The duration component of the stress effect in stuttering

The purpose of the present study was to investigate whether there is a relationship between stuttering on stressed syllables and the duration of these syllables. Sixteen adults who stutter read a text consisting of 226 syllables. The relative stress of each syllable was rated, and syllables were categorized into long- and short-stressed syllables, unstressed syllables and intermediate syllables lying in-between. In order to isolate effects caused by within-word position from those caused by linguistic stress, syllables in initial and in subsequent positions were analyzed separately. In both word position categories stressed syllables were stuttered more often than unstressed syllables. Stuttering frequency of intermediate syllables seems to be in-between stressed and unstressed syllables, just as their stress level is rated in-between. Results regarding the duration of stressed syllables do not allow final conclusions.

Educational objectives: The reader will learn about and be able to describe (1) language factors related with stuttering events, (2) the stress effect in adults who stutter, and (3) methods to control for its confounding variables.     

Stuttering and syllable stress

Eighteen adult stutterers read two lists each of 16 bisyllabic words. In one list, stress appeared on the first syllable; in the second, the “same” words carried second syllable stress. There proved to be no significant difference in proportion between stressed and unstressed syllables associated with stuttering. This investigation appears to dispute the proposition that stressed syllables provide the focal points of stuttering (Wingate, 1976).     

Predicting stuttering from linguistic factors for German speakers in two age groups

Brown's factors [J. Speech Disorders 10 (1945) 181] predict the likely loci of disfluency in English-speaking adults who stutter. A word is more likely to be stuttered for these speakers if it is a content word, starts with a consonant, is positioned at the beginning of a sentence, and if it is a long word. These same factors were examined in native German-speaking children and adults who stutter. Speech data of 15 German adults and 17 children were coded according to Brown's factors. For the adult group, it was predicted that words starting with consonants would not lead to as much of an increase in disfluencies compared with English samples, because of cross-linguistic differences in syllable onset properties. It was predicted that stuttering would be more likely in later sentence positions in German because in German the verb is usually near the end of a sentence. There were no obvious reasons to expect differences on the two remaining factors, content words and word length. With children, it was hypothesised that Brown's factors that specify level of linguistic difficulty would not be such a good predictor of stuttering rate. Specifically, it was predicted that the difference in stuttering rate between function and content words would be lower in children. For the adults both word type (content/function) and word length increased stuttering rate significantly, whereas changes in stuttering rate for the other two factors were non-significant. It was also found that when word difficulty (based on a combined measure of all factors) increased, stuttering rate rose. With children, only the word-length factor was significant, and stuttering rate was not governed to the same extent by overall word difficulty. Conclusions are drawn as to the effect of linguistic and motor influences on stuttering. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to describe: (1) how linguistic factors affect stuttering rates in German; (2) the different patterns of adults and children who stutter and how language might influence this pattern; and (3) how to interpret these findings in light of a current theory of fluency failure.     

Disfluency data of German preschool children who stutter and comparison children

This study compared the disfluencies of German-speaking preschool children who stutter (CWS, N = 24) with those produced by age- and sex-matched comparison children who do not stutter (CWNS, N = 24). In accordance with Yairi and Ambrose's [Yairi, E., & Ambrose, N. (1992). A longitudinal study of stuttering in children: A preliminary report. Journal of Speech and Hearing Research, 35, 755-760] guidelines the CWS group had a narrow age range (2-5 years) and were seen close to the reported time of their stuttering onset (average of 8 months). Furthermore, over 95% of the CWS group had not received any type of speech therapy intervention. Consistent with previous findings for English-speaking preschool children, 'stuttering-like' disfluencies (prolongations, blocks, part- and one-syllable word repetitions) were significantly more frequent in CWS (mean = 9.2%) than in CWNS (mean = 1.2%), whereas no significant group differences occurred with respect to 'normal' disfluencies. The number of iterations in stuttering-like disfluencies was also significantly higher in CWS (mean = 1.28 iterations) than in CWNS (mean = 1.09 iterations). In contrast to previous findings, a sub-group of children who have been stuttering for a shorter time (1-5 months) did not differ from a sub-group who had stuttered for a longer period (8-22 months). EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe how German-speaking preschool children who stutter and who do not stutter display stuttering-like and normal disfluencies including number of iterations; (2) explain how powerful classification measures for the diagnosis of stuttering are for German-speaking preschool children; (3) discuss how disfluency patterns of native English- and German-speaking children close to onset of stuttering differ.     

