Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lipreading”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1991

Cochlear implants: indications and technology.

Over the last decade, the field of cochlear implants has progressed to the point where many postlinguistically deaf adults can use a multichannel device to understand speech without lipreading. The remainder are able to use their devices to aid in lipreading and to discriminate environmental sounds. It is anticipated that improved processing schemes will be developed so that the cochlear implant user can expect better speech perception with these devices. Eventually, a more sophisticated cochlear implant that has the capability of permitting good speech discrimination may supplant hearing aids for severely deafened individuals. Regardless of future developments, the present-day systems effectively restore auditory function to profoundly deafened children and adults.

Cochlear Implants↗
PubMed1985

Categorical perception of speech sounds via the tactile mode.

The usefulness of tactile devices as aids to lipreading has been established. However, maximum usefulness in reducing the ambiguity of lipreading cues and/or use of tactile devices as a substitute for audition may be dependent on phonemic recognition via tactile signals alone. In the present study, a categorical perception paradigm was used to evaluate tactile perception of speech sounds in comparison to auditory perception. The results show that speech signals delivered by tactile stimulation can be categorically perceived on a voice-onset time (VOT) continuum. The boundary for the voiced-voiceless distinction falls at longer VOTs for tactile than for auditory perception. It is concluded that the procedure is useful for determining characteristics of tactile perception and for prosthesis evaluation.

Adult↗
PubMed1990

A comparison of two training strategies for speech recognition with an electrotactile speech processor.

Seven normally hearing adults were trained in the use of a multiple-channel electrotactile speech processor for 70 hours over a 6-month period. Two training strategies were used on each of the subjects: (1) analytic-plus-synthetic (AS), and (2) synthetic (S). The speech perception abilities of the subjects were assessed with closed sets of vowels and consonants, open sets of words and sentences, and speech tracking, for the tactile-plus-lipreading, tactile, and lipreading conditions. The subjects were tested on three separate occasions: (1) at the beginning of the study, (2) after 35 hours of training, and (3) after a further 35 hours of training. Wilcoxon matched-pair signed-ranks (MPSR) tests showed that improvements observed with both the AS and S strategies were significantly (p less than .05) greater than zero for most tests and conditions. The Wilcoxon MPSR test showed that the difference in improvements between the training strategies was significant for only the vowel and consonant tests in the tactile condition.

Adolescent↗
PubMed1988

[Hemianopsia and agnosia].

Hemianopsia and agnosia, the coexistence of a disorder of perception and a disorder of recognition, is exemplified by two patients chosen for their clinical similarity. These two patients each had a stroke, one of the left and the other of the right posterior cerebral artery, resulting right and left hemianopsia respectively. Primary visual functions such as visual acuity and contrast sensitivity were intact. The differences were only apparent as regards the severity of the agnostic disorders. The patient with the lesion on the left failed to recognize stylized drawings, was alexic, could not lipread and was color anomic, but could easily identify handwriting, faces, and voices. The patient with the right posterior lesion could not recognize handwriting, was prosopagnosic and topographagnosic, but had no difficulty in reading, lipreading, or in recognizing stylized drawings. The apparent double dissociation of function demonstrates the presence of two different visual processing mechanisms which are very probably peculiar to the visual system of the left hemisphere in the one case and to that of the right hemisphere in the other. The authors' findings suggest that the two cerebral hemispheres differ fundamentally in the way they process visual information.

Agnosia↗
PubMed1991

Role of a multichannel electrotactile speech processor in a cochlear implant program for profoundly hearing-impaired adults.

Four profoundly hearing-impaired adults who did not meet current selection criteria for implantation at the University of Melbourne were each fitted with a wearable multichannel electrotactile speech processor (Tickle Talker). The subjects were evaluated with a test battery of speech discrimination tests subsequent to training in use of the device. Thresholds for detection of pure tones were lower for the Tickle Talker than for hearing aids across the frequency range 250 to 4000 Hz. Mean speech detection thresholds for the Ling 5-sound test showed that all sounds were detected by users of the electrotactile device at normal conversational speech intensity levels. Mean speech discrimination scores were significantly higher (p less than 0.05) in the tactually aided condition as compared with the tactually unaided for identification of vowels and consonants, on open-set words, open-set sentences, and on connected discourse tracking. Mean scores increased by 20% for vowels, 19% for consonants, 30% for open-set words, and 25% for open-set sentences when the Tickle Talker was used in a multimodal combination with lipreading or lipreading and hearing aids. Speechtracking rates for three subjects showed increases of from 18 to 28 wpm when the tactile device was used. Comparison of tactually aided versus unaided tracking rates for two subjects with long-term experience shows continuing improvement with additional experience with the device. These results demonstrate that hearing-impaired adults not meeting selection criteria for cochlear implantation may benefit from use of an electrotactile speech processor, and highlight the potential benefits from integration of such devices into cochlear implant programs for profoundly hearing-impaired patients.

