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PubMed1992

The neuropsychology of lipreading.

Lipreading presents a unique glimpse of the intersection of sensory processes with modular, cognitive ones. It presents speech to the eye in an automatic and natural way, whether performed silently or in conjunction with heard speech. It therefore allows us to examine closely claims concerning the relation between input modality and cognitive function. In this paper I consider some of the ways in which the investigation of single neuropsychological cases casts light on this; such cases show us that lipreading can dissociate from other aspects of face perception and recognition, and from auditory speech perception and reading, too. Furthermore, different cognitive components of lipreading itself can be inferred from dissociations on different lipreading tasks. This leads to closer consideration of the boundaries of the necessary cognitive (and possibly anatomical) structures that subserve these functions.

Brain↗
PubMed1991

Peripheral vision lipreading aid.

Lipreading provides a limited amount of information about speech signals to profoundly deaf people. Visual displays using peripheral vision as an alternative sensory modality can provide supplementary speech information. The utility of a cosmetically acceptable peripheral vision display was explored. A pair of eyeglasses with a commercially available two-dimensional red LED array (5 x 7), and its associated electronics was developed. The display is visible only to the wearer, and is located in the temporal field and the horizontal meridian of the right eye. Selected speech features were encoded as visual patterns for presentation to the lipreader. These features of the speech signal (the fundamental frequency of the speech, high-frequency energy, and low-passed speech signal or total energy envelope) were presented with the objective of providing information about voicing and plosion/frication. Experiments demonstrate the capability of the peripheral display in conveying speech information. Presenting vowel-consonant-vowel syllables, the performance was in excess of 76% with aided lipreading as compared to 41% by lipreading only.

Communication Devices for People with Disabilities↗
PubMed2005

Tactual display of consonant voicing as a supplement to lipreading.

This research is concerned with the development and evaluation of a tactual display of consonant voicing to supplement the information available through lipreading for persons with profound hearing impairment. The voicing cue selected is based on the envelope onset asynchrony derived from two different filtered bands (a low-pass band and a high-pass band) of speech. The amplitude envelope of each of the two bands was used to modulate a different carrier frequency which in turn was delivered to one of the two fingers of a tactual stimulating device. Perceptual evaluations of speech reception through this tactual display included the pairwise discrimination of consonants contrasting voicing and identification of a set of 16 consonants under conditions of the tactual cue alone (T), lipreading alone (L), and the combined condition (L + T). The tactual display was highly effective for discriminating voicing at the segmental level and provided a substantial benefit to lipreading on the consonant-identification task. No such benefits of the tactual cue were observed, however, for lipreading of words in sentences due perhaps to difficulties in integrating the tactual and visual cues and to insufficient training on the more difficult task of connected-speech reception.

Adult↗
PubMed2001

The effects of irrelevant speech and articulatory suppression on the serial recall of silently presented lipread digits.

The immediate serial recall of lipread material is disrupted by irrelevant speech (Campbell & Dodd, 1984; Jones, 1994) and by articulatory suppression (Campbell & Dodd, 1984). However, the interaction between these has not been directly examined. In Exp 1, participants recalled silently presented lipread digits in conditions of quiet, irrelevant speech, articulatory suppression and suppression/speech combined. Irrelevant speech disrupted recall, but not when articulation was suppressed. Experiment 2 demonstrated that participants were able to accurately lipread targets in all of the above experimental conditions. A third experiment contrasted predictions derived from the phonological loop model (PL; Baddeley, 1986) and the changing state hypothesis (CSH; Jones, 1993). The CSH predicts that tones and speech that vary in frequency to the same degree will disrupt recall equally (Jones & Macken, 1993), whereas the PL model implies that speech will always be more disruptive. The results support the CSH, and extend the findings of Jones and Macken (1993) to account for lipread stimuli. As with graphic presentation, the CSH provides a better account of the processes underpinning the irrelevant speech effect; however, it is argued that the recoding hypothesis from the PL model should be retained.

Adolescent↗
PubMed1991

Measurement of performance of a peripheral vision lipreading aid.