Specific subtype of fluency disorder affecting French speaking children: A phonological analysis

PurposeClinicians working with fluency disorders sometimes see children whose word repetitions are mostly located at the end of words and do not induce physical tension. Prior studies on the topic have proposed several names for these disfluencies including “end word repetitions”, “final sound repetitions” and “atypical disfluency”. The purpose of this study was to use phonological analysis to explore the patterns of this poorly recognized fluency disorder in order to better understand its specific speech characteristics.MethodsWe analyzed a spontaneous language sample of 8 French speaking children. Audio and video recordings allowed us to study general communication issues as well as linguistic and acoustical data.ResultsWe did not detect speech rupture or coarticulation failures between the syllable onset and rhyme. The problem resides primarily on the rhyme production with a voicing interruption in the middle of the syllable nucleus or a repetition of the rhyme (nucleus alone or nucleus and coda), regardless of the position in the word or phrase.ConclusionThe present study provides data suggesting that there exist major differences in syllable production between the disfluencies produced by our 8 children and stuttered disfluencies. Consequently, we believe that this fluency disorder should be recognized as distinct from stuttering.     

汉语语句重音的分类和分布

通过两个独立进行的重音标注实验对汉语语句重音的分类和分布进行了初步探讨。实验l是由60位普通被试参加的音节重音突显度的知觉实验。实验2是由本文三位作者参加的重音类别标注实验,在此实验中语句重音被划分为节奏重音和语义重音。实验2中对于语句重音的分类性标注结果得到了实验l中普通被试对音节重音突显度知觉结果的支持,这说明人们确实能够感知到两种不同类型的重音。实验结果还表明,节奏重音倾向于出现在较大韵律单元内的最末韵律词的末音节上,并且与适当的停延相伴生,语义重音的分布则与语句的韵律结构的关系不大。     

Childhood stuttering and speech disfluencies in relation to children's mean length of utterance: a preliminary study

The purpose of this study was to examine the influence of utterance length and complexity relative to the children's mean length of utterance (MLU) on stuttering-like disfluencies (SLDs) for children who stutter (CWS) and nonstuttering-like disfluencies (nonSLDs) for children who do not stutter (CWNS). Participants were 12 (3;1-5;11, years;months) children: 6 CWS and 6 age-matched (+/-5 months) CWNS, with equal numbers in each talker group (CWS and CWNS) exhibiting MLU from the lower to the upper end of normal limits. Data were based on audio-video recordings of each child in two separate settings (i.e., home and laboratory) during loosely structured, 30-min parent-child conversational interactions and analyzed in terms of each participant's utterance length, MLU, frequency and type of speech disfluency. Results indicate that utterances above children's MLU are more apt to be stuttered or disfluent and that both stuttering-like as well as nonstuttering-like disfluencies are most apt to occur on utterances that are both long and complex. Findings were taken to support the hypothesis that the relative "match" or "mismatch" between linguistic components of an utterance (i.e., utterance length and complexity) and a child's language proficiency (i.e., MLU) influences the frequency of the child's stuttering/speech disfluency. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to: (1) compare different procedures for assessing the relationship among stuttering, length and complexity of utterance, (2) describe the difference between relative and absolute measures of utterance length, (3) discuss the measurement and value of mean length of utterance and its possible contributions to childhood stuttering, and (4) describe how length and complexity influence nonstuttering-like disfluencies of children who stutter as well as the stuttering-like disfluencies of children who do not stutter.     

