Speech Disruption Research Articles

Physiological factors related to delayed auditory feedback and stuttering: a review.

Delayed auditory feedback (DAF) generally produces speech disturbances in normal speakers and improved fluency in stutterers. Several theorists have proposed that the speech disruptions of normal persons under such delayed feedback are an analog of stuttering. Related research has linked delayed auditory feedback and stuttering to several physiological factors. A review of familial relationship, age, sex, stress, speech characteristics, and sound conduction is presented. A brief integration of the factors and directions for research is presented.

Intrapair similarity in frequency of disfluency in monozygotic and dizygotic twin pairs containing stutterers.

It is known that concordance for stuttering is higher in monozygotic (MZ) than in dizygotic (DZ) twins. Evidence for genetic contribution to the frequency of speech disruption in stutterers was examined in 17 pairs of MZ and 13 pairs of DZ twins, each pair containing at least one stutterer. Intraclass correlations and analyses of variance indicated positive evidence for a genetic contribution to the overall frequency of disfluency in speech and to the frequency of certain types of speech disruption (blocked and prolonged sounds). There was little evidence for genetic influence on other types of speech disruption (various types of repetitions and interjections) In those disfluency types for which genetic predictions were confirmed, evidence of excessive dissimilarity in DZ cotwins suggests that a simple, additive gene-environment model is unlikely to be appropriate for disfluency frequency data.

How school-aged students define stuttering and stammering

Fifty students from each of the grades 2, 4, 6, 8, 10, and 12 were asked to complete a questionnaire containing the following three questions: 1) What is stuttering? 2) What is stammering? 3) How did you know that? Analysis of their responses indicated students were more familiar with stuttering as opposed to the term stammering. From grade 6 onward, we can expect at least three-fourths of the students to define stuttering as a disruption of speech consisting chiefly of sound or syllable repetitions. Only about one-fourth of students in grade 6 and above defined stammering as a speech disruption. This disruption was characterized chiefly by repetitions, injections, and pauses. Most of the students were unable to specify how they learned the definitions. The few who did identified family and friends as their chief source of knowledge.

The effects of presentation of noise and dental appliances on speech.

The effects of dental appliances on speech were studied when subjects wore the appliances, both in quiet and in the presence of an intense noise. A group of 24 normal-speaking subjects read lists of syllables, words, and sentences and spoke spontaneously in each of six appliance and noise conditions. Several acoustic and perceptual measurements were made in each condition. In general, speech deteriorated when appliances were placed and when noise was presented. The type and amount of speech disruption varied as a function of speech task and aspect of speech. There was no evidence that the effects of appliances on speech differed in quiet and noise conditions. Inter-subject variability was large.

Effects of stress and retesting on role play tests of social skill

The purpose of this study was to examine the role of stress in performance on role play tests of social skill. Chronic psychiatric patients were tested in a formal videotape studio or in an informal consulting room setting. Motoric and physiological measures were secured. In addition, one-half of the subjects were retested one week later. In contrast to previous studies, results indicated that the assessment was not stressful. The two groups were not different on any measure, and the mean heart rates ranged from only 80 to 84 b.p.m. The effects of retesting were difficult to interpret. There were reductions in motoric indices of anxiety (speech disruptions) but not on physiological indices. Overall, testretest reliability was quite high. The results raise several questions which affect interpretation of many social skills studies in the literature.

The relevance of DAF-induced speech disruption to the understanding of stuttering

Abstract The literature on delayed auditory feedback (DAF) repeatedly makes reference to the occurence of disfluencies under DAF in nonstutterers. However, no attempt has been made to determine the relative frequency of occurence of various types of disfluencies in nonstutterers under DAF. The present study investigated the frequency of occurence of various types of disfluencies in normal-speaking subjects in five successive oral readings under DAF. Twenty-four young adults read aloud a prose passage five times successively under 200 msec of bilateral DAF. Measures of the frequency of different types of disfluencies, locus of occurence of disfluencies in the speech sample, adaptation and consistency indicate that DAF-induced disfluencies are remarkably similar to those found in stuttering. It is suggested that DAF and stuttering disrupt speech at approximately the same “level” along the speech production process, possibly at the prosodic level.

Social Class, Sex and Linguistic Coding

It was hypothesized that specific styles of linguistic coding would be evident along the dimensions of both social class and sex. Individual structured interviews were undertaken with 96 sixteen-year-olds, divided into equal social class/sex groups. The verbatim transcripts were examined along selected aspects of linguistic coding: structure, elaboration, prepositional and pronominal usage, and speech disruptions. Discriminant function analysis, extended and supplemented by analysis of variance, was used to test the hypothesis of differential coding patterns for the social class/sex groups. The discriminant analysis showed that the 28 linguistic variables, in combination, distinctly separated the social classes on Discriminant Function I and that Discriminant Function II separated the groups in terms of the sex dimension.

