First field trials with a portable CIS processor for the Ineraid multichannel cochlear implant

The continuous interleaved sampling (CIS) strategy is a promising sound processing strategy for multichannel cochlear implants which provides immediate improvements in speech recognition when tested on Ineraid users: patients with only a few hours of experience (in laboratory testing) with the CIS strategy score better than with the Ineraid prosthesis they used since they, were implanted. The goal of this study was to evaluate the benefits that can be gained by the use of the new strategy in every day life. Two patients, implanted with the Ineraid multichannel cochlear implant, were equipped with a portable numerical processor programmed to implement a high rate CIS strategy. Their speech recognition was evaluated periodically with consonant and vowel identification tests for more than 6 months of use. Tests were also made with the Ineraid processor during the same experimental sessions and patients were regularly interviewed about their experience. Performance with the portable CIS processor was superior or equal to that obtained previously in the laboratory with the same strategy. Both patients achieved the best scores in 6 years of cochlear implant use. Qualitative reports from the patients suggest that the CIS strategy can improve "hearing" performance of cochlear implant users in many important situations of every day life. Altogether, these results hold great promises for all users of the Ineraid multichannel cochlear implant.     

Multichannel cochlear implantation with inner ear malformation: case report of performance and management

A small percentage of children who have received the Nucleus multichannel cochlear implant have cochlear malformations of the inner ear and consequent partial electrode insertions. This case describes one child with a cochlear "common cavity" who received an implant at a young age. The case has been further complicated by a gradual malfunction of the electrode array, although the device has not failed completely. Despite the increase in the number of nonfunctional electrodes over time, the subject has continued to improve in auditory, speech production, and language development over a 30-month period. Methods are discussed for clinical monitoring of both performance and the stability of electrodes over time. The circumstances of this case reinforce the importance of postimplant collaboration with families and school staff and highlight the need for objective measures to evaluate both longitudinal changes in performance and device integrity.     

Cochlear implantation of children with minimal open-set speech recognition skills

OBJECTIVE: The purpose of this study was to evaluate the postoperative performance of 12 children who demonstrated some open-set speech recognition skills before receiving a Nucleus multichannel cochlear implant with a view toward expanding the selection criteria for cochlear implant candidacy to include children who derive minimal benefit from amplification. DESIGN: Pre- and postoperative performance of two groups of children were compared. Group 1 consisted of 12 children who demonstrated some open-set speech recognition skills before receiving a Nucleus multichannel cochlear implant (Borderline group). Group 2 consisted of 12 children who demonstrated no open-set speech recognition skills before implantation with a Nucleus device (Traditional group). In all children, candidacy was determined based on preimplant binaural aided performance. For most subjects, the poorer ear was selected for implantation. Mean pre- and postoperative speech recognition scores of the Borderline subjects were compared to determine the benefit provided by their cochlear implants. Secondly, matched-pair analyses were used to compare the mean speech recognition scores obtained by the Borderline and Traditional subjects. RESULTS: The scores of the Borderline group improved significantly on five of six speech recognition measures when 6 mo postoperative scores obtained with the implant were compared with preoperative test scores obtained with hearing aids. By the 12 mo postoperative interval, the scores of the Borderline group had improved significantly (p < 0.05) on all six measures. In contrast, scores obtained by the Traditional group had improved significantly on three of six measures at both the 6 and 12 mo postoperative intervals. Comparison of postoperative test scores revealed that the Borderline group scored significantly higher than the Traditional group on three of six measures at the 6 mo test interval and on six of six measures at the 12 mo test interval (p < 0.05). CONCLUSIONS: The findings of this study indicate that both groups derive significant benefit from their cochlear implants. Although the mean preoperative audiograms for the implanted ears did not differ significantly for the two groups of subjects, members of the Borderline group exhibited significantly better speech recognition skills than the Traditional group during the first year after implantation. These findings suggest that the increased auditory experience of the Borderline subjects positively influenced their performance with a cochlear implant. The authors advocate that the selection criteria used to determine pediatric cochlear implant candidacy be broadened to include consideration of children who demonstrate minimal open-set speech recognition skills.     

