A longitudinal study of articulation, language, rate, and fluency of 22 preschool children who stutter

Abstract

This is a longitudinal study of the speech and language characteristics of 22 preschool-age stuttering children, 16 from Ryan [J. Speech Hear. Res. 35 (1992) 333.]. They were tested approximately quarterly, eight times over a 2-year period. None received treatment during the first year. All of the children demonstrated improvement in articulation and language and 68.2% recovered from the stuttering without treatment. There were no significant differences in articulation and language test scores between those who recovered and those who persisted, nor any significant correlations between articulation and language tests and stuttering. Of the variables studied, the trend in repeated measures of stuttering over time of individual children was predictive with 90.9% accuracy of recovery or persistence of stuttering. Educational objectives: (1) The learner will be able to describe the findings from repeated tests of articulation and language for groups of preschool-age children who recovered or persisted in stuttering. (2) The learner will be able to describe how trends in the frequency of stuttering over time may be used as a predictor of recovery or persistence. (3) The learner will be able to describe how longitudinal studies of preschool-age children provide important information on the natural course of stuttering.

Introduction

This is a longitudinal study of the speech and language proficiency of preschool-age children who stutter originally studied by Ryan (1992). Longitudinal studies offer a unique perspective on the development of stuttering Andrews & Harris, 1964, Johannsen, 1997, Johannsen & Schulze, 1995, Månsson, 2000, Ryan, 1984, Ryan, 1990, Ryan, 1998, Yairi, 1981, Yairi, 1982, Yairi, 1990, Yairi & Ambrose, 1992a, Yairi & Ambrose, 1992b, Yairi & Ambrose, 1999, Yairi et al., 1993, Yairi et al., 1996. The longitudinal research of this study is similar to that of Yairi et al. (1996) in age of children (2 to 5 years of age), observation over several years, repeated administration of speech and language tests, and objectives (e.g., to develop or discover predictive measures of spontaneous recovery or persistence of stuttering in preschool children by studying and comparing children who persist with those who recover) although this study differs in several important ways (e.g., sample size).

Bernstein Ratner (1997) and Nippold (1990) have provided excellent reviews of many cross-sectional studies of the speech and language skills of children who stutter, including some comparisons with nonstuttering children. The major findings so far have been that some children who stutter may have slightly reduced language proficiency when compared to controls (e.g., Ryan, 1992, Watkins & Yairi, 1997, Watkins et al., 1999, Yairi et al., 1996) and that more complex linguistic utterances are more often stuttered Bernstein Ratner & Sih, 1987, Gaines et al., 1991, Logan & Conture, 1995, Ryan, 2000c.

It is generally agreed that the incidence of articulation/phonological deficits in children who stutter is relatively high Blood & Seider, 1981, Bloodstein, 1995, Louko et al., 1990, Nippold, 1990, Paden et al., 1999, Ryan, 1992, St. Louis & Hinzman, 1988, Williams & Silverman, 1968, Wolk et al., 1993, Yaruss et al., 1998, although Ryan (1992) found no significant differences in articulation test scores of stuttering and nonstuttering children. Throneburg, Yairi, and Paden (1994) observed that stutterings were not due to the phonological difficulty of disfluent words or of words that followed them. Paden and Yairi (1996) and Yairi et al. (1996) stated that although preschool children who stutter may initially show more phonological problems than do nonstuttering controls, those who recover do not differ in phonological ability from those who persist, but their discriminant analysis did include phonological proficiency. Beyond the oft-reported cooccurrence of articulation or phonological processing problems in children who stutter (e.g., 37.4%, Yaruss et al., 1998) little is known about the bases of this association Paden & Yairi, 1996, Paden et al., 1999.