Acoustics↗
PubMed2002

Results from a European clinical investigation of the Nucleus multichannel auditory brainstem implant.

OBJECTIVE: This study was designed to investigate the perceptual benefits and potential risks of implanting the Nucleus(R) multichannel auditory brainstem implant. DESIGN: Between September 1992 and October 1997 a total of 27 subjects received a Nucleus 20- or 21-channel Auditory Brainstem Implant (ABI). All subjects involved in the trial had bilateral acoustic tumour as a result of neurofibromatosis type 2 (NF2) resulting in complete dysfunction of the VIIIth nerve. The study used each subject as their own control without a preoperative baseline because residual hearing, if existing, was destroyed at surgery by tumour removal. A battery of speech tests was conducted to evaluate each patient's performance and communication abilities. Tests were conducted, where possible, in the auditory-only, visual-only, and auditory-visual conditions at 3 days postoperatively (baseline), at 3-mo intervals for the first year and every 12 mo thereafter. A subjective performance questionnaire was administered together with an extensive neurological examination at each test interval. RESULTS: 27 subjects involved in this trial were successfully implanted with a Nucleus ABI. One subject died 2 days postoperatively due to a lung embolism unrelated to the device. Twenty-six subjects underwent device activation and all but one patient received auditory sensation at initial stimulation (96.2%). On average 8.6 (+/-4.2) of the available 21 electrodes were used in the patients' MAPs. Performance evaluation measures showed that the majority of users had access to auditory information such as environmental sound awareness together with stress and rhythm cues in speech that assist with lipreading. Although most subjects did not achieve any functional auditory-alone, open-set speech understanding, two subjects from this series (7.4%) did receive sufficient benefit to be able to use the ABI in conversation without lipreading. CONCLUSIONS: Although the medical risks and surgical complexity associated with ABI device implantation are far greater than those for a cochlear implant, the clinical results from this trial show that the Nucleus multichannel ABI is capable of providing a significant patient benefit over risk ratio for subjects suffering loss of hearing due to bilateral retrocochlear lesions.

Acoustic Stimulation↗
PubMed1987

Vowel and consonant recognition of cochlear implant patients using formant-estimating speech processors.

Vowel and consonant confusion matrices were collected in the hearing alone (H), lipreading alone (L), and hearing plus lipreading (HL) conditions for 28 patients participating in the clinical trial of the multiple-channel cochlear implant. All patients were profound-to-totally deaf and "hearing" refers to the presentation of auditory information via the implant. The average scores were 49% for vowels and 37% for consonants in the H condition and the HL scores were significantly higher than the L scores. Information transmission and multidimensional scaling analyses showed that different speech features were conveyed at different levels in the H and L conditions. In the HL condition, the visual and auditory signals provided independent information sources for each feature. For vowels, the auditory signal was the major source of duration information, while the visual signal was the major source of first and second formant frequency information. The implant provided information about the amplitude envelope of the speech and the estimated frequency of the main spectral peak between 800 and 4000 Hz, which was useful for consonant recognition. A speech processor that coded the estimated frequency and amplitude of an additional peak between 300 and 1000 Hz was shown to increase the vowel and consonant recognition in the H condition by improving the transmission of first formant and voicing information.

Cochlear Implants↗
PubMed1990

Perception of sentences, words, and speech features by profoundly hearing-impaired children using a multichannel electrotactile speech processor.

