SEARCH · PubMed Health
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.
The authors analyse the results of examination of 225 patients for defining indications to cochlear implantation, give grounds for a thorough examination with allied specialists, outline the indications in 93 patients and predict rehabilitation efficacy after cochlear implantation in different groups of patients.
This article examined a database of Australian daily newspapers on the terms cochlear implant and deaf children to investigate how journalists and columnists report competing models of deafness: as either "medical" (deafness is a condition to be cured) or "sociocultural" (deafness provides a way of life to be lived). The results from the cochlear implant search favored a medical model, but the results from the deaf children search were more balanced, with a slight preponderance of articles favoring the sociocultural model. A number of representative quotes from articles in each model are provided and discussion entered into as to the possible effects of the articles on public reactions to deafness and especially hearing parental responses to the birth of a deaf child and the life choices that this event presents them.
This paper describes the listening habits and musical enjoyment of postlingually deafened adults who use cochlear implants. Sixty-five implant recipients (35 females, 30 males) participated in a survey containing questions about musical background, prior involvement in music, and audiologic success with the implant in various listening circumstances. Responses were correlated with measures of cognition and speech recognition. Sixty-seven implant recipients completed daily diaries (7 consecutive days) in which they reported hours spent in specific music activities. Results indicate a wide range of success with music. In general, people enjoy music less postimplantation than prior to hearing loss. Musical enjoyment is influenced by the listening environment (e.g., a quiet room) and features of the music.
This report describes studies on electrode selection of the speech processor of a 22 channel cochlear implant device for 14 Japanese consonants, and on consonant recognition of 23 cochlear implant patients as they relate to electrode selection. The means of electrode selection was studied using a special device capable of detecting code signals delivered from the speech processor for electrode selection. Young male voices consisting of/a/+consonant+/a/ were presented as sound stimuli, and the electrode numbers selected were recorded for each consonant. The recorded numbers were grossly divided into two groups; a higher frequency range of about 500Hz to 4,000Hz and a lower range of 0Hz to about 1,100Hz. They showed characteristic patterns for each consonant, and these electrode number patterns were compared with patterns estimated from a sonogram. Although there were some differences between these two patterns in unvoiced stop consonants, they were roughly parallel to each other in other consonants. The information transfer ratio was calculated based on confusion matrices obtained from test results on 23 patients for 14 consonants. The ratio was high in voicing and semivowels, whereas it was relatively lower in plosives. This seems reasonable on the basis of patterns of electrode number transitions. Nasals and fricatives, however, showed lower information transfer ratios despite adequate electrode selection, and this may due to poorer information transition or the high frequency components of these consonants.
Fifteen profoundly deaf patients under the age of 18 years have received a 3M/House cochlear implant. The surgical procedure employed is essentially the same as that used in adults with a few modifications to accommodate for the smaller dimensions of the mastoid process and the thinness of the scalp and temporal squama. Pediatric subjects receive timing and intensity information at similar thresholds as adults implanted with this device which contributes to improvement in speech production to various degrees. All subject groups demonstrated significant language delays as a result of their profound hearing losses. Postimplantation, more growth was seen in receptive than in expressive language skills. However, the growth observed did not exceed that expected in profoundly deaf children as reported in the literature. Language growth as a result of the cochlear implant alone is yet to be documented in our patients.
In a previous study, the authors described a technique for recording ipsilateral EABRs using the DIGISONIC MXM cochlear implant (Gallégo et al, Acta Otolaryngol (Stockh) 1996; 116: 228-33) and showed that the EABR input/output functions were very similar across electrodes. In the present study a test of electrode functioning based on the recording of surface potentials is presented. Then, for each electrode the relationship between EABR thresholds and hearing thresholds was determined. Lastly, the relationship between EABR parameters and patients' performances was studied. The results show that the functioning of each implanted electrode can be assessed quickly, accurately and objectively. Furthermore it is demonstrated that a strong correlation between EABR and hearing threshold can be obtained using an automatic EABR wave detection technique. Finally it is shown that EABR inter-peak intervals are related to patient performance. These results are of the utmost importance for cochlear implant setting in children as they indicate a method of objective assessment of the functioning of each electrode and of the corresponding hearing threshold.