Converting between word and syllable counts in children's conversational speech samples

Several authors have suggested that it is possible to convert between word and syllable counts for basic clinical measurements such as the frequency of speech disfluencies or speaking rate in conversational speech samples. Based primarily on results from adults' speech samples, proposed conversion factors have averaged approximately 1.5 syllables per word. Because children produce fewer multisyllabic words than adults, this conversion factor is probably not appropriate for children's speech samples. This study sought to develop a more accurate conversion factor for children's speech by comparing syllable and word counts in spontaneous speech samples produced by 50 children, age 3 to 5. Analyses revealed an average ratio of 1.15 syllables per word, which was consistent across different subjects, across subject groups (children who stutter and children who do not stutter) and also, somewhat surprisingly, across age groups (3-year olds, 4-year olds, and 5-year olds). Results suggest that this constant conversion factor of 1.15 can be used to convert between word and syllable with sufficient precision to allow clinicians to compare their data to published guidelines and benchmarks about childhood stuttering.     

A randomized control trial to investigate the impact of the Lidcombe Program on early stuttering in German-speaking preschoolers

In order to investigate whether the Lidcombe Program effects a short-term reduction of stuttered speech beyond natural recovery, 46 German preschool children were randomly assigned to a wait-contrast group or to an experimental group which received the Lidcombe Program for 16 weeks. The children were between 3;0 and 5;11 years old, their and both of their parents’ native language was German, stuttering onset had been at least 6 months before, and their stuttering frequency was higher than 3% stuttered syllables. Spontaneous speech samples were recorded at home and in the clinic prior to treatment and after 4 months. Compared to the wait-contrast group, the treatment group showed a significantly higher decrease in stuttered syllables in home-measurements (6.9%SS vs. 1.6%SS) and clinic-measurements (6.8%SS vs. 3.6%SS), and the same increase in articulation rate. The program is considered an enrichment of currently applied early stuttering interventions in Germany.

Educational objectives: Readers will discuss and evaluate: (1) the short-term effects of the Lidcombe Program in comparison to natural recovery on stuttering; (2) the impact of the Lidcombe Program on early stuttering in German-speaking preschool children.     

Influences of rate, length, and complexity on speech disfluency in a single-speech sample in preschool children who stutter

The purpose of the present study was (1) to determine whether speech rate, utterance length, and grammatical complexity (number of clauses and clausal constituents per utterance) influenced stuttering-like disfluencies as children became more disfluent at the end of a 1200-syllable speech sample [Sawyer, J., & Yairi, E. (2006). The effect of sample size on the assessment of stuttering severity. American Journal of Speech-Language Pathology, 15, 36-44] and (2) to explore the interaction of speech rate, length, and grammatical complexity at the beginning (syllables 1-300, Section A) and the end (syllables 901-1200, Section B) of the speech sample. Participants were eight boys and six girls (M=40.9 months) who were selected from the Sawyer and Yairi [Sawyer, J., & Yairi, E. (2006). The effect of sample size on the assessment of stuttering severity. American Journal of Speech-Language Pathology, 15, 36-44] study. Mean length of utterance (MLU) in morphemes, the number of clauses, clausal constituents, and articulation rate, measured in syllables per second were analyzed from the children's conversational speech. The median split procedure [Logan, K., & Conture, E. (1995). Length, grammatical complexity, and rate differences in stuttered and fluent conversational utterances of children who stutter. Journal of Fluency Disorders, 20, 35-61; Yaruss, J. S. (1997). Utterance timing and childhood stuttering. Journal of Fluency Disorders, 22, 263-286] was used to study interactions between articulation rate, utterance length, and grammatical complexity across the two sections. The mean number of clauses per utterance, clausal constituents per utterance, and articulation rate revealed no significant differences between Section A and Section B, whereas MLU significantly increased in Section B (p=.013). Clausal constituents and MLU were significantly correlated both in Sections A and B. The median split procedure revealed trends for utterances characterized as high length and low-speech rate to be greater in number in Section B than A, but the differences were not significant. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to: (a) describe the influence of grammatical complexity and mean length of utterance on disfluent speech; (b) compare different procedures for assessing speech rate and determine why the effects of articulation rate have been inconclusive; (c) discuss procedures for comparing length, rate, and complexity across a single-speech sample; and (d) explain why therapeutic methods that emphasize shorter utterance lengths, rather than only slower speech rates, are advisable in establishing fluency in preschool children who stutter.     