Fourteen prelinguistically profoundly hearing-impaired children were fitted with the multichannel electrotactile speech processor (Tickle Talker) developed by Cochlear Pty. Ltd. and the University of Melbourne. Each child participated in an ongoing training and evaluation program, which included measures of speech perception and production. Results of speech perception testing demonstrate clear benefits for children fitted with the device. Thresholds for detection of pure tones were lower for the Tickle Talker than for hearing aids across the frequency range 250-4000 Hz, with the greatest tactual advantage in the high-frequency consonant range (above 2000 Hz). Individual and mean speech detection thresholds for the Ling 5-sound test confirmed that speech sounds were detected by the electrotactile device at levels consistent with normal conversational speech. Results for three speech feature tests showed significant improvement when the Tickle Talker was used in combination with hearing aids (TA) as compared with hearing aids along (A). Mean scores in the TA condition increased by 11% for vowel duration, 20% for vowel formant, and 25% for consonant manner as compared with hearing aids alone. Mean TA score on a closed-set word test (WIPI) was 48%, as compared with 32% for hearing aids alone. Similarly, mean WIPI score for the combination of Tickle Talker, lipreading, and hearing aids (TLA) increased by 6% as compared with combined lipreading and hearing aid (LA) scores. Mean scores on open-set sentences (BKB) showed a significant increase of 21% for the tactually aided condition (TLA) as compared with unaided (LA). These results indicate that, given sufficient training, children can utilize speech feature information provided through the Tickle Talker to improve discrimination of words and sentences. These results indicate that, given sufficient training, children can utilize speech feature information provided through the Tickle Talker to improve discrimination of words and sentences. These results are consistent with improvement in speech discrimination previously reported for normally hearing and hearing-impaired adults using the device. Anecdotal evidence also indicates some improvements in speech production for children fitted with the Tickle Talker.

Adolescent↗
PubMed1992

Factors predicting postoperative sentence scores in postlinguistically deaf adult cochlear implant patients.

A sample of 64 postlinguistically profoundly to totally deaf adult cochlear implant patients were tested without lipreading by means of the Central Institute for the Deaf (CID) sentence test 3 months postoperatively. Preoperative promontory stimulation results (thresholds, gap detection, and frequency discrimination), age, duration of profound deafness, cause of deafness, lipreading ability, postoperative intracochlear thresholds and dynamic ranges for electrical stimulation, depth of insertion of the electrode array into the scala tympani, and number of electrodes in use were considered as possible factors that might be related to the postoperative sentence scores. A multiple regression analysis with stepwise inclusion of independent variables indicated that good gap detection and frequency discrimination during preoperative promontory testing, larger numbers of electrodes in use, and greater dynamic ranges for intracochlear electrical stimulation were associated with better CID scores. The CID scores tended to decrease with longer periods of profound deafness.

Adolescent↗
PubMed1981

A multiple-channel cochlear implant: an evaluation using open-set CID sentences.

A multiple-channel cochlear implant and speech processor have been used in two postlingually deaf adult patients with a total hearing loss, to enable them to perceive varying degrees of running speech. The results have veen confirmed with open-set CID everyday sentence tests. Using the implant alone, the patients obtained 8% and 14% scores with prerecorded material, and 34% and 36% scores for "live" presentations. This was equivalent to the perception of 35% of connected discourse. When the implant was used in conjuction with lipreading, improvements of 188% and 386% were obtained over lipreading alone, and the scores were 68% and 98% which were equivalent to the perception of 60% and 95% of connected discourse.

Adult↗
PubMedDate not supplied

A multiple-channel cochlear implant and wearable speech-processor: an audiological evaluation.

Stand audiological tests were administered to a totally deaf multiple-channel cochlear implant patient with a wearable speech-processor in a monitored sound field under the following conditions: a wearable unit activated alone (WA), lipreading with the wearable unit off (LA), and wearable unit activated in combination with lipreading (WL). Thresholds obtained for narrow-band noise signals indicated that the wearable unit allowed the patient to detect a variety of sounds at different frequencies. The results obtained in closed-set word tests and open-set word and sentence tests showed significant improvements in word and sentence scores from LA to WL. In the open-set (C.I.D.) sentence test, the patient scored 22% for LA and 76% for WL. The WL score of 76% correlates with a satisfactory performance in understanding connected speech. The patient also scored 30% correct in a test involving the recognition of environmental sounds.

Cochlear Implants↗
PubMed1986

Speech perception with the Vienna extra-cochlear single-channel implant: a comparison of two approaches to speech coding.