Using age-adjusted scoring, Paden et al. (1999) found that children with persistent stuttering scored worse than did recovered children in five of six age-group comparisons of phonological process analyses. Other findings included: (a) there were more children with moderate and severe phonological process errors in the persistent group, (b) the two groups did not differ from normally developing children in their path of development, and (c) the percentage of errors on phonological patterns was not predictive of recovery or persistence. Paden et al. (p. 1113) concluded that, “The results indicate that the children whose stuttering would be persistent had poorer mean [phonological process] scores on each of our measures than did the children who would recover from stuttering.” These analyses were limited somewhat because sample size of the subgroups proscribed inferential statistical analysis. Although phonological process analysis might provide different results from articulation or phonetic analyses of children who stutter, both measures are related and might be expected to yield related, perhaps, similar results (Garett & Moran, 1992).

Yairi et al. (1996) observed that the 12 children who persisted in stuttering displayed lower language scores than did the 20 who recovered. Watkins and Yairi (1997) reported that only 1 out of the 32 children (3%) had a possible clinical language problem. A discriminant analysis employing phonological processing and language test findings correctly placed 81.3% of the children into either recovered or persistent groups. However, the mean lenghts of utterance, numbers of different words, and total words did not differ between those who recovered and those who persisted in stuttering. Watkins et al. (1999) studying expressive language in conversation found that language ability did not differentiate persistent from recovered children who stutter. Watkins and Yairi, Watkins et al., and Yairi et al. concluded that stuttering and language are related, but the nature of that relationship is not clear.

A number of studies of speaking rate and stuttering have reported findings from cross-sectional comparisons of stuttering and nonstuttering children (e.g., Kelly & Conture, 1992, Meyers & Freeman, 1985, Ryan, 1992, Ryan, 2000c) or case studies such as that reported by Guitar, Schaefer, Donahue-Kilburg, and Bond (1992) or Stephenson-Opsal and Ratner (1988). The major findings have been that there are (a) no significant differences in speaking rate between stuttering and nonstuttering preschool-age children and (b) few significant correlations between stuttering and speaking rate or between speaking rate and other linguistic variables Kelly & Conture, 1992, Ryan, 1992, Ryan, 2000c. One exception is the finding of Kloth, Janssen, Kraaiamaat, and Brutten (1995) who observed significantly higher articulation rates in a group of young preschool-age children who were stuttering a year later compared to the rates of those children who did not begin to stutter. Hall, Amir, and Yairi (1999) reported findings from three sets of measures obtained over 2 years from 24 children (eight recovered, eight persisted, and eight normally fluent), using two measures of articulation rate (syllables per second and phones per second). They found that the children who recovered spoke nonsignificantly slower, as measured by syllables per second, than the other group for three comparisons but that both stuttering groups spoke significantly slower than did the control group as measured by phones per second. The three groups combined had a significant increase in speaking rate over the 2 years of the study.

The major available information about the prediction concerning persistence of, or recovery from, stuttering is found in Yairi et al. (1996, p. 73) who concluded that generally “…(a) age at onset, (b) duration of the disorder, (c) family history of persistent and recovered stuttering, and (d) scores on language/nonverbal measures…” were promising predictors, especially age of onset and language proficiency as first reported by Yairi (1983). Sex was later added as a predictive factor with more females than males recovering from stuttering (e.g., Månsson, 2000, Watkins & Yairi, 1997, Yairi & Ambrose, 1999). Perhaps surprisingly, severity of stuttering has not held much predictive promise because many children have shown severe stuttering, only to naturally recover from the problem apparently without assistance Yairi & Ambrose, 1992a, Yairi & Ambrose, 1992b, although extremely severe stuttering may be a predictor of persistence Ryan, 1990, Ryan, 2000b. Little is known about the specific contributions of articulation or phonological processing and linguistic proficiency and speaking rate, nor the interaction among them, to the development of stuttering although past research suggests a relationship Paden & Yairi, 1996, Watkins & Yairi, 1997, Watkins et al., 1999.

The purposes of this study of 16 of the male and female preschool stuttering children from Ryan (1992) and 6 others were to: (a) describe their articulation, language, stuttering, and speaking rate development over a 2-year period; (b) identify any differences between the children with persistent stuttering and those who recovered; (c) study the interactions between and among these variables; and (d) identify variables that predict recovery from or persistence in stuttering.