Trial Outcomes & Findings for Speech Processing in Stuttering (NCT NCT04929184)
NCT ID: NCT04929184
Last Updated: 2026-07-16
Results Overview
Participants will hear a series of single syllables spoken rhythmically and will be instructed to whisper the syllable "tah" repeatedly while the recording is playing. The degree of synchronization (how well the participant's whispered syllables match the cadence of the recorded syllables they are listening to) will be measured by computing the PLV between subject's produced speech and the heard speech. The PLV is a vector with a value between 0 and 1 that reflects the phase difference between two signals, where 0 is a complete mis-match and a 1 is a perfect match. Adults were not instructed to attempt to match the cadence (Implicit task). Child participants were instructed to attempt to match the cadence (Explicit task).
COMPLETED
NA
145 participants
Session 1 (up to 4 hours)
2026-07-16
Participant Flow
145 participants were enrolled (signed consent form). 26 participants were either lost to follow up (n=15; including 2 participants between Visit 1 and Visit 2) or determined to be ineligible following enrollment (n=11).
Participant milestones
| Measure |
Adults Who Stutter (AWS)
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Adults
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Children Who Stutter (CWS)
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Children
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
|---|---|---|---|---|
|
Visit 1
STARTED
|
55
|
67
|
13
|
10
|
|
Visit 1
COMPLETED
|
45
|
53
|
13
|
10
|
|
Visit 1
NOT COMPLETED
|
10
|
14
|
0
|
0
|
|
Visit 2 (Adults only)
STARTED
|
45
|
53
|
0
|
0
|
|
Visit 2 (Adults only)
COMPLETED
|
43
|
53
|
0
|
0
|
|
Visit 2 (Adults only)
NOT COMPLETED
|
2
|
0
|
0
|
0
|
Reasons for withdrawal
| Measure |
Adults Who Stutter (AWS)
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Adults
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Children Who Stutter (CWS)
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Children
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
|---|---|---|---|---|
|
Visit 1
Lost to Follow-up
|
5
|
8
|
0
|
0
|
|
Visit 1
Determined to be ineligible
|
5
|
6
|
0
|
0
|
|
Visit 2 (Adults only)
Lost to Follow-up
|
2
|
0
|
0
|
0
|
Baseline Characteristics
Speech Processing in Stuttering
Baseline characteristics by cohort
| Measure |
Adults Who Stutter (AWS)
n=55 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Adults
n=67 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Children Who Stutter
n=13 Participants
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Children
n=10 Participants
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Total
n=145 Participants
Total of all reporting groups
|
|---|---|---|---|---|---|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=9 Participants
|
0 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
0 Participants
n=265 Participants
|
0 Participants
n=568 Participants
|
|
Race (NIH/OMB)
More than one race
|
4 Participants
n=9 Participants
|
2 Participants
n=27 Participants
|
2 Participants
n=267 Participants
|
0 Participants
n=265 Participants
|
8 Participants
n=568 Participants
|
|
Age, Continuous
|
32.1 Years
STANDARD_DEVIATION 11.2 • n=9 Participants
|
30.7 Years
STANDARD_DEVIATION 10.3 • n=27 Participants
|
9.2 Years
STANDARD_DEVIATION 1.2 • n=267 Participants
|
10.9 Years
STANDARD_DEVIATION 1.7 • n=265 Participants
|
20.7 Years
STANDARD_DEVIATION 6.1 • n=568 Participants
|
|
Sex/Gender, Customized
Male
|
39 Participants
n=9 Participants
|
40 Participants
n=27 Participants
|
9 Participants
n=267 Participants
|
7 Participants
n=265 Participants
|
95 Participants
n=568 Participants
|
|
Sex/Gender, Customized
Female
|
16 Participants
n=9 Participants
|
27 Participants
n=27 Participants
|
4 Participants
n=267 Participants
|
3 Participants
n=265 Participants
|
50 Participants
n=568 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=9 Participants
|
1 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
0 Participants
n=265 Participants
|
1 Participants
n=568 Participants
|
|
Race (NIH/OMB)
Asian
|
13 Participants
n=9 Participants
|
9 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
0 Participants
n=265 Participants
|
22 Participants
n=568 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=9 Participants
|
0 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
0 Participants
n=265 Participants
|
0 Participants
n=568 Participants
|
|
Race (NIH/OMB)
Black or African American
|
6 Participants
n=9 Participants
|
7 Participants
n=27 Participants
|
2 Participants
n=267 Participants
|
0 Participants
n=265 Participants
|
15 Participants
n=568 Participants
|
|
Race (NIH/OMB)
White
|
32 Participants
n=9 Participants
|
48 Participants
n=27 Participants
|
9 Participants
n=267 Participants
|
10 Participants
n=265 Participants
|
99 Participants
n=568 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
2 Participants
n=9 Participants
|
7 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
2 Participants
n=265 Participants
|
11 Participants
n=568 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
53 Participants
n=9 Participants
|
60 Participants
n=27 Participants
|
13 Participants
n=267 Participants
|
8 Participants
n=265 Participants
|
134 Participants
n=568 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=9 Participants
|
0 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
0 Participants
n=265 Participants
|
0 Participants
n=568 Participants
|
|
Region of Enrollment
United States
|
55 participants
n=9 Participants
|
67 participants
n=27 Participants
|
13 participants
n=267 Participants
|
10 participants
n=265 Participants
|
145 participants
n=568 Participants
|
PRIMARY outcome
Timeframe: Session 1 (up to 4 hours)Population: Adults only completed the implicit task on visit 1. Only children completed the explicit task on visit 1 (their only visit).