Production constraints on utterance-final consonant characteristics in babbling

In order to evaluate hypotheses regarding production constraints on final consonants in babbling, 721 utterance-final consonants produced by 6 infants in consonant-vowel-consonant (CVC) syllables were examined and compared with the preceding consonant in the CVC. Consistent with earlier studies, major patterns were observed for each of the three main consonantal properties--place and manner of articulation and voicing. These patterns included a strong tendency for final consonants to repeat the place of articulation of nonfinal consonants and a tendency for relatively more fricative, nasal and voiceless consonants to occur in final position than in nonfinal position. The high frequency with which final consonants shared place of articulation with the preceding consonant was considered to reflect 'frame dominance' or the tendency of a relatively constant mandibular cycle (the frame) to determine the structure of utterances with very little contribution from other active articulators. The manner and voicing effects were attributed to an overall terminal energy decrease in the vocal production system.     

Aided speech recognition abilities of adults with a severe or severe-to-profound hearing loss

Adults with severe or severe-to-profound hearing losses constitute between 11% and 13.5% of the hearing-impaired population. A detailed investigation of the speech recognition of adults with severe (n = 20) or severe-to-profound (n = 14) hearing loss was conducted at The University of Melbourne. Each participant took part in a series of speech recognition tasks while wearing his or her currently fitted hearing aid(s). The assessments included closed-set tests of consonant recognition and vowel recognition, combined with open-set tests of monosyllabic word recognition and sentence recognition. Sentences were presented in quiet and in noise at +10 dB SNR to replicate an environment more typical of everyday listening conditions. Although the results demonstrated wide variability in performance, some general trends were observed. As expected vowels were generally well perceived compared with consonants. Monosyllabic word recognition scores for both the adults with a severe hearing impairment (M = 67.2%) and the adults with a severe-to-profound hearing impairment (M = 38.6%) could be predicted from the segmental tests, with an allowance for lexical effects. Scores for sentences presented in quiet showed additional linguistic effects and a significant decrease in performance with the addition of background noise (from 82.9% to 74.1% for adults with a severe hearing loss and from 55.8% to 34.2% for adults with a severe-to-profound hearing loss). Comparisons were made between the participants and a group of adults using a multiple-channel cochlear implant. This comparison indicated that some adults with a severe or severe-to-profound hearing loss may benefit from the use of a cochlear implant. The results of this study support the contention that cochlear implant candidacy should not rely solely on audiometric thresholds.     

Cognitive and affective functioning in Parkinson''s disease patients with lateralized motor signs

OBJECTIVE: This study aimed to compare recordings of the electrically evoked whole nerve action potential (EAP) made using the reverse telemetry system of the Nucleus CI24M device with those recorded from individuals who use the Ineraid cochlear implant system. STUDY DESIGN: Data were collected in a prospective fashion from Nucleus CI24M cochlear implant users and compared with retrospective data collected from patients who use the Ineraid device. SETTING: All data were collected at the Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics. PATIENTS: Data are reported from 8 patients who use the Nucleus CI24M cochlear implant and 20 patients who use the Ineraid cochlear implant system. INTERVENTIONS: The interventions described in this study were diagnostic in nature. MAIN OUTCOME MEASURES: EAP growth and refractory recovery data are reported. EAP thresholds recorded from patients who use the Nucleus CI24M device also are compared with behavioral thresholds for the stimulus used to evoke the EAP as well as the stimulation levels needed to program the speech processor. RESULTS: EAP morphology, growth, and refractory recovery functions recorded using the Nucleus CI24M reverse telemetry system compared favorably with similar measures recorded from Ineraid cochlear implant users. CONCLUSIONS: Reasonable EAP responses can be recorded using the Nucleus CI24M device. More data are needed to determine whether the information about neural responsiveness available with this device will be clinically useful.     

