Relationship between stuttering severity in children and their mothers ’ speaking rate Zahedan

Sao Paulo Med J. 2008;126(1):29-33. O R IG IN A L A R T IC L E Ali Dehqan


INTRODUCTION
Stuttering is described as a disorder of fluency and is characterized by part-word, whole-word and phrase repetitions, interjections, pauses and prolongations. 1 Perhaps no speech problem has received more attention than stuttering.A wide variety of theories have been proposed based on the enormous volume of research findings.Some theories have proposed physiological factors for the onset of stuttering, such as bilateral hemispheric dominance, 2 right hemispheric dominance for speech, 2,3 brain damage, 4,5 neuropsychological or neuromuscular dysfunction, 6 laryngeal dysfunction 7 and central auditory dysfunction. 8][18] Although the recent advances in imaging techniques have shifted attention to neurological and/or physiological factors for the onset or cause of stuttering, 19,20 the communication environment that stutterers live in may contribute towards maintaining the stuttering.Moreover, this communication environment that stuttering children live in may even play an important role in the success or failure of speech therapy.][23][24][25] Clinical intervention strategies currently used for children who stutter also frequently focus on the parents' role, instructing them to alter their linguistic behavior (e.g. by reducing negative statements regarding their child's speech and/or stuttering) and their paralinguistic behavior (e.g. by reducing their overall speech rate). 24,26- 37For example, Guitar and Marchinkoski 38 and others 39 reported that reductions in mothers' speaking rates resulted in similar reductions in children's speaking rates and corresponding improvements in speech fluency for some children who stuttered.
Past studies have observed parents from a unidirectional perspective.Research questions have centered on the idea that the parents of stutterers were different from the parents of nonstutterers.To conduct bidirectional research, Meyers and Freeman 40 explored the notion that the parents of children who stutter are "habitually fast talkers" and reported that the mothers of children who stutter spoke significantly faster than the mothers of nonstutterers did.Based on samples of the 15 longest perceptibly fluent utterances produced by each child, Meyers and Freeman 40 also found that the stuttering children spoke significantly more slowly during their fluent speech than did their nonstuttering peers, and that the children with severe stuttering talked more slowly than did the children with moderately severe stuttering. 40t has been hypothesized that alterations in parental speaking rates may influence the speaking rates of children who stutter. 21,22,40,41Guitar and Marchinkoski 38 investigated the effects on children's speech rate when their mothers talked more slowly and reported that when mothers substantially decreased their speech rates in a controlled situation, their children also decreased their speech rates. 38

OBJECTIVE
The aim of this study was to correlate the stuttering severity index with the speaking rates of mothers and their children who stutter.

Subjects: 35 pairs of mothers and their children who stuttered took part in this
study.There were 29 boys and 6 girls, and their mean age was 8.5 years (range 5.1-12.0years).The participants in this study were selected from the child rehabilitation clinics of Tehran University of Medical Sciences, in the city of Tehran.The selection criterion for the mothers of these children was that they should have normal speech, as diagnosed by a speech-language pathologist.The criterion for the children was that none of them had been evaluated for any fluency disorder or had received stuttering therapy prior to this study.Children who exhibited any clinically significant hearing, articulation, voice, language, psychological/emotional or physical problems that were considered atypical for their chronological age and level of development were excluded from this study.
Following data collection, a further assessment of stuttering was conducted by two certi-fied speech-language pathologists.Children were classified as stutterers if they exhibited three or more within-word dysfluencies (i.e.sound prolongations, sound/syllable repetitions, monosyllabic whole-word repetitions or broken words) per 100 words during a 300-word sample of audiotaped conversation with their mothers, and if people in their environments had expressed concern regarding their speech fluency.
Procedure: Each child and his/her mother were seated facing each other at a small table on which a series of action pictures had been placed.They were instructed to talk about these action pictures.Each mother-child pair was audiotaped for approximately 15 minutes, or until a sufficient sample from the child was obtained.All mother-child verbal interactions were audiotaped.
Following the recording session, the utterances produced by each mother-child pair, i.e. the "unit(s) of language preceded and followed by a perceived pause or termi-nated by some change in inflection (rising or falling intonation)", 42 were orthographically transcribed by the first author.A 10-minute warm-up period of audiotaping was conducted prior to data collection, during which the subjects had the opportunity to become familiar with the equipment and materials present in the test environment.The number of syllables per utterance spoken by the mother and child was included on the transcript.The location and type of each within-word and between-word (i.e.multisyllabic whole-word repetition, phrase repetition, revision or interjection) speech dysfluency produced by each mother and child was also indicated.Finally, two examiners checked the transcriptions.
The speaking rate in the present study was equivalent to articulatory rate, which is defined as a number of syllables (AR-S) produced per minute of nonstuttered speech. 41,43he stuttering severity was determined by means of an international instrument (the Stuttering Severity instrument).This test assesses the frequency and duration of speech disruptions, and also the presence of physical concomitants associated with these disruptions. 44The children who stuttered were divided into three groups based on their stuttering severity: 12 subjects were in the mild group, 15 in the moderate group and eight in the severe group.
Data analysis: One-way analysis of variance (ANOVA) was performed to compare the mothers' speaking rates and their children's stuttering severity and also to compare the children's speaking rates and their stuttering severity.The Pearson correlation was used to compare the speaking rates of the mothers and their stuttering children.The SPSS software (version 12) was used for data analysis.

