Signs and symptoms of stuttering include primary behaviors, such as
- monosyllabic whole-word repetitions (e.g., "Why-why-why did he go there?"),
- part-word or sound/syllable repetitions,
- prolongations of sounds,
- audible or silent blocking (filled or unfilled pauses in speech),
- words produced with an excess of physical tension or struggle.
These signs and symptoms are consistent with the diagnostic criteria for childhood-onset fluency disorder (stuttering) listed in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5; American Psychiatric Association, 2013).
Frequency and severity of stuttering may fluctuate from day to day and in relation to the speaking situation. Stuttering is often more severe when there is increased pressure to communicate (e.g., competing for talk time, giving a report at school, interviewing for a job).
Secondary, avoidance, or accessory behaviors that may impact overall communication include
- distracting sounds (e.g., throat clearing, insertion of unintended sound);
- facial grimaces (e.g., eye blinking, jaw tightening);
- head movements (e.g., head nodding);
- movements of the extremities (e.g., leg tapping, fist clenching);
- sound or word avoidances (e.g., word substitution, insertion of unnecessary words, circumlocution);
- reduced verbal output due to speaking avoidance;
- avoidance of social situations;
- fillers to mask moments of stuttering.
Concomitant speech and language behaviors may include
- articulation or phonological disorder (St. Louis & Hinzman, 1988; Wolk et al., 1993);
- language differences. Children who stutter
- score within or above the average range on tests of language ability (Watkins, Yairi, & Ambrose, 1999). However, children who stutter tend to show lower performance (although still within the average range) on standardized tests of receptive and expressive language and other language measures when compared with children who do not stutter (Anderson, Pellowski, & Conture, 2005; Ntourou et al., 2011);
- use significantly fewer verbs overall and fewer different verbs than those used by children who do not stutter (Wagovich & Bernstein Ratner, 2007);
- have more frequent use of irregular past-tense forms and a tendency to double-mark (e.g., "ranned") these forms when compared with verb use of children who do not stutter (Bauman, Hall, Wagovich, Weber-Fox, & Ratner, 2012);
- produce significantly more stutter-like disfluencies in narrative contexts than in conversational contexts (Byrd, Logan, & Gillam, 2012).
Children who stutter may show expressive language problems because of a tendency to avoid speaking. Avoidance can lead to less talking and reduced linguistic complexity (Silverman & Bernstein Ratner, 2002).
Signs and symptoms of cluttering include
- rapid and/or irregular speech rate;
- excessive coarticulation resulting in the collapsing and/or deletion of syllables and/or word endings;
- excessive disfluencies, which are usually of the more nonstuttering type (e.g., excessive revisions and/or use of filler words, such as "um");
- pauses in places typically not expected syntactically;
- unusual prosody (often due to the atypical placement of pauses rather than a "pedantic" speaking style, as observed in many with ASD).
The speaker's rate of speech is not always measured to be greater than average, but is perceived by the listener as rapid. This is thought to be because speakers with cluttering speak at a rate that is too fast for their systems to handle, resulting in breakdown of clarity of speech (Myers, 1992; St. Louis, Myers, Bakker, & Raphael, 2007; Ward, 2006). Although some with cluttering lack awareness of their difficulties with communication, many are aware that others have difficulty understanding them. People with cluttering can experience the same affective and cognitive components as those with stuttering, including communication avoidance, anxiety, and/or negative attitudes toward communication (Scaler Scott & St. Louis, 2011).