Planning units and syntax in sentence production

The study was conducted to determine, first, whether it is the deep or the surface clause that is more important as a speech planning unit, and second, whether syntactic decisions are made during sentence production. Subjects, while talking, heard tones to which they had to respond by pressing a button; reaction times to these tones were taken as an index of processing load during production. It was found that there were increased RTs at the ends compared with the beginnings of deep structure clauses. No difference was found between RTs at the beginnings and ends of surface clauses not corresponding to a deep clause. The results were interpreted as showing that deep clauses are major planning units and that some planning for clauses occurs at the end of the preceding clause. Differences were found between RTs during clauses of different syntactic structure. These results were interpreted as indicating that syntax influences production and were discussed in relation to previous studies of pausing and speech disruption.

Discomforting talk and speech disruptions.

Discomforting talk and speech disruptions.

Discomforting talk and speech disruptions.

Discomforting talk and speech disruptions.

Perceptual and Acoustical Effects of Oral Anesthetization on the Speech of Young Children

Speech samples of four normal-hearing and -speaking children aged 2.6, 3.7, 5.0, and 9.3 were recorded prior to and during oral anesthetization. Phonetic and acoustical analysis of the speech samples were made. The speech of all the children remained intelligible; however, anesthetization produced slightly more perceptual disruption of the younger children's speech than the older. The nature of disruptions were for the most part consistent with those reported for adults by Scott and Ringel [J. Speech Hearing Res. 14 (1971)]. Acoustical analysis revealed temporal as well as spectral changes in the speech signals of all children during anesthetization. The acoustical changes which occured, however, were more variable for the younger children than for the older children. These results are discussed in terms of open- and closed-loop models for the acquisition and subsequent control of the articulatory gestures of speech.

Production of complex sentences in monologues and dialogues

This study asks whether the speaker makes decisions about syntax in the construction of complex sentences (those containing at least one subordinate clause). The speaker's disruptions, for example, filled pauses and tongue slips, are taken as clues to his decision making. Results show that in monologues, speech disruptions are not correlated with sentence complexity (number of subordinate clauses) when sentence length is constant. However, in both monologues and dialogues, a particular syntactic distinction has relevance for performance, that is, noun phrase complement constructions are more likely to be disrupted than sentences containing relative clauses. It is concluded that syntactical and situational context are factors in the speaker's production decisions.

Effects of delayed auditory feedback on children with disorders in auditory processing

A comparison was made of the effects of delayed auditory feedback (DAF) on the speech of children with known auditory processing dysfunction and on the speech of children with no such auditory problems. Eight boys with auditory deficiencies were matched for age with eight boys whose auditory abilities were normal. Subjects performed under four DAF and four synchronous feedback conditions. Tape recordings were analyzed by three judges for duration, frequency of speech disruptions, and percentage of correct words. Although the speech of both groups was significantly affected by DAF, no significant differences between the groups were observed. Those experimental subjects with poor contextual speech showed a significantly greater number of speech disruptions and a significantly smaller percentage of correct words under DAF than did those experimental subjects with better contextual speech. The two groups tended to prolong sounds in words more than they repeated of omitted sounds in words. Both groups had more omissions and prolongations during serial speech than during recitation. The control subjects showed more repetitions during recitation than during serial speech. Both groups showed a tendency toward an adaptation effect for repetitions.

Speech intelligibility in the presence of time-varying aircraft noise.

This study concerns the question of whether or not the relation between intelligibility test scores and the Articulation Index (AI) established for steady-state noise can be used to predict speech intelligibility in the presence of time-varying aircraft noise. For various aircraft flyovers, intelligibility scores and several noise measures were obtained as functions of time. In addition, intelligibility scores and measures of AI were obtained for steady-state simulated aircraft noise. The relation between speech intelligibility and AI for time-varying noise was different from the relation obtained for steady-state noise. The various noise measures were almost equally effective in predicting speech intelligibility in the presence of time-varying aircraft noise. There is an appreciable disruption of contextual speech when the peak level of a flyover exceeds 88 PNdB, a speech-interference level of 68 dB, or an A-weighted sound-pressure level of 76 dB.

