November 18, 2003 Feature

Cluttering Updated

Most speech-language pathologists are aware of the fluency disorder known as cluttering, and most seasoned clinicians have managed a few clients with the disorder. Many remember these clients not by how well they responded to treatment but by how puzzling it was to know what to do with them and how challenging they were to treat.

Those who have reviewed the literature on cluttering are often struck by the paucity of research and the lack of a widely accepted definition. The list of cluttering symptoms (see sidebar on p. 21) and the commentaries from those with the disorder (see sidebar at the top right of p. 5) explain, in part, why defining cluttering is so difficult: It is hard to know which symptoms are essential to the disorder and which are incidental.


Our research has advanced the following working definition: "Cluttering is a syndrome characterized by a speech delivery rate which is either abnormally fast, irregular, or both. In cluttered speech, the person’s speech is affected by one or more of the following: (1) failure to maintain normally expected sound, syllable, phrase, and pausing patterns; (2) evidence of greater than expected incidents of disfluency, the majority of which are unlike those typical of people who stutter." An example of cluttered speech can be seen in the sidebar at the center of p. 5.

This definition expands previous definitions that focused only on two components: an excessively rapid and/or irregular speaking rate, and disfluencies that are frequent but are not judged to be stuttering. Like all working definitions, this one must change as new data are gathered. Admittedly, the definition is not wholly satisfactory, partly because it is based on listener judgment. One especially frustrating problem is that people with the disorder frequently do not clutter, for example, when they speak in a short screening evaluation. In such cases, they either are not diagnosed or one must rely on subjective reports, by the client or others, that cluttering does indeed exist.

Another vexing issue is the extent to which language planning and pragmatic problems are implicated in the diagnosis of cluttering. We do not currently include language difficulties in the definition because there appear to be at least a few clutterers for whom language problems are not evident. A third confusing issue is that cluttering often—but not always—coexists with stuttering, although the two are now regarded as distinct fluency disorders by most authorities. Moreover, cluttering is often noticed before the stuttering takes over during development of the disorders and after stuttering is treated successfully, but not while a person manifests significant stuttering. Further adding to this confusion, even in relatively rare cases of "pure cluttering," is that most clutterers or their families refer to their problems as "stuttering."

Regardless, we are currently convinced that rate problems are somehow central to cluttering. There is the near universal impression that clutterers try to talk too fast, so fast that their speech intermittently breaks down. This explains the common clinical impression that most cluttering disfluencies result from placing excessive demands on the output capabilities of the speaker’s linguistic and other systems. Clutterers also tend to slur or omit syllables of longer words, which compromise intelligibility during spurts of rapid speech.

Many other symptoms have been reported in people who clutter. These optional symptoms include: lack of awareness of the problem; family history of fluency disorders; poor handwriting; confusing, disorganized language or conversational skills; temporary improvement when asked to "slow down" or "pay attention" to speech; misarticulations; poor intelligibility; social or vocational problems; distractibility; hyperactivity; auditory perceptual difficulties; learning disabilities; and apraxia.

There are very few solid research data on cluttering. Our own efforts have focused on acoustic and perceptual characteristics of cluttered speech, but we have also explored some experimental treatments. Our findings are preliminary and must be confirmed in larger studies. Assuming that the scientific and clinical communities will eventually agree on a definition of cluttering, we are hopeful that a great deal more research will be forthcoming.

Evaluating Cluttering

The decision regarding whether or not cluttering is present must consider whether a client manifests cluttering in a relatively pure form or in conjunction with stuttering. In the latter case, it is important to recognize that cluttering sometimes does not emerge as a salient condition until stuttering has remitted, either spontaneously or from treatment. Also, it is important to document the possible presence of other coexisting communication, learning, or attention deficit hyperactivity disorders.

In spite of the fact that we have tried to limit our definition to essential symptoms, a wide range of potential cluttering symptoms makes it important to search for many potential contributing problems in clinical management of specific clients. The evaluation is likely to require more than one session and may involve a diagnostic team, including an SLP, audiologist, classroom teacher, special educator, psychologist, and occasionally, neuropsychologist.