Although it is generally accepted that single-channel electrical stimulation can significantly improve a deafened patient's speech perceptual ability, there is still much controversy surrounding the choice of speech processing schemes. We have compared, in the same patients, two different approaches: (1) The speech pattern extraction technique of the EPI group, London (Fourcin et al., British Journal of Audiology, 1979,13,85-107) in which voice fundamental frequency is extracted and presented in an appropriate way, and (2) The analogue 'whole speech' approach of Hochmair and Hochmair-Desoyer (Annals of the New York Academy of Sciences, 1983, 405, 268-279) of Vienna, in which the microphone-sensed acoustic signal is frequency-equalized and amplitude-compressed before being presented to the electrode. With the 'whole-speech' coding scheme (which they used daily), all three patients showed an improvement in lipreading when they used the device. No patient was able to understand speech without lipreading. Reasonable ability to distinguish voicing contrasts and voice pitch contours was displayed. One patient was able to detect and make appropriate use of the presence of voiceless frication in certain situations. Little sensitivity to spectral features in natural speech was noted, although two patients could detect changes in the frequency of the first formant of synthesised vowels. Presentation of the fundamental frequency only generally led to improved perception of features associated with it (voicing and intonation). Only one patient consistently showed any advantage (and that not in all tests) of coding more than the fundamental alone.

Adult↗
PubMedDate not supplied

A multi-channel hearing prosthesis for profound-to-total hearing loss.

A multi-channel cochlear implant hearing prosthesis providing 22 separate channels of stimulation has been developed. The electronics for the implantable receiver-stimulator have been incorporated on a single chip, using digital circuits and employing CMOS technology. The chip is enclosed in a titanium capsule with platinum/ceramic electrode feed-throughs. A pocket-sized speech processor and directional microphone extract the following speech parameters: signal amplitude, fundamental frequency and formant frequency. The fundamental frequency is coded as electric pulse rate, and formant frequency by electrode position. The speech processor has been realized using hybrid circuits and CMOS gate arrays. The multi-channel prosthesis has undergone a clinical trial on four postlingually deaf patients with profound-total hearing losses. The speech perception results indicate that they were able to obtain open-set speech recognition scores for phonetically balanced words, CID sentences and spondees. In all cases the tests showed significant improvements when using the cochlear prosthesis combined with lipreading compared to lipreading alone.

Adult↗
PubMed2002

Multichannel auditory brainstem implant: update on performance in 61 patients.

OBJECT: Neurofibromatosis Type 2 (NF2) has typically resulted in deafness after surgical removal of bilateral vestibular schwannomas (VSs). Cochlear implants are generally ineffective for this kind of deafness because of the loss of continuity in the auditory nerve after tumor removal. The first auditory brainstem implant (ABI) in such a patient was performed in 1979 at the House Ear Institute, and this individual continues to benefit from electrical stimulation of the cochlear nucleus complex. In 1992, an advanced multichannel ABI was developed and a series of patients with NF2 received this implant to study the safety and efficacy of the device. METHODS: At the time of first- or second-side VS removal, patients received an eight-electrode array applied to the surface of the cochlear nucleus within the confines of the lateral recess of the fourth ventricle. The device was activated approximately 6 weeks after implantation. and patients were tested every 3 months for the 1st year after the initial stimulation, and annually thereafter. The protocol included a comprehensive battery of psychophysical and speech perception tests. CONCLUSIONS: The multichannel ABI proved to be effective and safe in providing useful auditory sensations in most patients with NF2. The ABI improved patients' ability to communicate compared with the lipreading-only condition, it allowed the detection and recognition of many environmental sounds, and in some cases it provided significant ability to understand speech by using just the sound from the ABI (with no lipreading cues). Its performance in most patients has continued to improve for up to 8 years after implantation.

Adolescent↗
PubMed2000

[Factors influencing satisfaction of cochlear implant users--a questionnaire-based study].

