About the presenter: Yvonne van Zaalen-op 't Hof, PhD is director of the Communicative Assessment and Technology centre at Fontys University Eindhoven, the Netherlands. Dr. van Zaalen is an internationally respected researcher, lecturer and fluency specialist specialized in differential diagnostics in speech and language disorders. As head of the clinical committee of the International Cluttering Association Yvonne is responsible for the development of diagnostic and assessment protocols that speech language pathologists around the world can use to treat the intriguing disorder of cluttering.
About the presenter: Florence Myers, Ph.D., CCC/SLP is a Professor at Adelphi University, Garden City, New York. She has published widely in the areas of cluttering and stuttering. Her current interests include the nature of cluttering and how it relates to stuttering, as well as treatment approaches to cluttering. She was co-chair of the executive committee to organize the First International Conference on Cluttering held in Bulgaria, May 12-14, 2007.
About the presenter: David Ward, PhD is a Lecturer and Director of the Speech Research Laboratory at the University of Reading, UK. He is both a practicing speech language therapist and a person who clutters, and currently Chairs the International Cluttering Association's academic and research committees. His personal research interests cluster around both theoretical and clinical issues in both stuttering and cluttering, and he has presented papers, published journal articles, book chapters and recently a textbook in these areas.
About the presenter: Ellen Bennett Lanouette has worked in the field for over 30 years in public school, university, and private practice settings. She received her bachelor's degree from the University of Texas at Austin, master's degree from California State University- Northridge, and Ph.D. from the University of Colorado at Boulder with an emphasis in stuttering disorders. She has co-authored numerous articles and presented many workshops at the local, state, national, and international level. In 2006, she published a comprehensive textbook focusing on the diagnosis and treatment of stuttering entitled Working with People Who Stutter: A Lifespan Approach. In 2007, she was the recipient of the NSA's Speech Language Pathologist of the Year award. Dr. Bennett Lanouette is the International Cluttering Association membership chair and currently works in the Hillsborough County Public Schools south of Tampa, Florida.


Cluttering Assessment

by Yvonne van Zaalen-op 't Hof (Netherlands),
Florence Myers (New York, USA),
David Ward (UK),
and Ellen Bennett Lanouette (Florida, USA)

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 other disorders, and particularly, 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, or at least until treatment for stuttering is underway. Also, it is important to document the possible presence of other coexisting communication, learning, or attention deficit hyperactivity disorders.

Case history

As in most speech-language evaluations, the case history should include information regarding the following aspects of development: The primary reason why the person has presented for assessment (and potentially for treatment)

      1. Birth and developmental history
      2. Medical history
      3. Onset, course, previous treatment (and efficacy of previous therapy)
      4. Family history of speech or language disorders including fluency disorders and tachylalia
      5. History of any 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).
      6. Hearing Screening

We recommend digital video and audio recording of the person who clutters in a variety of speaking tasks for subsequent analyses of fluency, rate, articulation, language, and voice. The clinician should be aware that the client may try to "normalize" speech behaviors when being recorded, by comparing client's communication behaviors when being recorded and when speaking extemporaneously when not being recorded.

Cluttering assessment should assess different tasks to include oral reading, spontaneous speech, retelling a memorized story, a test of oral motor coordination and questionnaires. Cluttering severity may vary depending on the nature of the speaking task. Cluttering behaviors are more likely to surface as the speaking task is more extemporaneous and informal, less structured, more emotional, and linguistically more complex.

Oral reading

The nature of the oral reading task will limit the possibilities for language formulation difficulties in the clutterer; however, omission of syllables and words (particularly pronouns and articles) may occur. Take note of errors in syllable and word structure such as telescoping of syllables (for example saying "spetti" for "spaghetti") or semantic paraphasias (for example saying "table" for "chair"). Because the level of reading material may influence the degree of cluttering, present clients with appropriate reading material that vary in reading difficulty. The more difficult passages, containing more multisyllabic words and linguistically more complex sentences, may produce more cluttering behaviors compared to the less difficult passages. It is also suggested that the client read a passage with and one without preparation, to compare the results.

Spontaneous speech

Engage the client in a more relaxed exchange on a subject that is of high interest to the client. This can include explaining a videogame, telling about his favorite sport or leisure activity, or telling a story about a recent exciting event that the client experienced. Record at least 10 minutes of this language sample. The language sample should consist of a narrative rather than simply repeating the events as in a list. We have found that cluttering behaviors become more evident the more informal, spontaneous and extensive the talk. When the client is not aware of the recording you will have the highest chance of recording "uncontrolled" cluttering speech. Such speech may also be observed when recording the interaction between, for instance, the parent and the child, or the adult and partner while you leave the room for awhile.