Lipreading, as the most important tool of speech understanding for profoundly deaf people, carries only a limited amount of information about speech. We explored the usefulness of a peripheral vision display in providing profoundly deaf people with supplementary information to lipreading. A pair of eye-glasses with a commercially available two-dimensional red LED array, and associated electronics was developed. The display is located on the rim of the eyeglasses in the temporal field and the horizontal meridian of the right eye. Selected speech features were encoded as visual patterns for presentation to the lipreader. These features (the fundamental frequency of the speech, high-frequency energy, and low-passed speech signal or total energy envelope) provide information about voicing and plosion/friction in order to supplement lipreading. Experiments with 3 normal and 5 deaf subjects demonstrated the capability of the aid to convey speech information for video taped vowel-consonant-vowel (VCV) nonsense syllables. Average identification of 12 VCV syllables using the aid was about 76%, as compared with 40% without the aid.

Adolescent↗
PubMed1996

Lipreading, reading and memory of hearing and hearing-impaired children.

The relationship between lipreading, reading and visual and sequential memory was investigated in hearing 10-year-olds and two groups of hearing-impaired 10-year-olds, one educated through the medium of English and the other through British Sign Language. The scores and the pattern of correlations between the variables were hypothesized to be different in the three groups and this was found to be the case. In the case of the hearing, visual memory for complex shapes was significantly correlated with lipreading. For the oral deaf, reading ability was significantly correlated with lipreading, but for the bilingual deaf the correlation was not significant. The possible implications of these findings for the relationships between the cognitive processes involved in lipreading and for the education of the deaf are discussed.

Child↗
PubMed1986

Disruptive effects of auditory signal delay on speech perception with lipreading.

The effect of auditory signal delay on audio-visual perception of videotaped sentence lists by Ss with normal hearing was measured. The test material consisted of sentences read by a man, with or without a picture representing as context one of the key words in each sentence. In Exper. I, 12 Ss (6M, 6F), inexperienced with lipreading, were presented test material in the audio-only (A), visual-only (V) and audio-visual (AV) modes. Speech signals were presented at 0 or -10 db S/N re a multitalker babble fixed at 60 dbA. The audio signal was delayed (re visual signal) in 6 steps from 0-300 msec. Exper. II repeated Exper. I with 6 Ss (2M, 4F) familiar with lipreading; the speech signal was presented at -5 db S/N and 4 audio delays from 0-240 msec. While these Ss performed better in the V mode than those in Exper. I, the main effects of context and delays were similar. The disruptive effect of the audio delay on speech perception with lipreading (AV mode) was a function of S/N, being relatively more disruptive at the worse S/N, but it was not significant for delays up to a range of 80-120 msec. The results are in agreement with the theory (McGrath and Summerfield, J. Acoust. Soc. Am., 1985, 77, 678-685) that sensitivity to audio-visual desynchrony is significant only at a syllabic level in connected speech. The results further imply that moderate delays of up to 80 msec introduced by speech-processing aids for lipreading, as for cochlear-implanted patients, will not interfere with the advantages of providing the auditory information.

Acoustic Stimulation↗
PubMed1986

Lipreading with tactile supplements.

Lipreading performance, after brief training, was measured in two normal subjects, as the percentage of words recognized in sets of unrelated sentences. Three receptive conditions were used: lipreading alone, lipreading plus a single-channel tactile display of fundamental frequency (temporal only), and lipreading plus a multichannel, tactile, spatial display of fundamental frequency (temporal-spatial). After training, performance with tactile supplements was better than without, but it was not possible to conclude that either of the tactile displays was better than the other. During training, a significant correlation between performance and session number was found for the temporal-spatial display only.

Female↗
PubMed1976

Effects of sentence context on recognition of words through lipreading by deaf children.

Twenty monosyllabic nouns (10 animate, 10 inanimate) were presented in isolation and in three different positions in sentences to 15 profoundly deaf children to determine the effect of context on word intelligibility through lipreading. Isolated words were more intelligible (80%) than were words in sentences (46%). Animate nouns were more intelligible (70%) than inanimate nouns (33%) when used in initial position (as subjects) in sentences. Teacher ratings of children's "general lipreading ability" were correlated more highly with their recognition of words in the test sentences (r = 0.93) than with their recognition of words presented in isolation (r = 0.53). The results indicate that teachers of deaf children could enhance the intelligibility of important words by isolating them from sentences. The results also suggest that some speech-perception difficulties of deaf children could be diagnosed through lipreading tests which are scored on the basis of correctness of "key words" in sentences.

Adolescent↗
PubMed1986

Face recognition and lipreading. A neurological dissociation.

