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At least 55 records · Page 3Linked to original sources
PubMed1988

A new protocol for assessing viseme perception in sentence context: the lipreading discrimination test.

Forty-six hearing-impaired young adults were tested with a newly developed instrument that requires a discrimination response to assess viseme perception as a component of lipreading performance. Stimuli were videotaped sentences that differed on half of the trials from a captioned target sentence by one viseme embedded in the middle of the sentence. Discrimination within six visual categories was tested: gross syllable pattern, consonant articulation--lips, consonant articulation--tongue, vowel articulation--extreme lip shapes, vowel articulation--graded lip shapes, and vowel articulation--jaw movement. Test data were analyzed using an item response theory model. The results indicated that the test data conformed to the expectations of the Rasch model for person measurement. Relationships among subjects' test scores and communication characteristics also were examined. The data provide evidence that the test protocol, at this early stage of development, is useful for assessing at least one perceptual component of lipreading performance.

Adult↗
PubMed1992

Lipreading in patients with schizophrenia.

This study was designed to explore whether schizophrenic patients who are able to maintain their gaze with adequate persistence could competently lip-read. Four lipreading tests, designed to assess recognition of syllables, words, and overlearned sentences, were administered to 15 schizophrenic and 15 normal subjects matched for age, sex, and educational level. The patients proved to be competent lip-readers susceptible to the blend illusion and were inferior only in lipreading of overlearned sentences. The latter difficulty may tentatively be attributed to the inadequacy of the patient's premorbid social network for establishing contextual cues that aid in the recognition of overlearned sentences.

Adult↗
PubMed1992

Lipreading and audio-visual speech perception.

This paper reviews progress in understanding the psychology of lipreading and audio-visual speech perception. It considers four questions. What distinguishes better from poorer lipreaders? What are the effects of introducing a delay between the acoustical and optical speech signals? What have attempts to produce computer animations of talking faces contributed to our understanding of the visual cues that distinguish consonants and vowels? Finally, how should the process of audio-visual integration in speech perception be described; that is, how are the sights and sounds of talking faces represented at their conflux?

Auditory Perception↗
PubMed1999

A space-time delay neural network for motion recognition and its application to lipreading.

Motion recognition has received increasing attention in recent years owing to heightened demand for computer vision in many domains, including the surveillance system, multimodal human computer interface, and traffic control system. Most conventional approaches classify the motion recognition task into partial feature extraction and time-domain recognition subtasks. However, the information of motion resides in the space-time domain instead of the time domain or space domain independently, implying that fusing the feature extraction and classification in the space and time domains into a single framework is preferred. Based on this notion, this work presents a novel Space-Time Delay Neural Network (STDNN) capable of handling the space-time dynamic information for motion recognition. The STDNN is unified structure, in which the low-level spatiotemporal feature extraction and high-level space-time-domain recognition are fused. The proposed network possesses the spatiotemporal shift-invariant recognition ability that is inherited from the time delay neural network (TDNN) and space displacement neural network (SDNN), where TDNN and SDNN are good at temporal and spatial shift-invariant recognition, respectively. In contrast to multilayer perceptron (MLP), TDNN, and SDNN, STDNN is constructed by vector-type nodes and matrix-type links such that the spatiotemporal information can be accurately represented in a neural network. Also evaluated herein is the performance of the proposed STDNN via two experiments. The moving Arabic numerals (MAN) experiment simulates the object's free movement in the space-time domain on image sequences. According to these results, STDNN possesses a good generalization ability with respect to the spatiotemporal shift-invariant recognition. In the lipreading experiment, STDNN recognizes the lip motions based on the inputs of real image sequences. This observation confirms that STDNN yields a better performance than the existing TDNN-based system, particularly in terms of the generalization ability. In addition to the lipreading application, the STDNN can be applied to other problems since no domain-dependent knowledge is used in the experiment.

Algorithms↗
PubMed1990

Evaluation of the Craig Lipreading Inventory.