Phonetic factors in letter detection: A reevaluation

Three experiments in which subjects searched for the letter e in printed text were conducted to examine the effects of phonetic factors in silent reading. In Experiment 1, subjects made more errors on silent es than on pronounced es, but silent es always occurred at the ends of words, whereas pronounced es occurred in the middle of words. In Experiment 2, all instances of the letter e occurred in the penultimate location in the words, and no effects of letter voicing were obtained. In Experiment 3, subjects made more errors on es in unstressed syllables than on es in stressed syllables in three-syllable words. However, this effect occurred only for es in the second and third syllables and only for the more common words. All three experiments yielded large effects of word frequency, which were reduced in passages printed in alternating typecase. It was concluded that letter detection is affected by syllable stress but not by letter voicing and that the stress effect depends on whether the subject is able to form reading units at the syllable level.     

Listeners’ perception of compensatory shortening

English exhibits compensatory shortening, whereby a stressed syllable followed by an unstressed syllable is measured to be shorter than the same stressed syllable alone. This anticipatory shortening is much greater than backward shortening, whereby an unstressed syllable is measured to shorten a following stressed syllable. We speculated that measured shortening reflects not true shortening, but coarticulatory hiding. Hence, we asked whether listeners are sensitive to parts of stressed syllables hidden by following or preceding unstressed syllables. In two experiments (Experiments 1A and 1B), we found the point of subjective equality—that is, the durational difference between a stressed syllable in isolation and one followed by an unstressed syllable—at which listeners cannot tell which is longer. In a third experiment (Experiment 2), we found the point of subjective equality for stressed monosyllables and disyllables with a weak-strong stress pattern. In all of the experiments, the points of subjective equality occurred when stressed syllables in disyllables were measured to be shorter than those in monosyllables, as if the listeners heard the coarticulatory onset or the continuation of a stressed syllable within unstressed syllables.     

Stottern

Stuttering is a fluency disorder with a point prevalence of approximately 1%. Stuttering begins in childhood and is characterized by frequently occurring breaks in the flow of speaking. These fluency breaks are repetitions of words and syllables, prolongations of sounds and pauses. Many people who stutter show avoidance behaviors, social anxiety, shame and social withdrawal. Empirical studies point to genetic origins of the disorder; however, distinct physical deficits causing stuttering are not yet known. While most children outgrow stuttering before adolescence those who do not typically continue to stutter throughout their life. The severity of stuttering as well as its impact on the quality of life can be reduced by a combination of cognitive-behavioral therapy and speech-language therapy.     

Loci of stuttering of English- and Korean-speaking children who stutter: Preliminary findings

PurposeThe purpose of the study was to determine whether differences exist between young English- and Korean-speaking children who stutter (CWS) in the loci of stuttering.MethodParticipants were 10 Korean-speaking and 11 English-speaking CWS between the ages of 3 and 7 years. Participants produced narratives while viewing various picture scenes and a wordless picture book.ResultsFindings indicated that Korean-speaking CWS stuttered more on content than function words whereas English-speaking CWS stuttered more on function than content words. Furthermore, both Korean- and English-speaking CWS tended to stutter more on utterance-initial words. These findings appear to be related to the differences in linguistic/syntactic structures between Korean and English. Specifically, in the Korean-speaking CWS’s narratives, most utterance-initial words (73.60 %) were content words whereas in the English-speaking CWS’s narratives, most utterance-initial words (83.57 %) were function words.ConclusionThese preliminary findings, although in need of replication with a larger sample size, seem to suggest that the word class (i.e., content/function words) contributions to stuttering loci are more language-specific whereas the word position (i.e., utterance-initial position) contributions to stuttering loci are more language-nonspecific. Given that the true characteristics of stuttering may be rather language-nonspecific than language-specific, further research may need to focus more on stuttering loci related to word position than word class.     