Two cases with medial occipitotemporal ischaemic infarction in the territory of the posterior cerebral artery are discussed; neither was aphasic. The patient with the right-sided lesion is prosopagnosic and topographagnosic and is impaired at recognizing or classifying facial expressive gestures but can lipread speech efficiently. The other patient, with only a left-sided lesion, shows no deficits in face recognition nor in the classification of faces in terms of nonverbal messages, but is alexic and impaired at lipreading. It is argued that processing faces for verbal information (lipreading) and processing faces for nonverbal information (face recognition and interpretation of emotive and gestural messages) are functionally dissociated in the human brain. Theoretical interpretations of prosopagnosia that stress a perceptual component to all types of face recognition failure may therefore be misleading, for similar stimulus processing mechanisms are likely to be required to identify a speech sound from a face as to identify a nonverbal gesture of the mouth. Only the associative properties of the task differ.

Aged↗
PubMed1983

Physical characteristics of the lips underlying vowel lipreading performance.

To evaluate the relationship between physical characteristics of the lips during vowel production and vowel lipreading confusions, four female talkers were videotaped producing 15 American English vowels and diphthongs in an /h/-V-/g/ context. Ten normal-hearing adults identified the stimuli through lipreading. Three analyses were performed. First, using confusion matrices for individual and pooled talkers, the stimuli were located in a two-dimensional space using multidimensional scaling. The ten monophthongs revealed a clear lip spreading/rounding dimension and a tongue height dimension, and while diphthongs also showed influence of lip rounding, more variability on the tongue height dimension was apparent. Second, tracings were made of the talkers' lips on a single videotape field representing the maximum opening or constriction for each of the 40 monophthong tokens (ten vowels X four talkers), and six physical measurements of the tokens were derived as descriptors of the vowel nuclei. Third, difference scores and other measures of physical pairwise similarity were used as predictors of two ways of representing the vowel lipreading confusions in a multiple regression paradigm. Results indicated that the physical measures were moderately successful as predictors of vowel perception (accounting for approximately 50% of the variance in the perceptual distance measure), although considerable differences in the strength of the prediction occurred among talkers.

Lip↗
PubMed1991

Lipreading sentences with vibrotactile vocoders: performance of normal-hearing and hearing-impaired subjects.

Three vibrotactile vocoders were compared in a training study involving several different speech perception tasks. Vocoders were: (1) the Central Institute for the Deaf version of the Queen's University vocoder, with 1/3-oct filter spacing and logarithmic output scaling (CIDLog) [Engebretson and O'Connell, IEEE Trans. Biomed. Eng. BME-33, 712-716 (1986)]; (2) the same vocoder with linear output scaling (CIDLin); and (3) the Gallaudet University vocoder designed with greater resolution in the second formant region, relative to the CID vocoders, and linear output scaling (GULin). Four normal-hearing subjects were assigned to either of two control groups, visual-only control and vocoder control, for which they received the CIDLog vocoder. Five normal-hearing and four hearing-impaired subjects were assigned to the linear vocoders. Results showed that the three vocoders provided equivalent information in word-initial and word-final tactile-only consonant identification. However, GULin was the only vocoder significantly effective in enhancing lipreading of isolated prerecorded sentences. Individual subject analyses showed significantly enhanced lipreading by the three normal-hearing and two hearing-impaired subjects who received the GULin vocoder. Over the entire training period of the experiment, the mean difference between aided and unaided lipreading of sentences by the GULin aided hearing-impaired subjects was approximately 6% words correct. Possible explanations for failure to confirm previous success with the CIDLog vocoder [Weisenberger et al., J. Acoust. Soc. Am. 86, 1764-1775 (1989)] are discussed.

Adult↗
PubMedDate not supplied

Perception of connected speech without lipreading, using a multi-channel hearing prosthesis.

Four of 13 totally deaf patients implanted with the Nucleus multi-channel hearing prosthesis at the University of Melbourne have demonstrated the ability to understand connected speech without lipreading or other visual cues. These patients were able to repeat verbatim unknown material read by a tester at rates of up to 35 words per minute. They were also able to understand an average of 78% of key words in everyday sentences in ideal acoustic conditions and 51% of equivalent material over the telephone. These results show that with a good proportion of postlingually deaf patients, the multi-channel hearing prosthesis can not only act as an aid to lipreading, but also restore effective speech understanding without lipreading.