RESULTS
As illustrated in Table 1 and Figure 1, there was a significant relationship between the means for the mothers' speaking rates and their children's stuttering severity.In other words, faster speaking rates among mothers were associated with greater stuttering severity in their children (p < 0.01).
On the other hand, as shown in Table 2, there was a significant negative correlation between the means for the mothers' speaking rates and their children's speaking rates (p < 0.01).Thus, the faster the mother's speaking rate was, the slower her child's speaking rate was.
Finally, Table 3 and Figure 2 present an intragroup comparison between the

Syllables per minute
Severity index children's speaking rates and their stuttering severity.This showed a significant correlation (p < 0.01) such that increased stuttering severity was associated with decreased speaking rates among the children who stuttered.In other words, the children with severe stuttering severity had a slower speaking rate than the moderate group did, and the moderate group had a slower speaking rate than the mild group did.

DISCUSSION
Despite the behavioral complexity of a stuttering problem, dysfluency often plays a primary role in differential diagnostic decisions and treatment evaluations.It is known that absolute continuity of speech production is physiologically impossible.A perception of continuous speech can be obtained from the number of audible speech utterances and the shortness of the physiological pauses (e.g.intervals for swallowing and breathing), and from the linguistic pauses (e.g.memory effects and lexical access) that are pertinent and expected from any speaker. 45The present study regarded the mother's speaking model as an important part of her child's interaction environment, which had an impact on the child's speaking model and was associated with the severity of the problem.This basic result held true in the present study, such that with increased speaking rates among the mothers with stuttering children, their children's stuttering severity would also be increased.
As was noted in the present study, the mothers with high speaking rates imposed more time pressure and communication stress on their small conversation partners.Thus, their children felt under more stress, which would result in enhancement of their stuttering severity.
On the other hand, enhancement of the children's stuttering severity would lead their mothers to get into a "nervous state" and they would compensate for this by increasing their speaking rates, in the hope that their children might increase their speaking rates.
Another result obtained from the present study was that, with increasing stuttering severity among these children, their speaking rate decreased.This result is also in line with the findings of Meyers and Freeman. 40Furthermore, the results from de Andrade et al. 45 and from the present study have confirmed the findings previously published regarding speakers of American English, thereby pointing to-wards a direct relationship between increases in the stuttering severity index and reductions in speech rate. 45he latter result, showing that there is an interesting negative correlation between mother's and children's speaking rates, is in line with the findings of Ainsworth and Fraser, 21 Conture and Fraser, 22 Costello 41 and Meyers and Freeman. 40All of these other studies hypothesized that alterations in pa-rental speaking rates influenced the speaking rates of stuttering children.Moreover, the present study was in line with Meyers and Freeman, 40 in concluding that the more the child stuttered, the slower he talked, and the slower the child talked, the faster the mother interacting with him talked.However, it is equally possible to interpret this analysis as demonstrating that the faster a mother spoke, the more the child stuttered,

REFERENCES
and the more he stuttered the slower he talked, and so forth.
There are several possible reasons why mothers might use a faster speaking rate when talking to a slow-talking or stuttering child.First, stuttering behavior may alter dialogue patterns.That is, a slow-speaking and/or stuttering child may disrupt the pace of the ongoing interaction, thus prompting the mother to speed her rate in the hope of increasing the child's rate.By talking faster, a mother may press the child to talk faster, and talking faster may lead to increased stuttering.Alternatively, a child's struggle for fluency, or his frequent dysfluency, may create internal discomfort, tension, anxiety or "nervousness" in his mother.Such internal reactions may alter a mother's speech motor behavior, thereby causing her to speak faster. 40

CONCLUSION
The findings from the present study suggest that the speech rates of mothers and their children who stutter are important indicators of fluency levels among stuttering children and should be incorporated in the assessment and treatment of stuttering.Mothers, as their children's main communication partners, have an important role in the therapy process and in setting clinical strategies.

Figure 1 .
Figure 1.Severity index and syllables per minute among mothers.

Figure 2 .
Figure 2. Severity index and syllables per minute among the children who stuttered.

Table 1 .
Comparison between mothers' speaking rates and children's stuttering severity *statistically significant; CI = confidence interval; SD = Standard Deviation.

Table 2 .
Comparison between speaking rates of mothers and children *statistically significant; SD = standard deviation.

Table 3 .
Comparison between children's speaking rates and their stuttering severity *statistically significant; CI = confidence interval; SD = standard deviation.