, Preschool↗

PubMed2000

[Speech discrimination in noise for patients with cochlear implants].

The aim of the study was to evaluate the speech discrimination ability of postlingually deaf adults implanted with the Combi 40 cochlear implant in noise and to compare the results with the speech discrimination ability of patients provided with hearing aids. The 12-month postoperative hearing performance of 12 consecutive patients was tested using a sentence discrimination test in quiet and noise. The results of the present study demonstrate that all patients obtained substantial benefit from their implants even in situations coupled with noise. The speech understanding of cochlea-implanted patients appears to be better than that of patients provided with hearing aids. Very high scores (mean, 40.2%) were achieved at a signal-noise ratio of 15 dB.

Adult↗

PubMed2003

The effects of frequency response on speech perception for cochlear implant users.

The aim of this study was to investigate the effects on speech perception of manipulating filter gains in a cochlear implant speech processor. Five implantees, who use the CI22 implant and Spectra processor manufactured by Cochlear Ltd, participated. Four experimental maps were created that were identical to their clinical map except for the profile of gains across the filters. Experimental gain profiles had rising or falling gains across the frequency range, or emphasized or de-emphasized the middle frequencies, relative to the clinical map. Perception of CNC (consonant-vowel-consonant) words at 70 dB SPL was significantly better with the clinical map than with all experimental maps, whereas at the lower level (60 dB SPL) there was minimal difference between the maps, with the low-frequency emphasis map giving significantly better scores than the high-frequency emphasis map. Perception of sentences at 70 dB SPL with a signal-to-noise ratio of +10 dB was better with the high-frequency emphasis map than with the low-frequency emphasis map. None of these best-conditions, however, were statistically better than the clinical map. The results highlighted the importance of signal audibility for speech perception with cochlear implants.

Adult↗