Participants will hear a series of single syllables spoken rhythmically and will be instructed to whisper the syllable "tah" repeatedly while the recording is playing. The degree of synchronization (how well the participant's whispered syllables match the cadence of the recorded syllables they are listening to) will be measured by computing the PLV between subject's produced speech and the heard speech. The PLV is a vector with a value between 0 and 1 that reflects the phase difference between two signals, where 0 is a complete mis-match and a 1 is a perfect match. Adults were not instructed to attempt to match the cadence (Implicit task). Child participants were instructed to attempt to match the cadence (Explicit task).
Outcome measures
| Measure |
Adults Who Stutter (AWS)
n=43 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Adults
n=51 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Children Who Stutter (CWS)
n=13 Participants
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Children
n=10 Participants
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
|---|---|---|---|---|
|
Phase Locking Value (PLV) - Session 1 Speech Tasks
Implicit
|
0.42 PLV
Standard Deviation 0.15
|
0.42 PLV
Standard Deviation 0.14
|
—
|
—
|
|
Phase Locking Value (PLV) - Session 1 Speech Tasks
Explicit
|
—
|
—
|
0.42 PLV
Standard Deviation 0.15
|
0.44 PLV
Standard Deviation 0.21
|
PRIMARY outcome
Timeframe: Session 2 (up to 4 hours)Population: Children did not complete Visit 2.
Adult participants will hear a series of single syllables spoken rhythmically and will be instructed to whisper the syllable "tah" repeatedly while the recording is playing. Child participants did not attend Session 2. The degree of synchronization (how well the participant's whispered syllables match the cadence of the recorded syllables they are listening to) will be measured by computing the PLV between subject's produced speech and the heard speech. The PLV is a vector with a value between 0 and 1 that reflects the phase difference between two signals, where 0 is a complete mis-match and a 1 is a perfect match. Adults completed this task twice. For the first test, they were not instructed to attempt to match the cadence (Implicit task). For the second test, they were instructed to attempt to match the cadence (Explicit task).
Outcome measures
| Measure |
Adults Who Stutter (AWS)
n=43 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Adults
n=51 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Children Who Stutter (CWS)
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Children
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
|---|---|---|---|---|
|
Phase Locking Value (PLV) - Session 2 Speech Tasks
Implicit
|
0.43 PLV
Standard Deviation 0.15
|
0.42 PLV
Standard Deviation 0.16
|
—
|
—
|
|
Phase Locking Value (PLV) - Session 2 Speech Tasks
Explicit
|
0.56 PLV
Standard Deviation 0.22
|
0.57 PLV
Standard Deviation 0.24
|
—
|
—
|
SECONDARY outcome
Timeframe: Session 1 (up to 4 hours)In tapping synchronization (sensorimotor synchronization) research, the R statistic generally refers to the resultant vector length derived from circular statistics, used to quantify the consistency and stability of a participant's tapping relative to a rhythmic stimulus. It ranges from 0 to 1. 0=Complete inconsistency (taps are uniformly distributed). 1=Perfect consistency (all taps occur at the exact same relative phase).
Outcome measures
| Measure |
Adults Who Stutter (AWS)
n=45 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Adults
n=53 Participants
Participants will have 2 visits.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Children Who Stutter (CWS)
n=11 Participants
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
Healthy Children
n=10 Participants
Participants will have 1 visit.
Speech and non-speech tasks: Participants will complete speech tasks such as listening to and/or producing speech and non-speech sounds.
|
|---|---|---|---|---|
|
R Statistic (Resultant Vector Length)
|
0.91 R
Standard Deviation 0.1
|
0.91 R
Standard Deviation .08
|
.08 R
Standard Deviation .02
|
.07 R
Standard Deviation .004
|
Adverse Events
Adults Who Stutter (AWS)
Healthy Adults
Children Who Stutter (CWS)
Healthy Children
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place