AIM: To evaluate the effects of different signal-to-noise ratios on speech recognition obtained by the use of cochlear implant (CI); to compare the speech recognition in noise with different types of multichannel cochlear implants (CIs) and to evaluate the degree of difficulty for speech understanding in noise in daily life situations. STUDY DESIGN: Cohort transversal. MATERIAL AND METHOD: Forty adults with post-lingual hearing loss implanted with Nucleus 22, Nucleus 24, Combi 40, Combi 40+ and Clarion. We evaluated the recognition for CPA sentences in quiet and in S/N +15, +10 and +5 dB. We also applied the Social Hearing Handicap Index (SHHI) questionnaire for self-assessment in daily life. RESULTS AND CONCLUSION: All the implanted adults presented a significant reduction in the scores for sentences recognition as the S/N decreased. The medians' curve for sentence recognition reached 50% in the signal-to-noise ratio of +10 dB. There was no statistically significant difference in sentences' recognition scores and difficulty scores obtained with the SHHI, for all types of implants. The difficulties of implanted adults were rare in quiet and occasional in noisy situations according to SHHI questionnaire.
The large vestibular aqueduct syndrome (LVAS) is commonly found when presurgical computed tomography is performed in advance of cochlear implantation. We present data on two patients with LVAS, in whom computed tomography (CT) and magnetic resonance imaging (MRI) was performed. Cochlear implantation when these malformations are present may be complicated by an intraoperative gusher, but it appears to be safe and produces a favorable outcome.
OBJECTIVE: The primary purpose of this study was to evaluate the diagnostic accuracy of averaged electrode voltages (AEVs) for identifying malfunctioning electrodes in cochlear implant users. DESIGN: AEVs were measured using common ground (N = 33 ears) and monopolar stimulation modes (N = 40 ears) in adult subjects implanted with the Nucleus 24M or Nucleus 24R(CS) cochlear implant. AEV measures were then compared with common ground electrode impedance measures as well as to subjective judgments of electrode sound quality to determine the sensitivity and specificity of AEVs. RESULTS: Results showed excellent specificity for both modes of AEV testing: 97.9% for common ground and 99.8% for monopolar. Sensitivity for common ground AEV testing was 91.7%; however the sensitivity of monopolar AEVs was very poor, at 7.7%. Monopolar AEVs accurately identified open circuits but missed all short circuits. These results are consistent with the sensitivity of impedance measures made with each of the two stimulation modes. CONCLUSIONS: Common ground AEVs are more reliable than monopolar AEVs for identifying malfunctioning electrodes.
The use of cochlear implants in born-deaf infants addresses the issues of disability, proxy consent, and potential ethnocide of the Deaf culture. The ethical issues explored in this paper are: 1) the disability versus trait argument of deafness, 2) parents versus Deaf community in proxy consent, 3) justification for surgical intervention in a non-life threatening condition, and 4) justification for ethnocide. Decisions for non-competent individuals should be made to assure the child of an open future, with rights that need to be protected now, so that the child can exercise them later as an adult. Cochlear implants provide the potential of an open future and are morally justified on that basis.
INTRODUCTION: The computer-based ENG system's analytical routine refinements are available only in research laboratories. The computer-based system contains a stimulator for saccadic eye-movement and an air caloric stimulator interconnected to the registration program and analysis software. Several authors have reported the preoperative and postoperative vestibular functions in cochlear implant patients. The safe examination of the operated ear and comparison of the preoperative and postoperative average slow phase velocities of the caloric nystagmus is possible using the air caloric computer system. METHODS: The authors have used a computer-based ENG system with caloric air stimulation, which is very useful for examination of the operated ear. The vestibular system of patients with total deafness was examined before and after the cochlear implantation. The results of 60 vestibular examinations of 64 patients are reported. RESULTS: The vestibular function in the operated ear was found unchanged in 20 patients. In 14 patients the vestibular function was worse. In 16 patients the postoperative vestibular responsiveness improved. The detailed data analysis of 10 patients in whom preoperative and postoperative vestibular examination was similar was performed by the authors. The preoperative and postoperative average slow phase velocity values and the relative canal paresis was observed. The values demonstrated that the caloric responsiveness of the operated ear improved in few cases. CONCLUSIONS: The computer-based air caloric system is a useful and safe method in evaluation of the vestibular system changes after ear surgery. The reason of the improvement of vestibular responsiveness is not clear. The results need further investigation to solve the problem of vestibular responsiveness improvement after cochlear implantation.