Improvements in speech perception by children with profound prelingual hearing loss: effects of device, communication mode, and chronological age

The present investigation expanded on an earlier study by Miyamoto, Osberger, Todd, Robbins, Karasek, et al. (1994) who compared the speech perception skills of two groups of children with profound prelingual hearing loss. The first group had received the Nucleus multichannel cochlear implant and was tested longitudinally. The second group, who were not implanted and used conventional hearing aids, was tested at a single point in time. In the present study, speech perception scores were examined over time for both groups of children as a function of communication mode of the child. Separate linear regressions of speech perception scores as a function of age were computed to estimate the rate of improvement in speech perception abilities that might be expected due to maturation for the hearing aid users (n=58) within each communication mode. The resulting regression lines were used to compare the estimated rate of speech perception growth for each hearing aid group to the observed gains in speech perception made by the children with multichannel cochlear implants. A large number of children using cochlear implants (n=74) were tested over a long period of implant use (m=3.5 years) that ranged from zero to 8.5 years. In general, speech perception scores for the children using cochlear implants were higher than those predicted for a group of children with 101-110 dB HL of hearing loss using hearing aids, and they approached the scores predicted for a group of children with 90-100 dB HL of hearing loss using hearing aids.     

Speech-evoked cognitive P300 potentials in cochlear implant recipients

The cognitive P300 evoked potential was elicited by speech stimuli in successful cochlear implant recipients, and the resulting P300 morphology was remarkably similar to that of normal-hearing individuals. The P300 was elicited by the synthesized speech pair/da/and/di/ presented using an oddball paradigm to nine "good" Nucleus cochlear implant users and nine age-matched normal-hearing subjects (34-81 yr old). There were no significant differences in P300 amplitude and latency between the two groups. Moreover, the N1 and P2 potentials occurred at similar latencies in the two groups, although the N1 amplitude was significantly smaller in the cochlear implant users. The P300 was absent in one "poor" cochlear implant user. The results suggest that the P300 may serve as a useful tool for evaluating the cognitive aspects of auditory processing in cochlear implant recipients, and that it may aid in assessing the success of cochlear implantation.     

Cochlear implant performance after reimplantation: a multicenter study

OBJECTIVE: This study compares auditory performance between original and replacement cochlear implants. STUDY DESIGN AND SETTING: Data from 18 U.S. cochlear implant programs were obtained by retrospective chart review. Patients received and returned subjective questionnaires. PATIENTS: Twenty-eight adults with once-functioning Nucleus 22 cochlear implants that failed received replacement Nucleus 22 cochlear implants in the same ears. MAIN OUTCOME MEASURES: Objective measures included sentence (CID Everyday Sentences or Iowa Sentences) and monosyllabic word (NU-6 Words or CNC Words) speech discrimination scores. Patients also rated and compared performance using subjective scales. RESULTS: Thirty-seven percent of patients had significantly higher sentence or word scores with their replacement cochlear implants than with their original implants, 26% had no significant change, and 37% had significantly poorer scores. Subjectively, 57% of patients reported that the performance of their replacement device was better or the same and 43% reported that it was poorer. There was no correlation between performance with the replacement cochlear implant and cause of the original device failure, duration of original device use before failure, surgical complications with either implantation, changes in electrode insertion depths, or preoperative variables, such as age, etiology, or duration of deafness. CONCLUSIONS: Speech recognition ability with a replacement cochlear implant may significantly increase or decrease from that with the original implant. Experienced cochlear implant patients facing reimplantation must be counseled regarding the possibility of differences in sound quality and speech recognition performance with their replacement device.     