As in most speech-language evaluations, the case history should include information regarding the primary reason for seeking the evaluation, birth and developmental history, onset, course, past treatment, family history of speech or language disorders, and prior treatment. In addition, it should include questionnaire or interview data on learning and behavioral problems in school or work settings, given the likelihood of coexistence of cluttering with such disorders as attention deficit hyperactivity disorders, learning disabilities, and auditory processing disorders.

We recommend recording the clutterer in a variety of speaking tasks (for subsequent analyses of fluency, rate, articulation, language, and voice), including rote tasks (e.g., counting or reciting memorized material), singing, imitation, oral reading, and spontaneous speech. Older clutterers should read some words that are difficult to pronounce (e.g., "statistics," "chrysanthemum") and some with changing stress pattern sequences such as "apply, application, applicable" (a_ply’ / a_pli_ca’_tion / a_pli’_ca_ble). Also, it is important that the conversation allow assessment of pragmatic language abilities.

We are experimenting with a software program, developed by Bakker, which is designed to provide a measure of the percentage of total speaking time cluttered. This global measure has considerable potential for real-time judgments of a wide variety of cluttering symptoms.

To determine if cluttering coexists with stuttering, we suggest categorizing disfluencies using Campbell and Hill’s Systematic Disfluency Analysis. Typical non-stuttering categories include hesitations, interjections, revisions, unfinished words, and phrase repetitions. Typical stuttering categories are sound or syllable repetitions, prolongations, or blocks. Word repetitions can belong to either category. The clinician should determine the duration and severity of disfluencies and identify accessory or secondary behaviors.

Measuring speaking rate is especially important in cluttering. Unfortunately, there are no established norms for comparing speakers and speech across differences in age, task, familiarity with content, length of utterance, and effectiveness of monitoring. Currently, syllables per minute (SPM) is the most commonly used measure. Average conversational rates for normal preschoolers are reported to range from 110-180 SPM; for elementary aged children from 140-200 SPM; and for adults from 180-220 SPM.

Clinicians interested in fluent speech will find "articulatory rate" computed in syllables per second (SPS) to be more appropriate. SPS rates are usually reported for standard diadochokinetic tasks, that is, rapidly alternating productions of syllables such as "puh-tuh-kuh." Typical adult articulatory rates range from 6-7 SPS in conversation. Discounting pauses, SPS figures can be converted to SPM. The SPM of clutterers typically are higher than the norms for conversational speech reported above.

We suggest documenting rate differences between the clutterer’s slowest and most rapid speech and changes while speaking under conditions of delayed auditory feedback (DAF) or trying to talk as clearly as possible. A questionnaire regarding perceptions of speaking difficulty (see Daly’s adaptation of Woolf’s Perceptions of Stuttering Inventory) can estimate a client’s awareness of fluency or intelligibility problems. We also recommend adapting other measures of stuttering—for example, the St. Louis Inventory of Life Perspectives and Stuttering—to assess the degree of penalty or suffering that accrues from cluttering.

We suggest perceptual ratings, on 9-point scales, of short speech samples for such dimensions as: intelligibility, naturalness, overall speech rate, regularity of rate, disfluencies, overall articulation accuracy, and pragmatic language appropriateness. An oral examination that assesses oral-motor commands and diadochokinetic tests should be given, such as the Oral Speech Mechanism Screening Examination. Finally, the following measures should typically be added to the "standard" fluency evaluation: artic ulation testing, standardized and naturalistic language assessment, and central auditory processing testing. Also, if indicated, referrals for academic and/or cognitive testing should be made.

Using Daly and Burnett’s Checklist for Possible Cluttering can alert the clinician to a number of symptoms that are frequently observed in cluttering, although we agree with the authors that the instrument should not be used as the sole criterion for a diagnosis of cluttering.