Responses to the Craig Lipreading Inventory have not been subjected to rigorous statistical analysis. No normative data currently exist. The purposes of this study were to evaluate the internal validity and interest reliability and to obtain normative data. The inventory was administered to 150 children, ages 3 to 8 yr. The internal consistency was very high for each subtest. Significant correlations were obtained among the subtests. Significant differences in scores were noted for the three age groups, indicating the need for standards at each age group. Preliminary Z-scores and percentile ranks were computed for each age group. It was concluded that the inventory is a valuable, reliable tool of lipreading evaluation in children.

Child↗
PubMed1992

Revised Craig Lipreading Inventory.

The two purposes of this study were to shorten the Craig Lipreading Inventory without affecting its reliability and validity and to establish normative data on the revised version. The full inventory was administered to 75 children. By item analysis, half of the items were selected to comprise the brief version; both versions were administered to another group of 75 children. Scores on the two versions correlated (.91 and .92, respectively, for Word Forms A and B and .97 and .95, respectively, for Sentence Forms A and B), thereby substantiating the construct validity of the briefer version. There was significantly high intertest reliability for the Word Forms (.80) and Sentence Forms (.82) of the briefer inventory. Normative data were computed for each age group. This briefer version is a temporally efficient tool for evaluating lipreading ability of children.

Aptitude↗
PubMed1989

Effect of encouragement on performance of young and old subjects on a task involving lipreading.

Two tests of lipreading ability were constructed, one using numbers and the other of sentences including visual cues. The tests were given to two groups of men, one older group aged 40 yr. and over (n = 110) and a younger group of less than 40 yr. (n = 70). Requests to guess produced a higher mean score for the older subjects on the lipreading tests containing the greater amount of information. It is suggested that differences in the effect of encouragement on performance between young and old may be related to both age and cultural factors.

Adult↗
PubMed1996

Lipreading with auditory low-frequency information. Contextual constraints.

The present experimental study investigated potential relations among three variables: (1) an audiovisual speech signal (i.e., low-frequency supplemented lipreading as opposed to pure lipreading), (2) typical, as opposed to atypical, sentences in a particular script (e.g., in a restaurant), and (3) the presence/absence of additional context (in the particular script) in 60 normal hearing subjects. All three variables revealed significant main effects, but no interactions were observed. The general facilitatory effect for the audiovisual signal is in line with previous research, but this effect was relatively weak compared to the main effect of typicality, which relies on cognitive activation of scripts. In a separate analysis, the typicality variable was also the only variable that interacted significantly with speechreading skill, typical sentences being perceived relatively easier by the skilled as opposed to the less skilled individual. The clinical implications of cognitive factors in hearing-aid fitting procedures, the construction of speech materials, and selection of individuals for rehabilitation were discussed.

Humans↗
PubMed1991

Similarity ratings and confusability of lipread consonants compared with similarity ratings of auditory and orthographic stimuli.

Similarity ratings of pairs of lipread consonants were obtained using a 5-point scale. Matrices were constructed showing mean similarity ratings and confusions among stimuli. Both the similarity and the confusion data provide normative data useful for researchers in many areas. Lipread data collected here are compared with similarity ratings of orthographically and auditorily presented consonants collected by Manning (1977). These comparisons provide information about how stimulus similarity both within and between presentation formats may affect information processing of the three types of stimuli. These data are of special interest to researchers studying the visual processing of speech and the effect of format of presentation on recall.

Adult↗
PubMed1993

Auditory pattern perception in the profoundly hearing impaired and lipreading of Dutch phonemes.

Successful rehabilitation of the profoundly hearing impaired by means of a speech-processing hearing aid requires integration of auditory and visual speech information. In two studies we investigated (1) which perceptual dimensions play a role in processing various auditory patterns by profoundly hearing-impaired subjects, and (2) which Dutch consonants and vowels can be identified by the average lipreader. One of the important cues in auditory pattern discrimination seems to be the presence of temporal fluctuations (beats) in the signal, resulting from two closely placed frequency components. However, this feature is confounded with the perception of loudness. A second cue used by some subjects is the presence of high-frequency peaks. In lipreading, at least three groups of consonants and three vowel groups may be distinguished; phonemes within a group cannot be discriminated from each other. Important features for both consonants and vowels are degree of lip opening and lip activity (movement or rounding). These results suggest how the auditory speech signal might be coded so as to provide supplementary information to speechreading.