Assessment of articulation should include tasks that range from short and structured tasks, to longer and less structured tasks. Examples of the former include rote tasks such as counting or reciting memorized material. Be aware of errors in syllable- and word structure and take measures of articulatory rate. Some clutterers have sound-specific misarticulations. Most clutterers exhibit reduced (non-sound-specific) speech intelligibility as the talk becomes more informal and extended. Difficulty with speech intelligibility arises from omitting or slighting of sounds and syllables, neutralization of vowels, cluster reductions.

OMAS (Riley and Riley, 1985): Although the norms for adolescents and adults are lacking, the diadochokinetic tasks of the oral motor assessment scale (OMAS) provide clear guidelines for observation of oral motor coordination. Imitation of numbers (forward and backward) provides information of auditory memory and flexibility.


People who clutter commonly experience language deficits besides their articulatory problems. It is, therefore, important to assess the language skills of the client. Language difficulties include word-finding problems, poor syntactic structure, lack of coherence and cohesion in discourse and narratives, and compromised pragmatics (e.g., poor presuppositional skills such as not taking into account the listener's viewpoint or knowledge; frequent interruption of conversational partner's turn) in individuals who clutter. We speculate that a number of the clutterer's disfluencies are motivated by linguistic rather than motoric difficulties; these disfluencies are often called "linguistic maze" behaviors.

Computer-based Cluttering Assessment Tool

Because of the multidimensional nature of cluttering, we need to supplement assessment of the individual dimensions such as rate and fluency with a means to rate the overall severity of cluttering based on the trained clinician perception. A freeware assessment tool was developed for this purpose by Klaas Bakker, the Cluttering Assessment Program (CLASP). It is explained and available in another conference paper as well as on the International Cluttering Association website.

This assessment tool allows the clinician to determine % talking time cluttered. While listening to a speech sample, talking time is measured by pressing the left mouse of the computer when the client's speech is perceived (either fluent or cluttered). The perception of cluttering is marked by holding down the right mouse for the duration of perceived cluttering. An updated version of the SLASP is planned.


Cluttering checklists and self-assessment

Where there are questions relating to cluttering behaviors (for example, some questions on the WASSP and PSI relate to the physical aspects of disfluencies), comparisons can be made between the clinician's observations and those of the client. For instruments tapping feelings and attitudes (such as the S-24, subsections of the WASSP and the "expectancy" and "avoidance" statements on the PSI), the clinician can go through the responses together with the client once the client has completed the assessment and use the client's responses as a springboard for subsequent therapy.


Writing and reading are higher developmental stages of speech and language development. Besides linguistic weaknesses, poor handwriting is one of the earlier behaviours associated with cluttering. Some older clutterers use the compensatory strategy of printing the written code. It is suggested that clients be asked to write in both script as well as print for comparison. Writing errors may mimic difficulties in the speech domain, so ask the client to write a short paragraph, looking for untidy or illegible writing, weak spelling, poorly constructed grammar, and transposition and omissions of letters as evidence of cluttering related behaviors.

Differential diagnostics with other disorders

Cluttering usually co-exists with other disorders such as stuttering, articulation disorders, attention-deficit disorders/hyperactivity disorders and learning disabilities.

The available literature as a whole suggests that an essential difference between cluttering and stuttering lies on the speaker's level of preparedness for saying intended utterances. Stutterers know what they intend to say but are interfered at the motoric level in their attempts to produce various words, whereas clutterers do not necessarily know all of what they want to say (or how to say it) but continue talking anyway. Part-word repetitions, prolongations and blocks are typically produced by stutterers, whereas excessive but normal disfluencies often characterize the speech of clutterers. The latter include interjections, incomplete phrases/words, and revisions.

Persons who clutter exceed the normal qualitative and quantitative limits of changes in sounds and tend to delete or neutralize syllables that standard speakers do not neutralize, especially in fast speech. Although symptoms of ADD/ADHD are mentioned as cluttering, individuals diagnosed with ADHD do not necessarily clutter.

Specific Learning Difficulties have been reported to co-exist with cluttering, especially difficulties in oral expression, reading, writing, handwriting and music; however, corroborating data for these observations are anecdotal.


Analyze the recordings and questionaires and decide on rate, fluency, articulation, language and cognitive/emotional components of the disorder. Comparing the client's perspective with the clinician's perspective can enlighten the clinician regarding the client's self-awareness of the disorder.


The assessment procedures outlined above are offered as guidelines, subject to modifications as warranted by empirical data based on research.


SUBMITTED: February 17, 2010

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