Treating Cluttering

Therapy for cluttering should be tailored to the client’s unique difficulties since there are few data available suggesting standard procedures for treatment. Nevertheless, a number of therapeutic strategies have been recommended over the years, many of which we have found to be effective with specific clutterers. Importantly, these include speech, language, and other skills that may affect the clutterer’s ability to communicate effectively. We have selected common goals or principles for cluttering treatment and prioritized them as follows: slowing rate; heightening monitoring; using clear articulation; using acceptable, organized language; interacting with listeners; speaking naturally; and reducing excessive disfluencies. The following sections illustrate each principle.

  • Slowing Rate

    Slowing, more than any other goal, can be effective in ameliorating the entire range of cluttering symptoms. This may seem easy, but SLPs should remember that it is much more difficult for a clutterer to achieve and maintain a slow rate than for a normal speaker. Whatever the difficulty, we believe that clinicians should persevere until they find an effective strategy, remembering that simply nagging a client to "slow down" is not helpful and perhaps detrimental. Clinicians should also be aware that speech rate often increases as the degree of emotionality of the topic increases.

    Delayed auditory feedback is sometimes helpful in slowing rate and may be worth trying. Another strategy is to point out rapid spurts of speech as they occur, and to follow them with slower models for the client to imitate. Clinicians can give "speeding tickets" to help clients to remember to use a slower rate. Rapid, cluttered speech segments can be tape recorded and then transcribed in written form—with no spaces between the words—to highlight the need to pause between phrases and between some words.

    For a clutterer who is weary of being reminded by others to "slow down," slower speech may easily be achieved by matching the duration of his production of a sentence to a prerecorded sentence model on a device that can record and display electronically frequency and/or intensity tracings over several seconds. By superimposing his frequency or intensity tracing on that of the clinician, the client can approximate the clinician’s slow or normal rate.

  • Heightening Monitoring

    Clutterers must often learn to monitor their speech. Many are unable or reluctant to think about their speech, especially in the absence of cues that might increase their attention to it when they are speaking casually. Teaching a client to monitor effectively is not easy; imagination and careful observation are essential to create or select optimal strategies. All the rate reduction strategies (above) require heightened monitoring. Analysis of videotaped or audiotaped conversations can be used to identify places where monitoring seemingly broke down. Adult clutterers can be asked to imagine themselves speaking clearly prior to communication and use self-talk and affirmation to strengthen those images. Clinicians can prepare an audiotape for clients with samples of their worst, questionable, and best examples of speech and then help them adopt a discipline of listening to that tape several times a day to enhance monitoring.

  • Using Clear Articulation

    Slowing the rate or learning to monitor more effectively often results in clearer speech. If not, additional treatment is needed. Systematic misarticulations should be targeted by conventional articulation treatment strategies. Commonly, such errors have been the focus of considerable (and often unsuccessful) prior treatment. If so, cluttering treatment should aim to integrate learned changes into the speech pattern. Sometimes, it is necessary to practice short sentences to elicit the best compromise between unclear, cluttered speech versus correct—but "over-articulated" and unnatural—speech. When multisyllabic words are "telescoped" by cluster reductions or deletions of weak syllables, reading multisyllabic words can help the clutterer learn to include "all the sounds."

  • Using Acceptable, Organized Language

    Language treatment is recommended if the strategies described above have not been fully effective. More syntactically acceptable sentences and coherent narratives may be elicited by beginning with simple, short sentences, and progressing to longer, more complex ones. The clinician can transcribe some of the cluttered utterances, show clients the "mazes" (i.e., run-on, rambling verbiage that adds no useful information) within them, and ask them to repeat their message including only the essential information (see the "maze" example on p. 5). Similarly, clients may be taught to outline the content (the "what") of the description or story, and then the form (the "how") of the same message with all and only the necessary words and explanations to make it clear. Some clutterers will need considerable assistance and practice to learn to tell a story logically and sequentially.