To investigate the activation of the auditory cortex by fMRI, three deaf subjects users of the Ineraid cochlear implant participated in our study. Possible interference between fMRI acquisition and the implanted electrodes was controlled and safe experimental conditions were obtained. For each subject, electrical stimuli were applied on different intracochlear electrodes, in monopolar mode. Stimulation of each electrode was actually producing auditory sensations of different pitches, as demonstrated by psychophysical pitch-ranking measurements in the same subjects. Because deaf subjects did not hear scanner noise, the data were collected in 'silent background' conditions, i.e. as a result of pure auditory sensations. Functional maps showed activation of the primary auditory cortex, predominantly in the left hemisphere. Stimulation of each different intracochlear electrode revealed different clusters of activation. After cluster grouping, at least three regions have been identified in the auditory cortex of each subject, and comparisons with previous architectonic and functional studies are proposed. However, a tonotopic organization could not be clearly identified within each region. These arguments, obtained without interference with unwanted scanner noise, plead in favor of a functional subdivision of the primary auditory cortex into multiple cortical regions in cochlear implant users.
A series of experiments with a thinfilm multichannel cochlear implant is presented. A number of surgical difficulties at implantation on temporal bones were experienced. In vitro measurements of the electrode's technical properties revealed 1) large variations in the impedance, and 2) good separation between channels. From a theoretical point of view this complicated type of electrode is interesting, but a number of modifications are necessary before it may be used for implantation in man.
In order to determine the criteria for patient selection and the preoperative prognostic factors for hearing recovery after cochlear implants in young totally dead children, the results of hearing rehabilitation were studied in 15 children who had undergone cochlear implantation at from 2 to 9 years of age. The choice of implant is determined by the permeability of the cochlear duct. A multi-system should be used, except when the cochlea is totally ossified. The reliability and efficacy of mono and multi system implants make it possible to offer a solution to the urgent therapeutic problems posed by total deafness in the young child.
In principle, an acoustic contact with the environment can be achieved in all cochlear implant patients. However, the results vary greatly in our 37 surgically treated cases. On average, our patients can (1) perceive background noises, (2) recognize different human voices, (3) differentiate differences in pitch, (4) improve lip reading and (5) improve pronunciation appreciably. (6) In addition, closed speech is largely understood. Apart from these average values, we were able to observe a beginning of open speech in 20% of the cases (simple sentences from everyday speech). A precise statistical documentation is presented with an evaluation table we have elaborated. The results of comparison between the pre-lingual and post-lingual patients are analyzed statistically. The special significance of subjective evaluation of the advantages of cochlear implant on the part of the patients is pointed out. The lower age limit in our patient material is 10 years.
This case study will review the performance of a 7-year-old female who was implanted at the age of 3 years 9 months with a Nucleus 22 channel device. This child was deafened from pneumococcal meningis at the age of 8 months and was placed in an early intervention program which uses simultaneous communication (i.e. speech with sign language). The teaching staff of this particular educational setting has collaborated closely with the Cochlear Implant Center at Manhattan Eye, Ear and Throat Hospital and the team's teacher of the deaf. The child utilized the implant on a daily basis for a period of 2 years 10 months. Performance on a variety of auditory perceptual tests were obtained at 1 year and two year intervals. After almost 3 years of implant use, the child suffered an internal receiver failure. The Nucleus device was explanted and the child was implanted with a Clarion Cochlear Implant System. Performance on a similar set of auditory perceptual tests obtained after 3 and 6 months use indicated better performance with the Clarion device. In addition to the scores on the individual tests, a comparison questionnaire was used to obtain impressions from the parents and the school personnel. Results should be reviewed with caution since this study investigates the responses of a single child who uses each of these two different implants and cannot be generalized.
The removal of a functioning cochlear implant in order to upgrade to a more advanced device is a critical issue to many otologists, since we currently have no means to predict the results preoperatively. This paper reports on two patients who successfully upgraded from a single-channel to a multichannel implant. The new implants outperformed the original devices in both the live-voice test and the videotaped test. The patients stated that the hearing quality afforded by the multichannel implant was much better than that provided by the original implant.
Speech understanding with compressed analogue (CA) and continuous interleaved sampling (CIS) coding strategies for cochlear implants was compared in quiet and in noise at signal-to-noise ratios (SNRs) of 15, 10 and 5 dB. The speech recognition of three experienced users of the Ineraid cochlear implant (CA coding strategy) was assessed using a set of sentence, vowel and consonant tests. Three weeks after the fitting of a CIS processor, the tests were repeated with the new device. Speech recognition scores for the sentence and consonant tests tended to be higher with the CIS processor in no or little noise, but lower in the test situations with less favourable SNRs, when compared to the CA processor (average score differences for the consonant test: +7.8% correct at 15 dB SNR; -6.8% correct at 5 dB SNR; p = 0.05). Results for the vowel test were slightly lower on average for the CIS processing strategy at all SNRs. A possible explanation for the differences in performance between CIS and CA in the consonant and sentence tests at different SNRs is the generally higher free-field threshold associated with the CA coding strategy, which may act as a single-channel noise suppression.