Stammering research : an on-line journal published by the British Stammering Association最新文献

Many of the statistical issues involved in speech and hearing research are shared with other areas of medicine. This article is the first in a series intended to stimulate examination of research data in speech and hearing areas using a wide variety of techniques. This article specifically deals with two essential, but elementary, issues. The first is concerned with experimental design and choice of test data. The second, defines and explains statistical terms, concentrating particularly on the inference to the population mean from the sample mean.

This article provides a brief introduction to the history and applications of the class of data analytic techniques collectively known as Structural Equation Modeling (SEM). Using an example based on psychological factors thought to affect the likelihood of stuttering, we discuss the issues of specification, identification, and model fit and modification in SEM. We also address points relating to model specification strategies, item parceling, advanced modeling, and suggestions for reporting SEM analyses. It is noted that SEM techniques can contribute to the elucidation of the developmental pathways that lead to stuttering.

Conventional clinical procedures for assessment of stuttering are reported to have poor reliability. Time interval analysis procedures have been reported to produce greater reliability than the conventional procedures. In time interval procedures, successive intervals of the same duration are extracted from a sample of speech and judged by participants as stuttered or fluent. There is a problem insofar as the amount of speech judged stuttered depends on the length of the interval used. This problem is illustrated in an experiment in which 1-s and 5-s intervals were drawn from the same samples of speech and judged by participants as stuttered or fluent. It is also shown that the problem of lack of sensitivity when longer intervals are used is more acute for individuals who exhibit severe stuttering. Since ability to detect changes in stuttering rate is dependent on the length of interval used (as well as stuttering severity), the procedure can highlight or disguise changes in stuttering rate depending on parameterization of interval length and choice of participants to study. Thus, use of different length intervals across studies can distort whether particular treatments have an effect on speech control. Therefore, it is concluded that time interval analysis, as it is currently used, is an unsatisfactory procedure. If a standard-length interval could be agreed, comparison across studies or analyses would be possible.

This paper investigates whether stuttering rates in English-speaking adults and children are influenced by phonological and morphological complexity at the ends of words. The phonology of English inflection is such that morphological and phonological complexity are confounded, and previous research has indicated that phonological complexity influences stuttering. Section 1 of this paper considers how to disentangle phonological and morphological complexity so that the impact of each on stuttering can be tested. Section 2 presents an analysis of some adult corpus data, and shows that phonological and morphological complexity at the word end do not influence stuttering rates for English-speaking adults, at least in spontaneous speech. Section 3 presents results from a non-word repetition task and a past tense elicitation task which reveal that while word-end phonological and morphological complexity do not affect stuttering rates in most of the adults and children tested, a small proportion of adults and children do stutter over morphologically complex words in an elicitation task. Taken as a whole, these results suggest that morphology has an impact on stuttering for some individuals in certain circumstances.

Frequency shifted feedback (FSF) induces fluency when presented to speakers who stutter. This study examined whether FSF was more effective at removing disfluencies on easy or on difficult stretches of speech (where difficulty was defined with respect to utterance and word length). There were more disfluencies on the difficult stretches than on the easy stretches. There were significantly fewer disfluencies under FSF than in normal listening conditions (indicating that FSF improved fluency). There was no interaction between difficulty of material and type of feedback when disfluency rate was used as the dependent variable, suggesting that targeting FSF on easy stretches of speech is as effective as targeting it on difficult stretches. The original audio data are provided in this report and can be used by readers to check for themselves the characteristics of voice control that alter when FSF is delivered.

Most models that explain the onset and development of stuttering include a social and emotional component. This paper has two intentions. One is to review the methods and findings of previous research that investigated the role of affective and social factors in stuttering. The second intention is to alert readers to various methods and issues being applied in social psychology to investigate these phenomena and to indicate where these methods could be useful in assessing the role of social and affective components in stuttering.

The purpose of this article is to indicate how access can be obtained, through Stammering Research, to audio recordings and transcriptions of spontaneous speech data from speakers who stammer. Selections of the first author's data are available in several formats. We describe where to obtain free software for manipulation and analysis of the data in their respective formats. Papers reporting analyses of these data are invited as submissions to this section of Stammering Research. It is intended that subsequent analyses that employ these data will be published in Stammering Research on an on-going basis. Plans are outlined to provide similar data from young speakers (ones developing fluently and ones who stammer), follow-up data from speakers who stammer, data from speakers who stammer who do not speak English and from speakers who have other speech disorders, for comparison, all through the pages of Stammering Research. The invitation is extended to those promulgating evidence-based practice approaches (see the Journal of Fluency Disorders, volume 28, number 4 which is a special issue devoted to this topic) and anyone with other interesting data related to stammering to prepare them in a form that can be made accessible to others via Stammering Research.

The usage-based approach to language development suggests that children initially build up their language through very concrete constructions based around individual words or frames on the basis of the speech they hear and use. These constructions gradually become more general and more abstract during the third and fourth year of life. We outline this approach and suggest that it may be applied to problems of fluency control in early child language development.

It has been known for at least a hundred years that the speech of a person who stammers becomes more fluent when alterations are made to the speaking environment. Alterations that lead to an improvement in fluency include a) noises that prevent a speaker hearing his or her own voice, and b) manipulations to the sound of a speaker's voice before it is heard. Examples of manipulations that have been made are introducing a delay, and shifting the voice up or down in frequency. The influences all these alterations have on fluent speakers and speakers who stammer, that have been established over the last century, are reviewed. In addition, the ways in which these phenomena have been explained for both fluent speaker and speakers who stammer are outlined. Several previous findings have potential significance for ways in which the fluency-enhancing effects of these alterations in speakers who stammer could be employed in clinical settings. These are highlighted and discussed, mainly in connection with the SpeechEasy prosthetic device for treating stammering.