  • Interacting with Listeners

    Clutterers often need training in anticipating, perceiving, and responding to standard cues provided by listeners during conversations. Training may need to start with rules for turn-taking such as, "Talk while your partner listens; then listen while he talks," and progress to learning to respond to such subtle signals of confusion as the wrinkling of a listener’s brow. Finally, the clutterer can benefit from "checking in" periodically with the listener by asking, "Did you get that?" or "Should I repeat that?”

  • Speaking Naturally

    Rapid, irregular rates as well as slow, robotic rates are perceived as unnatural. When indicated, we recommend teaching cluttering clients to vary both syllable durations (especially stressed syllables) and intonation contours. We provide immediate feedback for speech that sounds artificial or strange. Imitating clinician models of both intensity and frequency tracings on the Visi-Pitch®, in addition to helping slow the rate, can be effective in teaching a speaker how to vary pitch and loudness in order to sound more natural.

  • Reducing Excessive Disfluencies

    Recalling that many clutterers also stutter, we assume that stuttering, if present, will have been treated through conventional therapies. Yet, paradoxically, we recommend that excessive disfluencies should be the last aspect of speech to be targeted, especially in clutterers with very little or no stuttering. After targeting rate, monitoring, articulation, and language, if cluttering disfluencies persist, they should also be targeted in treatment. In these cases, we recommend fluency shaping strategies to reduce the occurrence of disfluencies to an acceptable level.

These are therapeutic goals of the SLP. Clutterers may well present with other problems. Who deals with them is as much a matter of tradition as expertise. In school children, SLPs will ordinarily invoke the expertise of the learning disabilities specialist, the behavior disorders specialist, or the school psychologist. Options are fewer for adults who clutter. In such cases, SLPs will often do these things themselves or refer clients to literacy tutors and other specialists.

As cluttering becomes more widely recognized, we can expect to see more clutterers populating caseloads of SLPs. If so, clinicians will face continuing challenges to identify symptoms and apply effective treatments for this disorder. Our long-term goal has been to "put cluttering on the map" such that, first and foremost, a consensus on a standard definition of cluttering will emerge. After that occurs, we believe that improved understanding of the incidence, cause, diagnosis, and treatment of cluttering will no doubt follow.

Kenneth O. St. Louis, professor at West Virginia University, is a Board Recognized Specialist in Fluency Disorders and an associate editor of the Journal of Fluency Disorders. He has focused on research, clinical management, and teaching in fluency disorders for more than 30 years and has carried out research on cluttering for nearly 20 years. Contact him by e-mail at

Lawrence J. Raphael, teaches in the Department of Communication Sciences and Disorders at Adelphi University. He has published research on the acoustics, physiology, and perception of speech and is a co-author of Speech Science Primer (4th ed.) and co-editor of Language and Cognition and Producing Speech. Contact him by e-mail at

Florence L. Myers, professor at Adelphi University, has presented numerous papers on cluttering and childhood stuttering. She has co-authored books, book chapters and journal articles on fluency and its disorders. She is a former associate editor of the  Journal of Fluency Disorders. Contact her by e-mail at

Klaas Bakker, of Southwest Missouri State University has specialized in fluency disorders (stuttering and cluttering) since the early 1980s. His research has emphasized assessment and measurement of aspects of speech fluency and rate. He is an associate editor of the Journal of Fluency Disorders and a Board Recognized Specialist in Fluency Disorders. Contact him by e-mail at

cite as: St. Louis, K. O. , Raphael, L. J. , Myers, F. L.  & Bakker, K. (2003, November 18). Cluttering Updated. The ASHA Leader.

More on Cluttering

Verbatim Descriptions of Cluttering

"Oh, I think I my speech is garbled. I speak too fast…Other people always say 'What did you say to me? Speak slower please'….I hear I hear myself. Uh my my words get garbled to myself I garble my words…"

(illustrating difficulties in articulation, speech intelligibility, and rate)

"It's mostly like explanation of something. Like I want to say something is I I mean to say 'it's extemporaneous,' but I can't think of the word 'extemporaneous' - I think of uh - it's something you say as it comes out of the - you can't remember - that sort of thing, y'know?"