Electrode discrimination and speech recognition in postlingually deafened adult cochlear implant subjects

This study investigated the relationship between electrode discrimination and speech recognition in 11 postlingually deafened adult cochlear implant subjects who were implanted with the Nucleus/Cochlear Corporation multichannel device. The discriminability of each electrode included in a subject's clinical map was measured using adaptive and fixed-level discrimination tasks. Considerable variability in electrode discriminability was observed across subjects. Two subjects could discriminate all electrodes, and discrimination performance by the remaining nine subjects varied from near perfect to very poor. In these nine subjects, the results obtained from the discrimination tasks were used to create a map that contained only discriminable electrodes, and subjects' performance on speech recognition tasks using this experimental map was measured. Four different speech recognition tests were administered: a nine-choice closed-set medial vowel recognition task, a 14-choice closed-set medial consonant recognition task, the NU6 Monosyllabic Words Test [T. W. Tillman and T. Carhart, Tech. Rep. No. SAM-TR-66-55, USAF School of Aerospace Medicine, Brooks Air Force Base, Texas (1966)] scored for both words and phonemes correct, and the Central Institute for the Deaf (CID) Everyday Sentences test [H. Davis and S. R. Silverman, Hearing and Deafness (Holt, Rinehart, and Winston, New York, 1978)]. Seven of the nine subjects tested with the experimental map showed significant improvement on at least one speech recognition measure, even though the experimental map contained fewer electrodes than the original map. Three subjects' scores improved significantly on the CID Everyday Sentences test, three subjects' scores improved significantly on the NU6 Monosyllabic Words test, and five subjects' scores improved significantly on the NU6 Monosyllabic Words test scored for phonemes correct. None of the subjects' scores improved significantly on either the vowel or consonant tests. No significant correlation was observed between electrode discrimination ability and speech recognition scores or between electrode discrimination ability and improvement in speech recognition scores when programmed with the experimental map. The results of this study suggest that electrode discrimination tasks may be used to improve speech recognition of some cochlear implant subjects, and that each electrode site does not necessarily provide perceptually distinct information.     

Production and perception of final consonant voicing in speech produced by inexperienced signers during simultaneous communication

Simultaneous communications combines both spoken and manual modes to produce each word of an utterance. This study investigated the potential influence of alterations in the temporal structure of speech produced by inexperienced signers during simultaneous communication on the perception of final consonant voicing. Inexperienced signers recorded words that differed only in the voicing characteristic of the final consonant under two conditions: (1) speech alone and (2) simultaneous communication. The words were subsequently digitally edited to remove the final consonant and played to 20 listeners who, in a forced-choice paradigm, circled the word they thought they heard. Results indicated that accurate perception of final consonant voicing was not impaired by changes in the temporal structure of speech that accompanied the inexperienced signers' simultaneous communication.     

Labeling of musical interval size by cochlear implant patients and normally hearing subjects

OBJECTIVE: To compare the performance of cochlear implant patients and normal-hearing subjects on a musical interval labeling task, and to determine whether information regarding musical interval size is available to cochlear implant patients under realistic everyday listening conditions. DESIGN: Two Nucleus cochlear implant patients listened to musical intervals that consisted of systematic variations of electric pulse rate on single bipolar intracochlear electrode pairs, whereas normal-hearing listeners were presented with the acoustical analog of these stimuli. Subjects labeled the intonation quality of the stimulus intervals ("flat," "sharp," or "in tune"), relative to their memory for specific intervals abstracted from familiar melodies. The cochlear implant patients, in addition, performed this task with realistic acoustical musical stimuli. RESULTS: The interval labeling behavior of cochlear implant subjects, at low pulse rates, was similar to that of normal-hearing subjects. Furthermore, pitch interval information does not appear to be available to cochlear implant subjects when they are listening to acoustical stimuli via their speech processors. CONCLUSIONS: Temporal information appears to be sufficient for the perception of musical pitch. Encoding strategies that are highly successful in restoring speech understanding do not necessarily provide information regarding melodic pitch interval size.     

