Vowel Space Expansion Sensorimotor Adaptation

NCT06233513 | Recruiting

• 4 other identifiers: 2017-1128 Adaptation (Exp 1-4)Protocol Version 10/31/2021A4818001R01DC019134-01A1
• Study Type: interventional
• Target: 117
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this research study is to understand how the brain processes and controls speech in healthy people. The investigators are doing this research because it will help identify the mechanisms that allow people to perceive their own speech errors and to learn new speech sounds. 117 participants will be enrolled into this part of the study and can expect to be on study between 1 day (Experiment 1) and 4 weeks (Experiment 2).

Conditions

Speech

Keywords

speech motor control; vocal learning

Outcome Measures

Primary Outcomes (4)

• Average Vowel Spacing (AVS) Measured as the Mean of Pairwise Formant Distances Between Vowels

  AVS is a local measure of vowel spacing.

  up to 1 hour (Exp 1,3); eight visits of 1 hour each over 4 weeks (Exp 2)

• Quadrilateral Vowel Space Area (qVSA)

  qVSA measures the area (in Hz\^2) between the F1/F2 coordinates of the corner vowels. This is a global measure of working vowel space.

  up to 1 hour (Exp 1,3); eight visits of 1 hour each over 4 weeks (Exp 2)

• Intelligibility measured by Percent of words correctly identified by 5 independent transcribers

  Intelligibility is a perceptual measure. Four repetitions of each spoken production from each adaptation phase, as well as the minimal-pair neighbors from the calibration phase, will be identified by all transcribers. Because intelligibility in healthy speakers is expected to be near ceiling, speech signals will be masked by speech-shaped noise and delivered at 72 dB over closed-ear headphones. Signal-to-noise ratio will be determined prior to testing as the ratio where, on average, 50% of stimuli in the calibration phase are correctly identified. Transcribers will be native English speakers with no history of neurological/hearing disorders who pass a pure-tone hearing test.

  up to 1 hour (Exp 1,3); eight visits of 1 hour each over 4 weeks (Exp 2)

• Auditory acuity is measured as the average just noticeable difference (JND) along 4 vowel formant continua

  Auditory acuity is measured as the average just noticeable difference (JND) along 4 vowel formant continua: /i/-/ɪ/, /ɛ/-/æ/, /u/-/ʊ/, and /ɑ/-/ʌ/. Acuity will be measured at continua midpoint (across-category acuity) and at the four corner vowel endpoints (within-category acuity). JNDs will be measured through a 4-interval, 2-alternative forced choice task (AABA or ABAA) via a staircase procedure.

  up to 1 hour (Exp 1,3); eight visits of 1 hour each over 4 weeks (Exp 2)

Study Arms (1)

Healthy Adult Speakers

EXPERIMENTAL

healthy adult participants across the lifespan in three groups:18-35, 36-55, and 56+

Behavioral: Exp 3 Speaking Task

Interventions

Exp 3 Speaking Task BEHAVIORAL

Participant will sit in front of a computer screen in a quiet room and to produce speech based on what is on the screen. Participant may see real words or nonsense words to read. Investigators may play sounds through headphones and ask the participant to repeat them. Participant speech will be recorded by a microphone. This task takes about one hour to complete.

Also known as: vowel space expansion

Healthy Adult Speakers

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• English-speaking adults
• normal hearing and speech
• no history of stroke or neurological conditions

You may not qualify if:

• Native language other than English
• Any neurological disorders other than the disorder of interest
• Any history of hearing disorders
• Uncorrected vision problems that prevent participants from seeing visually-presented stimuli
• Significant cognitive impairments that prevent participants from carrying out the task or from giving informed consent
• Vulnerable populations (minors and prisoners)

Sponsors & Collaborators

• University of Wisconsin, Madison: lead
• National Institute on Deafness and Other Communication Disorders (NIDCD): collaborator

Study Sites (1)

University of Wisconsin

Madison, Wisconsin, 53705, United States

RECRUITING

Related Links

• Link to study record for experiment 7 \[NCT05723575\]
• Link to study record for experiment 5 \[NCT05286658\]

MeSH Terms

Conditions

Speech

Condition Hierarchy (Ancestors)

Verbal Behavior; Communication; Behavior

Study Officials

• Carrie Niziolek, PhD

  University of Wisconsin, Madison

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Carrie Niziolek, PhD

CONTACT

608-890-0192; cniziolek@wisc.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 22, 2024
• First Posted: January 31, 2024
• Study Start: February 15, 2024
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026
• Last Updated: April 9, 2026

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share

Locations

US (1)