(illustrating difficulties in language)

Example of a Cluttering "Maze"

(rambling, run-on verbalizations that add nothing to the content of the message)

"I know myself I speak and I and I know if I slow down and speak properly people will understand me… People know me used to me. They used to hear - understand it… I think since uh um since um after college it started getting worse and - worse and worse. After uh in school I went I had speech classes and so forth and I know I had uh - I used to - you used to have to record your speech and uh listen to yourself…"

Authors' Research Results

Cluttered speech

  • Most common disfluency categories: unfinished words, interjections, and revisions
  • Unfinished words, interjections, and revisions occur in clusters of disfluencies
  • Least acceptable to listeners for speech rate and naturalness; somewhat more acceptable for articulation; most acceptable for fluency and language
  • Reduced voice onset times; irregular syllable durations; severely shortened vowels; compressed consonant clusters
  • Consistently more "intended" syllables (based on listener's judgments of what is being said) than "actual" syllables (based on acoustic characteristics of spectrograms). Compared to cluttered speech samples, rehearsed samples actually faster (measured acoustically).


  • Slower than controls with diadochokinetic syllables at comfortable and fast rates; less successful at increasing speech rate after instruction to talk "even faster"
  • Often aware of cluttering but unable to change it
  • Faster speech rates and more cluttering symptoms in severe clutterer versus mild-moderate clutterer
  • Positive response to delayed auditory feedback (DAF) therapy (severe clutterer); negative response to DAF (mild-moderate clutterer)
  • Positive response to awareness, modeling, and contingent management therapy (mild-moderate clutterer)

Cluttering References

American Speech-Language-Hearing Association.(1999, March). Terminology pertaining to fluency and fluency disorders: Guidelines. Asha.41 (Supplement 19), 29–36.

Bakker, K., Bos, C., St. Louis, K. O., Myers, F. L., & Raphael, L. J.(1999).Articulation rates and spectrographic characteristics of cluttered speech. Paper presented at the Annual Convention of the American Speech-Language-Hearing Association, San Francisco, CA.

Bakker, K., Bos, C., & Finn, P.(1999).Counting syllables or words: Implications for speech rate determination. Paper presented at the Annual Convention of the American Speech-Language-Hearing Association, San Francisco, CA.

Bakker, K., Raphael, L. J., Myers, F. L., & St. Louis, K. O.(2000).Acoustic and perceptual-phonetic analyses of cluttered and noncluttered speech. Paper presented at the Annual Convention of the American Speech-Language-Hearing Association, Washington, DC.

Campbell, J. G., & Hill, D. G.(1994).Systematic disfluency analysis. Evanston, IL: Northwestern University.

Daly, D. A.(1986).The clutterer.In K. O. St. Louis (Ed.).The atypical stutterer (pp. 155–192). New York: Academic Press.

Daly, D. A.(1988).The freedom of fluency. East Moline, IL: LinguiSystems.

Daly, D. A. (1992).Helping the cluttering: Therapy considerations.In F. L. Myers & K. O. St Louis (Eds.).Cluttering: A clinical perspective (pp. 107–124).Kibworth, Great Britain: Far Communications. (Reissued in 1996 by Singular, San Diego, CA.)

Daly, D. A.(1996).The source for stuttering and cluttering. East Moline, IL: LinguiSystems.

Daly, D. A., & Burnett, M.(1999).Cluttering: Traditional views and new perspectives.In R. F. Curlee (Ed.).Stuttering and related disorders of fluency, 2nded. (pp. 222–254). New York: Thieme Medical Publishers.

Guitar, B. (1998).Stuttering: An integrated approach to its nature and treatment, 2nd ed. Baltimore: Wlliams & Wilkins.

Helm, K.(1997).A perceptual, acoustic-phonetic, and linguistic analysis of cluttering.Unpublished master’s thesis.Southwest Missouri State University, Springfield, MO.