Integrin associated proteins

The Clarion cochlear implant was developed in the USA and received FDA approval in August 1996. It consists of an implantable cochlear stimulator (ICS), speech processor with headpiece, and in addition, a clinician's programming system and portable cochlear implant tester. One of the features of the device is its stimulation-coding process for which two methods of continuous interleaved sampling (CIS) and compressed analogue (CA) are applicable. Regardless of which is used, stimulation can be provided over 8 channels. The device was used in 2 cases. Both patients were operated on in October 1996, and 16 electrodes in 8 pairs were mounted in the cochlea. Mapping, performed 3 weeks after the operation, showed good speech perception in both patients with only a cochlear implant in the "open-set" status. CIS was used as the stimulation-coding method. CA has yet to be applied.     

Discrimination and identification of voicing and place contrasts in aphasic patients.

Examined the relationship between ability to discriminate and identify 3 synthetic speech continua representing vowel, voicing, and place contrasts and level of auditory language comprehension in 19 41–68 yr old male aphasics and 8 42–65 yr old non-brain-damaged controls. Aphasics were assigned to a good or a moderate comprehension group (GCG and MCG) on the basis of their auditory language comprehension scores. Both groups of aphasics performed the same as controls on the vowel contrasts. In comparison with controls, aphasics in the MCG had difficulty perceiving voicing and place contrasts, whereas aphasics in the GCG had difficulty perceiving place contrasts only. The MCG had more difficulty than the other 2 groups in discriminating stimuli at the inner boundary of each phoneme category. They were also most impaired in identifying the endpoints of the place and voicing continua. Place contrasts were more difficult to identify than voicing contrasts for both aphasic groups. In terms of the relationship between discrimination and identification, the majority of Ss either discriminated and identified the stimuli at equal levels of performance, or discriminated but did not identify the stimuli. Results indicate that auditory language comprehension predicts, to some extent, perception of voicing and place contrasts. (French abstract) (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cochlear implants in children: an analysis of use over a three-year period

OBJECTIVE: This study aimed to determine whether children continue to wear their cochlear implant systems 1 and 3 years after implantation. STUDY DESIGN: The design was a prospective study based on the analysis of forced-choice questionnaires on implant use completed independently by parents and teachers. SETTING: The study was performed at a dedicated pediatric cochlear implant program in a tertiary referral center in the United Kingdom. PATIENTS: All 85 consecutively implanted children who had reached the 1-year interval after implantation and 37 children who had reached the 3-year assessment interval after implantation participated. The patients represented all socioeconomic status groups, the entire range of educational settings, and often lived at a considerable distance from the implant center. MAIN OUTCOME MEASURES: Parents and local teachers were asked to describe implant use in the following categories: 1) all of the time; 2) most of the time; 3) some of the time; and 4) none of the time. RESULTS: One year after implantation, parents and teachers, respectively, rated 79 (93%) and 82 (96%) children as full-time users (category 1). Parents rated six children (7%) as users most of the time (category 2), and teachers rated three children (4%) as users most of the time. No child was rated as an occasional or nonuser (category 3 or 4). At 3 years after implantation, 33 (89%) and 34 (95%) children were rated as full-time users (category 1) by parents and teachers, respectively. Parents judged four children (11%) and teachers rated two children (5%) to be users most of the time (category 2). Again, no child was rated in category 3 or 4 as an occasional or nonuser. CONCLUSIONS: The majority of implanted children use their implant systems all of the time over a 3-year period after implantation when selected appropriately and given appropriate follow-up.     