Speech Intelligibility in the Presence of Time-Varying Aircraft Noise

There has been some question as to whether the relationship between the articulation index (AI) and intelligibility test scores established for steady-state noise can be used to predict intelligibility scores that would be obtained in the presence of time-varying aircraft noise. For various aircraft flyovers, speech intelligibility scores and various noise measurements were obtained as functions of time. In addition, intelligibility scores and measures of AI were obtained for steady-state simulated aircraft noise. The relation between AI and speech intelligibility for flyover noise was different from the relation obtained for the steady-state noise. The various noise measures were almost equally effective in predicting speech intelligibility in the presence of flyover noise. There is an appreciable disruption of contextual speech when the peak level of a flyover exceeds 88 PNdB, an SIL of 68 dB, and an A-weighted sound-pressure level of 76 dB. [Work supported by Federal Aviation Administration.]

Interjudge Reliability for Formal Aspects of Interviewee Communication

The reliability among two Master's level clinical psychologists and two Master's level psychiatric social workers in judgment of frequency and location of 8 types of speech disruptions, periodic judgments of speech rate, and location of change in speech rate was determined from interviewees' responses in four taped interviews. With the exception of the “ah” type of disruption, reliability estimates were quite low. The utility of clinical observation of these non-verbal behaviors was questioned when reported by clinicians not specifically and extensively trained for observation of these signs. A suggestion was made regarding the direction for development of training procedures.

Age and Sex Differences in Speech under Delayed Auditory Feedback

A developmental study of speech under delayed auditory feedback (DAF) indicated that: (1) the delay in auditory feedback producing maximal disruption of speech varied significantly with the age of the speaker. The delay in auditory feedback producing maximal speech disruption was 0.60 sec for children aged 4–6; 0.6 sec. for children aged 7–9; 0.2 sec for children aged 10–12; 0.2 sec for adults aged 20–26; and 0.4 sec for adults aged 60–81; (2) children aged 4 to 6 were more affected by DAF than adults, regardless of the delay condition; (3) the delay that produced maximal speech disruption did not become shorter with the increasing age of the subject, thus altering a conclusion reached by MacKay [D. G. MacKay, J. Acoust. Soc. Amer. 43, 811–821 (1968)]; (4) the critical interval of delay, which produced maximal disruption of speech, did not vary significantly for males and females within a given age group; (5) a subject's maximum rate of speech correlated significantly with the amount of stuttering produced under DAF. The slower a subject's maximum rate of speech, the more he tended to stutter under DAF.

Metamorphosis of a critical interval: age-linked changes in the delay in auditory feedback that produces maximal disruption of speech.

A developmental study of delayed auditory feedback (DAF) indicated that: (1) DAF disrupts the speech of children more than adults, for all delays in feedback; (2) The delay for maximal interference varies with age. The older a subject, the shorter the delay producing maximal interference with his speech; (3) The peak interference delay remains at 0.2 sec, when adults reduce their rate of speech by drawing out speech sounds. This finding suggested that the critical DAF interval is independent of the duration of speech sounds in the returning auditory signal; (4) Slowing down the rate of speech as described above, reduced the amount of stuttering under DAF; (5) However, a subject's maximum rate of speech was significantly correlated with the duration of the delay producing maximal interference with his speech. The slower the subject's maximum rate of speech, the longer the peak interference delay. A correlation of maximum speech rate and frequency of DAF stuttering was also significant. The slower a subject's maximum speech rate, the more he tended to stutter under DAF. Since voluntary prolongation of speech sounds had the opposite effect, decreasing rather than increasing stuttering, it was suggested that: (l) Mechanisms determining the maximum speech rate are to some extent different from those governing the prolongation of speech sounds; (2) both the amount of stuttering under DAF and the peak interference delay are related to some as yet unknown factor or set of factors determining the maximum rate of speech, and, (3) this factor is age-linked since the maximum rate of speech varies inversely with age.

Anxiety and temporal perspective among normals in a stressful life situation.

The present study examines relationships between specific types of speech disruption denoting anxiety (the “non-ah” ratio; Mahl, 1959) and tense usage among normal Ss as they experience a real-life stress situation. Major findings are low positive correlations between anxiety and present tense ( r = .38, p < .05) and between anxiety and present plus future tense ( r = .43, p < .05). Since statistical controls (partial correlation) indicate that these relationships are independent of verbal productivity, it appears likely chat normal Ss respond to stress by emphasizing present time. It is tentatively suggested that this behavior may serve a coping or problem-solving function.

Predictability and Disruption of Spontaneous Speech

Three experiments were conducted to test the general hypothesis that disrupted spontaneous speech is less predictable than fluent speech. Predictability was estimated by means of the Cloze procedure and disruption by Mahl's non- ah speech disturbance ratio. The hypothesis was not confirmed. Instead, the results revealed significant differences in predictability among speakers and as a function of the degree of verbal interaction and topical focus of the speech. Moreover, the effect of the latter conditions also varied from speaker to speaker. A significant interaction occurred such that the speech of certain speakers was more predictable when it was highly disrupted, while that of others was less predictable when highly disrupted.