We surveyed on cochlear implant (CI) users using a questionnaire to determine how they use their CIs in daily life and to what degree they are satisfied with them. We also studied the relationship between the degree of satisfaction and speech perception score, age at operation, and deafness duration. Subjects were 37, postlingually-deafened adult CI users were subjected to this study. Average CI use per day was 13.6 hours. Some 60% of subjects understood person-to-person conversation without lipreading, but most could not communicate on the telephone, in meetings, or in noisy places, for example. Most--about 80%--were satisfied with CI, but 20% were not. Those not satisfied tended to be unable to understand person-to-person conversation even with CI and lipreading, indicating that understanding person-to-person conversation is one of the most important reasons for satisfaction in CI users. Speech recognition scores improved in all cases after implantation. Most patients with high speech recognition score-->40% in consonant recognition--were satisfied with CI, but those with recognition scores < 40% in consonant recognition, the degree of satisfaction varied. These results indicate that the degree of satisfaction in CI users does not always correspond to the degree of improvement in speech recognition score. Two patients not satisfied with CI had undergone surgery after the age of 65 years and deafness duration exceeding 20 years. Advanced age and a long deafness duration may thus reduce satisfaction with CIs.

Adult↗
PubMed1989

[Single channel cochlear implant: application to three patients].

Single channel cochlear implant of 3M/House design was implanted to the three patients with profound hearing loss. Before the implantation, use of hearing aid had not afforded serviceable hearing enough for speech recognition in these patients. Postoperative courses were uneventful. Speech rehabilitation was started at 3 weeks after the surgery. The speech tracking scores with the cochlear implant plus lipreading achieved 20-25 bunsetues (the minimum meaningful unit of the Japanese sentence) per minute at three or four months after the operation. All the patients could recognize speech of daily life with help of lipreading. However, speech recognition by the cochlear implant alone was not satisfactory.

Adult↗
PubMed2000

The influence of residual high-frequency hearing on the outcome in congenitally deaf cochlear implant recipients.

OBJECTIVE: To show that congenitally deaf children who receive a cochlear implant between 10 and 15 years of age find it significantly more difficult to learn the new signal, and that a history of sound detection at high frequencies with hearing aids is predictive of better outcomes in these children. STUDY DESIGN: A retrospective study using a within-subjects design. SETTING: Children's Cochlear Implant Centre, Sydney (CCIC), Royal Prince Alfred Hospital, and the New Children's Hospital in Westmead are tertiary referral centers. PATIENTS: Forty-five congenitally deaf patients were grouped according to their age (in years) at implantation into group 1 (aged 10-15), group 2 (aged <10), group 2a (aged 6-9), and group 2b (aged 3-5). Within each group, individuals with previous hearing between 2 and 4 kHz before receiving a cochlear implant were identified, and their mean results were compared with those in their respective age-matched groups. INTERVENTIONS: Surgical implantation, intensive weekly habilitation at the CCIC. MAIN OUTCOME MEASURES: Speech perception, speech production, and language measures were compared. Questionnaires and telephone interviews were conducted. RESULTS: Group 2 (age <10 years) consistently outperformed group 1 (10-15 years) on all outcome measures, and most of them learned to converse without lipreading. In group 1, children with previous aided hearing at high frequencies displayed exceptional gains in speech perception and speech production, with reduced dependence on lipreading. Previous high-frequency hearing does not benefit group 2. CONCLUSIONS: Implant recipients aged 10 to 15 years experience more difficulty than younger children during the initial periods of device use. A history of high-frequency hearing before implantation in these individuals correlates with more rapid improvement.

Adolescent↗
PubMed1986

Continuing evaluation of the Queen's University tactile vocoder. I: Identification of open set words.

Identification of open set words, by an experienced normal hearing subject using the tactile vocoder developed at Queen's University, was examined. The tactile vocoder filters and processes the acoustic waveform into 16 filter channels, each of which controls a vibrator on the skin surface. After acquiring a 250-word vocabulary through the tactile vocoder, the subject was presented with three sets of 1000 different open set words in three reception conditions. The percentages of words correctly identified in the tactile vocoder (TV), lipreading (L), and lipreading plus tactile vocoder (L + TV) conditions were 8.8, 39.4, and 68.7 percent respectively. Phonemic analysis of stimulus/response pairs revealed that 36.7, 64.9 and 85.5 percent of the phonemes were correctly identified in TV, L, and L + TV conditions, respectively, indicating that incorrect-response words often contained many correct phonemes. Also, syllabic stress of stimulus and response words was identical 88 percent of the time in the TV condition. Important information about speech was transmitted through the tactile vocoder.

Deafness↗