Acoustic Stimulation↗
PubMed1983

Further evidence of interference between lipreading and auditory recency.

In both free and backward recall, it is shown that auditory but not visual recency is greatly disrupted when subjects have to lipread, rather than read, a series of numbers in a distractor task interpolated between list presentation and recall. This selective interference effect extends the generality of a finding reported by Spoehr and Corin (1978) and adds to an accumulating body of evidence that seems inconsistent with acoustic or echoic memory interpretations of the enhanced recency recall typically observed in comparing auditory with visual presentation. Alternative interpretations are briefly considered.

Humans↗
PubMed1989

Speech perception studies using a multichannel electrotactile speech processor, residual hearing, and lipreading.

Three studies are reported on the speech perception of normally hearing and hearing-impaired adults using combinations of visual, auditory, and tactile input. In study 1, mean scores for four normally hearing subjects showed that addition of tactile information, provided through the multichannel electrotactile speech processor, to either audition alone (300-Hz low-pass-filtered speech) or lipreading plus audition resulted in significant improvements in phoneme and word discrimination scores. Information transmission analyses demonstrated the effectiveness of the tactile aid in providing cues to duration, F1 and F2 features for vowels, and manner of articulation features for consonants, especially features requiring detection and discrimination of high-frequency information. In study 2, six different cutoff frequencies were used for a low-pass-filtered auditory signal. Mean scores for vowel and consonant identification were significantly higher with the addition of tactile input to audition alone at each cutoff frequency up to 1500 Hz. The mean speechtracking rate was also significantly increased by the additional tactile input up to 1500 Hz. Study 3 examined speech discrimination of three hearing-impaired adults. Additional information available through the tactile aid was shown to improve speech discrimination scores; however, the degree of increase was inversely related to the level of residual hearing. Results indicate that the electrotactile aid may be useful for patients with little residual hearing and for the severely to profoundly hearing impaired, who could benefit from the high-frequency information presented through the tactile modality, but unavailable through hearing aids.

Adult↗
PubMed1997

Activation of auditory cortex during silent lipreading.

Watching a speaker's lips during face-to-face conversation (lipreading) markedly improves speech perception, particularly in noisy conditions. With functional magnetic resonance imaging it was found that these linguistic visual cues are sufficient to activate auditory cortex in normal hearing individuals in the absence of auditory speech sounds. Two further experiments suggest that these auditory cortical areas are not engaged when an individual is viewing nonlinguistic facial movements but appear to be activated by silent meaningless speechlike movements (pseudospeech). This supports psycholinguistic evidence that seen speech influences the perception of heard speech at a prelexical stage.

Auditory Cortex↗
PubMed1987

The assessment of lipreading ability: some practical considerations in the use of the tracking procedure.

Continuous discourse tracking is potentially a very useful clinical technique and the practical difficulties it may present to the inexperienced user can readily be overcome. Some modifications to the traditional scoring procedure are described to provide a measure of fluency in addition to the basic word per minute score. Suggestions are offered regarding the practical management of the timing and the choice and preparation of the text. The procedure is discussed in the context of evaluating different augmentative approaches to lipreading for individual patients.

Attention↗
PubMed1993

Automatic lipreading.

We have implemented an automatic visual lipreading system intended to supplement a standard automatic speech recognizer. The system extracts a small set of parameters from a video image sequence. These include geometrical and local brightness information about the images. Standard ASR techniques are applied to the data. Performance is tested on a small task of discriminating 22 consonants, with and without added white noise. The visual system alone achieves approximately 47% accuracy. More importantly, however, when it is used in conjunction with an audio-based speech recognizer, the performance of the combined system exceeds that of either system used alone. This effect is more pronounced when white noise is added to the audio signal, and can result in as much as a 61% error reduction depending on the noise level.

Algorithms↗