Ingham, R. J.(1984). Stuttering and behavior therapy: Current status and experimental foundations. San Diego, CA: College-Hill.

Kent, R. D.(1997). The speech sciences. San Diego, CA: Singular.

Myers, F. L., & Bradley, C. L.(1992).Clinical management of cluttering from a synergistic framework.In F. L. Myers & K. O. St. Louis (Eds.).Cluttering: A clinical perspective (pp. 85–105).Kibworth, Great Britain: Far Communications. (Reissued in 1996 by Singular, San Diego, CA.)

Myers, F. L., & St. Louis, K. O.(1996).Two youths who clutter, but is that the only similarity? Journal of Fluency Disorders, 21, 297–304.

Myers, F. L.,  & St. Louis, K. O.(Eds.). Cluttering: A clinical perspective (pp. 85–105).Kibworth, Great Britain: Far Communications. (Reissued in 1996 by Singular, San Diego, CA).

Myers, F. L., St. Louis, K. O., Bakker, K., Raphael, L. J., Wiig, E. K., Katz, J., Daly, D. A., & Kent, R. D.(2002a). Putting cluttering on the map: Looking ahead. Seminar presented at the Annual Convention of the American Speech-Language-Hearing Association, Atlanta, GA.

Myers, F. L., St. Louis, K. O., Bakker, K., Raphael, L. J., Wiig, E. K., Katz, J., Daly, D. A., & Kent, R. D.(2002b). Putting cluttering on the map: Looking back. Seminar presented at the Annual Convention of the American Speech-Language-Hearing Association, Atlanta, GA.

Myers, F. L., Stueber, K. A., & St. Louis, K. O.(1997).Clustering of disfluencies in cluttering. Poster presented at the Annual Convention of the American Speech-Language-Hearing Association, Boston, MA.

Pindzola, R., Jenkins, M., & Lokken, M.(1989).Speaking rates of young children.Language, Speech, and Hearing Services in Schools, 20, 133–138.

Raphael, L. J., Bakker, K., Myers, F. L., St. Louis, K. O., & Mac Roy, M. (2001).Articulatory/acoustic features of DDKs in cluttered, tachylalic, and normal speech. Paper presented at the Annual Convention of the American Speech-Language-Hearing Association, New Orleans, LA.

St. Louis, K. O.(1992). On defining cluttering.In F. L. Myers & K. O. St Louis (Eds.).Cluttering: A clinical perspective (pp. 37–53).Kibworth, Great Britain: Far Communications. (Reissued in 1996 by Singular, San Diego, CA.)

St. Louis, K. O.(Guest Ed.). (1996). Research and opinion on cluttering: State of the art and science (special edition). Journal of Fluency Disorders, 21.

St. Louis, K. O.(2001). Living with stuttering: Stories, basics, resources, and hope. Morgantown, WV: Populore.

St. Louis, K. O., & Myers, F. L.(1995).Clinical management of cluttering.Language, Speech, and Hearing Services in Schools, 26, 187–195.

St. Louis, K. O., & Myers, F. L.(1997).Management of cluttering and related fluency disorders. In R. F. Curlee & G. M. Siegel (Eds.), Nature and treatment of stuttering: New directions, 2nd ed. (pp. 313–332). New York: Allyn & Bacon.

St. Louis, K. O., Myers, F. L., Cassidy, L. J., Michael, A. J., Penrod, S. M., Litton, B. A., Olivera, J. L. R., & Brodsky, E.(1996). Efficacy of delayed auditory feedback for treating cluttering: Two case studies. Journal of Fluency Disorders, 21, 305–314.

St. Louis, K. O., & Ruscello, D. M.(2000).Oral speech mechanism screening examination, 3rd ed. Austin, TX: Pro-Ed.

Woolf, B.(1967). The assessment of stuttering as struggle, avoidance, and expectancy.British Journal of Disorders of Communication, 2, 158–171.


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