An interventional study of AAC Speech supplementation in Cerebral Palsy (CP), Intelligibility, Speech and Augmentative and Alternative Communication, sponsored by University of Wisconsin, Madison. Recruiting at 1 site in United States. Open to participants aged 7 Years to 17 Years. Per ClinicalTrials.gov, last updated 2026-08-03.
Sponsored by University of Wisconsin, Madison · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to learn if speech supplementation can improve speech intelligibility in children ages 7 to 17 years with cerebral palsy. The main questions it aims to answer are:
Participants will:
This study uses a pre-/post- test design to test the effects of a one-session intervention to improve speech intelligibility in 100 children with cerebral palsy and dysarthria. The intervention involves the augmentative and alternative communication (AAC) strategy known as speech supplementation. Specifically, children will learn how to simultaneously speak and point to the first letter of each word on a communication board, or to speak and point to a topical picture on a communication board. The strategy serves to provide listeners with context cues for spoken words, and it also serves to impact temporo-acoustic features of speech by reducing rate of speech and making word boundaries clear.
In this study, children will first participate in a set of baseline assessment measures, which will include the production of a corpus of 60 sentences (referred to as "habitual speech"). Then, children will learn to use the speech supplementation strategy through one-on-one clinician modeling, teaching, and practice. When children have mastered the strategy on a set of practice sentences, they will complete a post-test in which they produce the same set of elicited sentences a second time using speech supplementation.
Pre-test and post-test speech samples will then be played to two groups of listeners. One group will orthographically transcribe the words produced by children in both conditions (habitual and supplemented). Listener transcriptions in each condition will be scored as correct or incorrect based on whether they matched the intended word. Average percent of words identified correctly will be obtained from 2 listener for each child and each speaking condition as measures of speech intelligibility. The difference between habitual speech (pre-test) and supplemented speech (post-test) will be examined to quantify the effects of the speech supplementation on intelligibility.
The second set of listeners will hear the same speech samples as the first set (habitual speech and supplemented speech), but they will make ratings of whether one of the conditions seems more understandable than the other, and if so, they will rate how much better using a 7-point Likert scale.
These two sets of data from listeners will enable us to measure the minimum detectable difference in speech intelligibility and then the minimal clinically important difference based on listener ratings. Together these measures will enable us to determine how much change in intelligibility is necessary in order for clinically meaningful improvement.
The hypotheses are as follows:
1,936 studies on the registry are indexed under Cerebral Palsy; 458 are open to participants now.
This study's planned enrollment of 100 is above the median of 34 across 1,431 interventional studies indexed under Cerebral Palsy.
Browse Cerebral Palsy studies →University of Wisconsin, Madison is the lead sponsor of 1,188 studies on the registry; 181 are open to participants now.
Of its 157 completed or terminated interventional studies of FDA-regulated products, 118 (75%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Children will complete a pre-test on their speech prior to learning speech supplementation strategy use, and will be taught to use speech supplementation through one-on-one teaching. They will then complete a post test on their speech while using speech supplementation.
Behavioral: AAC Speech supplementation
The speech supplementation intervention involves learning to point to pictures, words, or letters on a communication board while simultaneously producing speech. Children will spend up to 30 minutes learning to use the strategy in one- on-one interaction with a speech therapist and demonstrate mastery by using the strategy successfully on a series of test stimuli.
Change in speech intelligibility scores from pre- to post- intervention as measured by listener transcription of speech samples
Quantify the change in speech intelligibility associated with the use of speech supplementation strategies by having listeners orthographically transcribe speech samples. Intelligibility scores are percentage calculations of the number of words identified correctly by listeners, ranging from 0 to 100 percent. Higher percentages reflect greater intelligibility, or a better understanding of what the speaker said by naive listeners.
Time frame: Before and after intervention within one session in a single day 1
Perceived change in intelligibility from pre- to post-intervention as measured by listener ratings of the magnitude of difference between pre- and post- intervention speech samples.
Listener ratings of their perception of the magnitude of change in intelligibility between pre- and post-test speaking conditions. Listeners will hear pre- and post-intervention speech samples and will indicate whether they can hear a differences and if so, how large the differences was using a 5-point likert rating scale. Higher values on the scale reflect larger perceived differences.
Time frame: Before and after intervention within one session in a single day 1
Exploratory: Change in speech rate from pre- to post- intervention as measured by difference in words per minute produced between pre- and post- intervention speech samples
The duration of each utterance produced, inclusive of pauses, will be measured as the total time between the onset of the first word and the offset of the last word. The number of words in each utterance will be divided by the utterance duration, which will be averaged across all utterances pre- intervention and post- intervention at the child level.
Time frame: Before and after intervention within one session in a single day 1
Exploratory: Change in intelligibility between pre- and post-speaking conditions for children based on severity of pre-test intelligibility impairment.
Children will be divided into severity groups based on intelligibility scores obtained in pre-test condition. Three severity groups will be operationally defined: mild, moderate, and severe. The investigators will complete analyses of differences in treatment effects for children in the different severity groups to determine if the treatment is more effective for some severity groups than others.
Time frame: Before and after intervention within one session in a single day 1
Plan to share: Yes — Individual participant data collected during the trial, after deidentification.
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: Beginning 9 months after publication of primary outcomes, and ending 5 years after that date.
Access criteria: Data will be shared with researchers whose proposed use of the data has been approved by an independent review committee identified for this purpose. Data will be shared for the following types of analyses: Independent verification of study outcomes or to conduct subsequent clinical research. Proposals should be directed to kchustad@wisc.edu. If approved after review by regulatory counsel, requestors will enter into a formal data sharing agreement. Data will be shared via encrypted single-user file transmission protocol.
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