Language skills of children during the first 12 months after stuttering onset

PurposeTo describe the language development in a sample of young children who stutter during the first 12 months after stuttering onset was reported.MethodsLanguage production was analysed in a sample of 66 children who stuttered (aged 2–4 years). The sample were identified from a pre-existing prospective, community based longitudinal cohort. Data were collected at three time points within the first year after stuttering onset. Stuttering severity was measured, and global indicators of expressive language proficiency (length of utterances and grammatical complexity) were derived from the samples and summarised. Language production abilities of the children who stutter were contrasted with normative data.ResultsThe majority of children’s stuttering was rated as mild in severity, with more than 83% of participants demonstrating very mild or mild stuttering at each of the time points studied. The participants demonstrated developmentally appropriate spoken language skills comparable with available normative data.ConclusionIn the first year following the report of stuttering onset, the language skills of the children who were stuttering progressed in a manner that is consistent with developmental expectations.     

An experimental treatment using verbal punishment with two preschool stutterers

A multiple base-line experimental treatment was conducted with two preschool stuttering children. Each child conversed 20 min with the experimenter for 20 sessions. Treatment consisted of the presentation of the verbal stimulus “slow down” contingent upon a stuttering response. The percentage of words stuttered by both children decreased during the treatment sessions. Probe tape recordings conducted in each child's home revealed a decrease in stuttering frequency.     

Critical words and the locus of stuttering in speech

The locus of stuttering in the communicative speech of 26 stutterers was studied in situations where subjects received and conveyed specific information. It was hypothesized that a larger proportion of critical rather than noncritical words would be stuttered. Critical words were those which necessarily had to be pronounced if a listener should be able to understand and act according to the messages given. The critical words were selected by the experimenter before the experiment started. The results showed that 35.8% of the critical and 8.4% of the noncritical words were stuttered. There was also significantly more stuttering on critical words than on long noncritical words. The largest proportion of critical words appeared in the final position of sentences, which was also where most stuttering was located. Whole-word repetitions, an instance of normal nonfluency, were associated with noncritical words. No correlation between frequency of stuttering and whole-word repetitions was found.     

Communicative stress and stuttering frequency during normal,whispered, and articulation-without-phonation speech modes

The effect of communicative stress on the frequency of stuttered syllables in 12 adult stutterers reading six different but equivalent passages using normal voicing, whispering, and articulation-without-phonation speech under a stress and a non-stress condition was studied. Although the frequency of stuttering was significantly greater in the normal voicing mode than in the whispering mode and greater in the whispering mode than in the articulation-without-phonation mode, no differences were found between the stress and the nonstress conditions with respect to stuttering.     

The relationship between age and frequency of disfluency in preschool children

The frequencies of nine types of disfluency, including silent pauses, were studied in 60 nonstuttering males, 3.5 and 5 yr-of-age. The younger children evidenced significantly higher rates of part word, word, and phrase repetitions, incomplete phrases, and disrhythmic phonations. The older children demonstrated significantly more grammatical pauses. The two groups did not differ in the frequency of interjections, ungrammatical pauses, and revisions. The most powerful discriminating category between the two age groups was phrase repetition. The results are compared with findings from other recent investigations of disfluency in nonstuttering preschool males. Possible explanations for the discrepancies among the various investigations and for the high degree of variability in disfluency reported in the literature are proposed. The results of this investigation suggest that nonstuttering children begin to show more adult-like disfluency patterns toward the later preschool years.     

The use of rhythm in attending to speech

Three experiments examined attentional allocation during speech processing to determine whether listeners capitalize on the rhythmic nature of speech and attend more closely to stressed than to unstressed syllables. Ss performed a phoneme monitoring task in which the target phoneme occurred on a syllable that was either predicted to be stressed or unstressed by the context preceding the target word. Stimuli were digitally edited to eliminate the local acoustic correlates of stress. A sentential context and a context composed of word lists, in which all the words had the same stress pattern, were used. In both cases, the results suggest that attention may be preferentially allocated to stressed syllables during speech processing. However, a normal sentence context may not provide strong predictive cues to lexical stress, limiting the use of the attentional focus.