Adult↗
PubMed1982

A video-recorded test of lipreading for British English.

Tests of lipreading are valuable in many applications, particularly with hearing impaired people. Desirable properties of such a test are outlined, and the deficiencies of present tests noted. All the stated criteria are met by a new video recording of the BKB sentence lists. A calibration study with 22 normally-hearing subjects shows that 12 of the 21 lists may be considered equally difficult. Different scoring methods are investigated, including a subjective technique. Correlations among all the scoring methods are high. Practice effects can be large, and vary with lipreading ability. While low scorers show little increase in performance over the set of lists, high scorers show big improvements. Two examples of the test's usefulness are detailed--one from the laboratory and one from the clinic. Both demonstrate that hearing which would not lead to significant speech perception on its own can still greatly improve lipreading ability.

Cues↗
PubMed1976

Acquisition of lipreading in a deaf multihandicapped child.

Operant techniques were used to develop lipreading in a nine-year-old deaf boy who had failed to respond appropriately to previous speechreading training. Remediation was initiated with two experiments: the first entailed a reversal and the second a multiple baseline. A component analysis revealed that both tokens and social reinforcers presented simultaneously or separately were effective in shaping lipreading. In addition, the child learned to lip-read either voiced or nonvoiced names of objects.

Affective Symptoms↗
PubMed1976

Visual intelligibility of consonants: a lipreading screening test with implications for aural rehabilitation.

A lipreading screening test consisting of 100 consonant-vowel (CV) syllables was prepared on videotape and presented to subjected with normal hearing and vision. The results of visual consonant confusions revealed nine homophenous categories with high test-retest reliability. Based upon these categories, obtained under ideal viewing conditions, criterion levels of performance were specified in an attempt to determine the need for place of articulation instruction during lipreading training. Examples of confusion patterns from hearing-impaired observers are shown and implications for visual training are presented.

Deafness↗
PubMed1987

Effects of consonantal context on vowel lipreading.

The effects of consonantal context on vowel lipreading were assessed for 30 adults with mild-to-moderate sensorineural hearing loss who lipread videotape recordings of two female talkers. The stimuli were the vowels /i,I,alpha,U,u/ in symmetric CVC form with the consonants /p,b,f,v,t,d,f,g/ and in the asymmetric consonantal contexts /h/-V-/g/, /w/-V-/g/, /r/-V-/g/. Analyses of the confusion matrices from each talker indicated that vowel intelligibility was significantly poorer in most contexts involving highly visible consonants, although the utterances of one talker were highly intelligible in the bilabial context. Among the visible contexts, the fricative and labiodental contexts in particular produced the lowest vowel intelligibility regardless of talker. Lax vowels were consistently more difficult to perceive than tense vowels. Implications for talker selection and refinement of the concept of viseme were drawn.

Adult↗
PubMed1995

Linking visual and kinesthetic imagery in lipreading instruction.

The purpose of this study was to replicate van Uden's (1983) finding that watching oneself speak improves lipreading of visually confusable nonsense words. Specifically, this replication focused on an older group of subjects whose educational experience varied widely in the emphasis given to spoken communication. Four groups of 12 young-adult subjects who are deaf participated in evaluating two aspects of training: (a) source of video feedback (self or trainer), and (b) timing of feedback (during speech production or after speech production). Mean posttest results indicated significantly increased accuracy in identifying items that had been trained. The group that viewed self-speech after speech-production practice also demonstrated generalization to test items that were not trained. On the combined list of both trained and untrained items, both groups that viewed their own speech achieved significant gains compared to pretest scores, but those that viewed the trainer's speech did not. Response time (RT) during pre- and posttesting was measured using a computer-generated waveform display to calculate the interval between stimulus offset and response onset. Results are reported for 13 subjects with > or = 50% speech intelligibility for words in sentences. Although there were no differences attributable to training conditions, there was an overall increase in the regularity of the identification responses after training (measured by the standard deviation of RTs) and a generalization of the improvement to the untrained items. The results of this study substantiate the beneficial effects of multisensory feedback by practicing lipreading of one's own speech production. This finding appears to apply even to young-adult subjects who are deaf and whose habituated speech patterns may be quite distinct from those of talkers with normal hearing.

Adolescent↗