38 research outputs found

    Investigating the effects of accent on visual speech

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    Speechreading is a complex skill affected by both the observer's method of extracting visual speech information and talker-specific variation in speech production. This thesis focuses upon accent, a factor that can influence both an observer's viewing strategy and talker speechreadability. Auditory research demonstrates that an unfamiliar accent reduces speech intelligibility. The primary aim here was to determine whether accent type, familiarity or variation would alter visual speech intelligibility with consequential effects upon speechreading performance. Experiments 1 and 2 considered visual discrimination of native and non-native accented speech and the influence of non-native accent upon speechreading performance. Results indicated that observers were able to utilise visual cues for discrimination and were significantly poorer at speechreading a non-native accent. Experiments 3, 4 and 5 examined the influence of regional accent on speechreading performance. Results indicated that visual speech performance was significantly worse for Glaswegian-accented talkers than for talkers with a Nottingham accent. However, no clear advantage for accent familiarity was found. Experiment 6 examined the influence of accent type and talker variability upon speechreading performance. Accent type was consistently the dominant influence upon speechreading performance, above familiarity and variation. Experiments 7, 8, 9 and 10 examined the influence of exposure, context and repetition upon the effects of a Glaswegian accent. Here, the effect of the Glaswegian accent on talker speechreadability was reduced by context and repetition, but not removed entirely. In conclusion, while visual accent type mostly determines visual speech intelligibility, accent familiarity mostly determines auditory speech perception. Although spoken accent effects can be quickly reduced through exposure, no such effect was found here in the visual modality. Both context and repetition were necessary to improve the intelligibility of accented speech. This indicates a potential difference in the processing of accented speech across the two modalities and has implications for speechreading training

    Investigating the effects of accent on visual speech

    Get PDF
    Speechreading is a complex skill affected by both the observer's method of extracting visual speech information and talker-specific variation in speech production. This thesis focuses upon accent, a factor that can influence both an observer's viewing strategy and talker speechreadability. Auditory research demonstrates that an unfamiliar accent reduces speech intelligibility. The primary aim here was to determine whether accent type, familiarity or variation would alter visual speech intelligibility with consequential effects upon speechreading performance. Experiments 1 and 2 considered visual discrimination of native and non-native accented speech and the influence of non-native accent upon speechreading performance. Results indicated that observers were able to utilise visual cues for discrimination and were significantly poorer at speechreading a non-native accent. Experiments 3, 4 and 5 examined the influence of regional accent on speechreading performance. Results indicated that visual speech performance was significantly worse for Glaswegian-accented talkers than for talkers with a Nottingham accent. However, no clear advantage for accent familiarity was found. Experiment 6 examined the influence of accent type and talker variability upon speechreading performance. Accent type was consistently the dominant influence upon speechreading performance, above familiarity and variation. Experiments 7, 8, 9 and 10 examined the influence of exposure, context and repetition upon the effects of a Glaswegian accent. Here, the effect of the Glaswegian accent on talker speechreadability was reduced by context and repetition, but not removed entirely. In conclusion, while visual accent type mostly determines visual speech intelligibility, accent familiarity mostly determines auditory speech perception. Although spoken accent effects can be quickly reduced through exposure, no such effect was found here in the visual modality. Both context and repetition were necessary to improve the intelligibility of accented speech. This indicates a potential difference in the processing of accented speech across the two modalities and has implications for speechreading training

    An Investigation of Speechreading in Profoundly Congenitally Deaf British Adults

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    Speechreading is the major route through which deaf people access the spoken language of the society in which they live. This thesis investigated speechreading and its correlates in a group of profoundly congenitally deaf British adults, and in a control group of hearing adults. For this purpose, the Test of Adult Speechreading (TAS) was developed. The TAS was designed to be sensitive to the perceptual abilities that underlie speechreading at varying linguistic levels, and to be appropriate, therefore, for use with d/Deaf as well as hearing individuals. The vocabulary and syntax used were selected to be familiar to Deaf adults, and the response mode, using picture choices only, made no demands on written or expressive spoken English. This new test was administered silently to groups of congenitally deaf and hearing adults, with a battery of visual, cognitive and language tasks. The deaf participants differed in their language and educational backgrounds, but all had hearing losses over 90dB. They significantly outperformed the hearing group on the TAS, even when only closely matched pairs of participants were included in the analyses. Adults who are deaf can speechread better than those who are hearing. Multiple factors impact on an individual’s speechreading abilities, and no single factor in isolation results in good speechreading skills. In addition to hearing status, other factors were identified through group comparisons, correlation and regression analyses, cluster analyses and multiple case studies, as being potentially necessary (although not sufficient) for skilled speechreading. These were lexical knowledge, the ability to visually identify sentence focus, and verbal working memory capacity. A range of further factors facilitated skilled speechreading, including hearing aid use, the use of speech at home during childhood, sensitivity to visual motion, personality (risk-taking & impulsiveness), and reading age. It seems there are many ways to become a skilled speechreader