A new quadruple therapy for the eradication of Helicobacter pylori. Effect of pretreatment with omeprazole on the cure rate

The aim of the study was to assess the speech discrimination ability of postlingually deaf adults implanted with the Combi 40 cochlear implant and to compare the results with the postoperative data published for other devices. The postoperative open and closed set speech perception performance of 21 consecutive patients was tested using a standardized test battery comprising a number, monosyllable, sentence, consonant and vowel discrimination test as well as a rhyme test in the sound only condition. Mean values achieved for each test 1, 6 and 12 months after "switch on" were evaluated. The results demonstrate that all patients have a substantial benefit from their implant and show a continuous improvement in their speech perception abilities with increased device experience. The mean percentages of correct answers after 12 months were 93.4 for numbers, 44.6 for monosyllables, 78.5 for sentences, 67.6 for the rhyme test, 59.8 for vowel, and 67.3 for consonant discrimination. Preoperatively, the mean discrimination score for monosyllables was 0%. The speech discrimination scores of our patients were similar or higher than described for similar patient groups implanted with other devices. The high stimulation rate of the implant system using the continuous interleaved speech processing strategy as well as a deep atraumatic electrode insertion into the apicalmost regions of the scala tympani may be the reason for good performance.     

Effects of noise and spectral resolution on vowel and consonant recognition: acoustic and electric hearing

Current multichannel cochlear implant devices provide high levels of speech performance in quiet. However, performance deteriorates rapidly with increasing levels of background noise. The goal of this study was to investigate whether the noise susceptibility of cochlear implant users is primarily due to the loss of fine spectral information. Recognition of vowels and consonants was measured as a function of signal-to-noise ratio in four normal-hearing listeners in conditions simulating cochlear implants with both CIS and SPEAK-like strategies. Six conditions were evaluated: 3-, 4-, 8-, and 16-band processors (CIS-like), a 6/20 band processor (SPEAK-like), and unprocessed speech. Recognition scores for vowels and consonants decreased as the S/N level worsened in all conditions, as expected. Phoneme recognition threshold (PRT) was defined as the S/N at which the recognition score fell to 50% of its level in quiet. The unprocessed speech had the best PRT, which worsened as the number of bands decreased. Recognition of vowels and consonants was further measured in three Nucleus-22 cochlear implant users using either their normal SPEAK speech processor or a custom processor with a four-channel CIS strategy. The best cochlear implant user showed similar performance with the CIS strategy in quiet and in noise to that of normal-hearing listeners when listening to correspondingly spectrally degraded speech. These findings suggest that the noise susceptibility of cochlear implant users is at least partly due to the loss of spectral resolution. Efforts to improve the effective number of spectral information channels should improve implant performance in noise.     

A preliminary study of the effects of cochlear implants on the production of sibilants

The potential influence of auditory information in the production of /s/ and /integral of/ was explored for postlingually deafened adults with four-channel Ineraid cochlear implants. Analyses of the spectra of the sibilant sounds were compared for speech obtained prior to implant activation, after early implant use and after 6 months of use. In addition, the output of the Ineraid device (measured at each of the four electrodes) was analyzed with pre- and postactivation speech samples to explore whether the speech production changes were potentially audible to the cochlear-implant user. Results indicated that subjects who showed abnormally low or incorrect contrast between /s/ and /integral of/ preactivation, and who received significant auditory benefit from their implants were able to increase the distinctiveness of their productions of the two speech sounds.     

The relation between electric auditory brain stem and cognitive responses and speech perception in cochlear implant users

Electrically evoked brainstem responses (EABR) and event-related cortical potentials were recorded in seven postlingually deaf adults who were experienced users of a Nucleus multichannel cochlear implant. The patients were divided into two subgroups: good performers and moderate performers. Poor EABR were found in two of the moderate performers. The latencies and amplitudes of the cortical N1 P2 complex in the good performers were within the same range as those of subjects with normal hearing, but were deviant in the group of moderate performers. This may indicate disturbed cochleotopical organization of the auditory cortex in the latter group. P300 measurements in the good performers showed normal latencies, whereas in the moderate performers they were prolonged. The results suggest that the outcomes of electrophysiological measurements to assess the integrity of a patient's auditory neural system on a brainstem and a cortical level, are related to the patient's performance with the cochlear implant.