    Effects of forensically-relevant facial concealment on acoustic and perceptual properties of consonants

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    This thesis offers a thorough investigation into the effects of forensically-relevant facial concealment on speech acoustics and perception. Specifically, it explores the extent to which selected acoustic-phonetic and auditory-perceptual properties of consonants are affected when the talker is wearing ‘facewear’ while speaking. In this context, the term ‘facewear’ refers to the various types of face-concealing garments and headgear that are worn by people in common daily communication situations; for work and leisure, or as an expression of religious, social and cultural affiliation (e.g. surgical masks, motorcycle helmets, ski and cycling masks, or full-face veils such as the niqāb). It also denotes the face or head coverings that are typically used as deliberate (visual) disguises during the commission of crimes and in situations of public disorder (e.g. balaclavas, hooded sweatshirts, or scarves). The present research centres on the question: does facewear influence the way that consonants are produced, transmitted, and perceived? To examine the effects of facewear on the acoustic speech signal, various intensity, spectral, and temporal properties of spoken English consonants were measured. It was found that facewear can considerably alter the acoustic-phonetic characteristics of consonants. This was likely to be the result of both deliberate and involuntary changes to the talker’s speech productions, and of sound energy absorption by the facewear material. The perceptual consequences of the acoustic modifications to speech were assessed by way of a consonant identification study and a talker discrimination study. The results of these studies showed that auditory-only and auditory-visual consonant intelligibility, as well as the discrimination of unfamiliar talkers, may be greatly compromised when the observer’s judgements are based on ‘facewear speech’. The findings reported in this thesis contribute to our understanding of how auditory and visual information interact during natural speech processing. Furthermore, the results have important practical implications for legal cases in which speech produced through facewear is of pivotal importance. Forensic speech scientists are therefore advised to take the possible effects of facewear on speech into account when interpreting the outcome of their acoustic and auditory analyses of evidential speech recordings, and when evaluating the reliability of earwitness testimony

    Change blindness: eradication of gestalt strategies

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    Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

    Semantic radical consistency and character transparency effects in Chinese: an ERP study

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    BACKGROUND: This event-related potential (ERP) study aims to investigate the representation and temporal dynamics of Chinese orthography-to-semantics mappings by simultaneously manipulating character transparency and semantic radical consistency. Character components, referred to as radicals, make up the building blocks used dur...postprin

    Language, perception and production in profoundly deaf children

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    Prelingually profoundly deaf children usually experience problems with language learning (Webster, 1986; Campbell, Burden & Wright, 1992). The acquisition of written language would be no problem for them if normal development of reading and writing was not dependent on spoken language (Pattison, 1986). However, such children cannot be viewed as a homogeneous group since some, the minority, do develop good linguistic skills. Group studies have identified several factors relating to language skills: hearing loss and level of loss, I.Q., intelligibility, lip-reading, use of phonology and memory capacity (Furth, 1966; Conrad, 1979; Trybus & Karchmer, 1977; Jensema, 1975; Baddeley, Papagno & Vallar, 1988; Baddeley & Wilson, 1988; Hanson, 1989; Lake, 1980; Daneman & Carpenter,1980). These various factors appear to be interrelated, with phonological awareness being implicated in most. So to understand behaviour, measures of all these factors must be obtained. The present study aimed to achieve this whilst investigating the prediction that performance success may be due to better use of phonological information. Because linguistic success for the deaf child is exceptional, a case study approach was taken to avoid obscuring subtle differences in performance. Subjects were screened to meet 6 research criteria: profound prelingual deafness, no other known handicap, English the first language in the home, at least average non-verbal IQ , reading age 7-9 years and inter-subject dissimilarities between chronological reading age discrepancies. Case histories were obtained from school records and home interviews. Six subjects with diverse linguistic skills were selected, four of which undertook all tests. Phonological awareness and development was assessed across several variables: immediate memory span, intelligibility, spelling, rhyme judgement, speech discrimination and production. There was considerable inter-subject performance difference. One boy's speech production was singled out for a more detailed analysis. Useful aided hearing and consistent contrastive speech appear to be implicated in other English language skills. It was concluded that for phonological awareness to develop, the deaf child must receive useful inputs from as many media as possible (e.g., vision, audition, articulation, sign and orthography). When input is biassed toward the more reliable modalities of audition and articulation, there is a greater possibility of a robust and useful phonology being derived and thus better access to the English language
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