Correcting Residual Errors With Spectral, Ultrasound, Traditional Speech Therapy (C-RESULTS)

December 12, 2025 updated by: New York University

Correcting Residual Errors With Spectral, Ultrasound, and Traditional Speech Therapy: A Randomized Controlled Trial

Children with speech sound disorder show diminished accuracy and intelligibility in spoken communication and may thus be perceived as less capable or intelligent than peers, with negative consequences for both socioemotional and socioeconomic outcomes. While most speech errors resolve by the late school-age years, between 2-5% of speakers exhibit residual speech errors (RSE) that persist through adolescence or even adulthood, reflecting about 6 million cases in the US. Both affected children/families and speech-language pathologists (SLPs) have highlighted the critical need for research to identify more effective forms of treatment for children with RSE. In a series of single-case experimental studies, research has found that treatment incorporating technologically enhanced sensory feedback (visual-acoustic biofeedback, ultrasound biofeedback) can improve speech in individuals with RSE who have not responded to previous intervention. A randomized controlled trial (RCT) comparing traditional vs biofeedback-enhanced intervention is the essential next step to inform evidence-based decision-making for this prevalent population. Larger-scale research is also needed to understand heterogeneity across individuals in the magnitude of response to biofeedback treatment.

The overall objective of this proposal is to conduct clinical research that will guide the evidence-based management of RSE while also providing novel insights into the sensorimotor underpinnings of speech. The central hypothesis is that biofeedback will yield greater gains in speech accuracy than traditional treatment, and that individual deficit profiles will predict relative response to visual-acoustic vs ultrasound biofeedback. This study will enroll n = 118 children who misarticulate the /r/ sound, the most common type of RSE. This first component of the study will evaluate the efficacy of biofeedback relative to traditional treatment in a well-powered randomized controlled trial. Ultrasound and visual-acoustic biofeedback, which have similar evidence bases, will be represented equally.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Randomized Trial Component: Previous findings suggest that biofeedback interventions can outperform traditional speech therapy for children with RSE, but the research base to date is limited to small-scale studies that do not reach the level of evidence needed to support large-scale changes in practice. The primary objective of the C-RESULTS RCT is to test the working hypothesis that a group of individuals randomly assigned to receive biofeedback-enhanced treatment will show larger and/or faster gains in /r/ production accuracy than an equivalent group receiving the same dose of non-biofeedback treatment. To test this hypothesis, n=110 children will be randomly assigned to receive a standard course of intervention with or without biofeedback. Acoustic and perceptual measures will be used to test for differences in both short-term learning of treated targets (Acquisition) and longer-term carryover of learning to untreated contexts (Generalization). In addition, a survey assessing participants' socio-emotional well-being will be collected from caregivers both pre and post treatment.

Study Type

Interventional

Enrollment (Actual)

108

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • New Jersey
      • Bloomfield, New Jersey, United States, 07003
        • Montclair State University
    • New York
      • Syracuse, New York, United States, 13244
        • Syracuse University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

9 years to 15 years (Child)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Must be between 9;0 and 15;11 years of age at the time of enrollment.
  • Must speak English as the dominant language (i.e., must have begun learning English by age 2, per parent report).
  • Must speak a rhotic dialect of English.
  • Must pass a pure-tone hearing screening at 20 decibels Hearing Level (HL).
  • Must pass a brief examination of oral structure and function.
  • Must exhibit less than thirty percent accuracy, based on trained listener ratings, on a probe list eliciting /r/ in various phonetic contexts at the word level.

Exclusion Criteria:

  • Must not receive a T score more than 1.3 standard deviations (SD) below the mean on the Wechsler Abbreviated Scale of Intelligence-2 (WASI-2) Matrix Reasoning.
  • Must not receive a standard score below 80 on the Core Language Index of the Clinical Evaluation of Language Fundamentals-5 (CELF-5).
  • Must not exhibit voice or fluency disorder of a severity judged likely to interfere with the ability to participate in study activities.
  • Must not have an existing diagnosis of developmental disability or major neurobehavioral syndrome such as cerebral palsy, Down Syndrome, or Autism Spectrum Disorder, or major neural disorder (e.g., epilepsy, agenesis of the corpus callosum) or insult (e.g., traumatic brain injury, stroke, or tumor resection).
  • Must not show clinically significant signs of apraxia of speech or dysarthria.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group 1
Traditional articulation treatment
Behavioral: Traditional articulation treatment
Traditional articulation treatment involves providing auditory models and verbal descriptions of correct articulator placement, then cueing repetitive motor practice. Images and diagrams of the vocal tract will be used as visual aids; however, no real-time visual display of articulatory or acoustic information will be made available.
Experimental: Group 2
Biofeedback--visual-acoustic
Behavioral: Traditional articulation treatment
Traditional articulation treatment involves providing auditory models and verbal descriptions of correct articulator placement, then cueing repetitive motor practice. Images and diagrams of the vocal tract will be used as visual aids; however, no real-time visual display of articulatory or acoustic information will be made available.
Behavioral: Biofeedback--visual-acoustic
In visual-acoustic biofeedback treatment, the elements of traditional treatment (auditory models and verbal descriptions of articulator placement) are enhanced with a dynamic display of the speech signal in the form of the real-time LPC (Linear Predictive Coding) spectrum. Because correct vs incorrect productions of /r/ contrast acoustically in the frequency of the third formant (F3), participants will be cued to make their real-time LPC spectrum match a visual target characterized by a low F3 frequency. They will be encouraged to attend to the visual display while adjusting the placement of their articulators and observing how those adjustments impact F3.
Experimental: Group 3
Biofeedback-ultrasound
Behavioral: Traditional articulation treatment
Traditional articulation treatment involves providing auditory models and verbal descriptions of correct articulator placement, then cueing repetitive motor practice. Images and diagrams of the vocal tract will be used as visual aids; however, no real-time visual display of articulatory or acoustic information will be made available.
Behavioral: Biofeedback-ultrasound
In ultrasound biofeedback, the elements of traditional treatment (auditory models and verbal descriptions of articulator placement) are enhanced with a real-time ultrasound display of the shape and movements of the tongue. One or two target tongue shapes will be selected for each participant, and a trace of the selected target will be superimposed over the ultrasound screen. Participants will be cued to reshape the tongue to match this target during /r/ production.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in F3-F2 Distance (Hz) Across Sessions, Measured From /r/ Sounds Produced in Syllables or Words During Practice.
Time Frame: Phase I: three 90-min treatment sessions delivered over ~1 week; reported value is the change from Session 1 to Session 3 (slope across sessions)
F3-F2 distance is a number (in Hz) that reflects how close a child's /r/ sound is to a typical adult-like /r/. Smaller numbers indicate more accurate /r/ production; larger numbers indicate a distorted /r/. In typical peers, accurate /r/ is roughly ~500 Hz, whereas distorted /r/ values are often >1000 Hz. During Phase I (3 sessions over ~1 week), children produced /r/ in syllables/words. For this Outcome, we report change across sessions: a single model-based estimate of how much F3-F2 decreased from Session 1 to Session 3 (i.e., the rate of improvement). A more negative change indicates greater improvement.
Phase I: three 90-min treatment sessions delivered over ~1 week; reported value is the change from Session 1 to Session 3 (slope across sessions)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Pre to Post in Percent "Correct" Ratings by Untrained Listeners, for /r/ Sounds Produced in Word Probes.
Time Frame: Pre (before initiation of treatment) and Post (after the end of all treatment; ~10 weeks later).
The outcome is the percentage of untrained listeners, blinded to time point and treatment condition, who judged each /r/ production as "correct" from word-probe recordings (0-100%; higher = better). Children completed word probes at Pre and Post. Results in the table summarize change from Pre to Post using a mixed-effects model: specifically, the treatment × time interaction, which estimates the between-group difference in improvement from Pre to Post. A positive change indicates improvement.
Pre (before initiation of treatment) and Post (after the end of all treatment; ~10 weeks later).
Impact of Speech Disorder on Social, Emotional, and Academic Well-being (Parent Survey)
Time Frame: Pre (before initiation of treatment) and Post (after completion of all treatment; ~10 weeks later)
Parents completed a questionnaire assessing the impact of their child's speech disorder on social, emotional, and academic well-being. Each item was rated on a 5-point scale (1 = strongly disagree, 3 = neutral, 5 = strongly agree). Scores were averaged across items to yield an overall impact score ranging from 1 to 5, with higher values indicating a greater negative impact. A decrease from Pre to Post indicates improvement.
Pre (before initiation of treatment) and Post (after completion of all treatment; ~10 weeks later)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

New York University

Collaborators

National Institute on Deafness and Other Communication Disorders (NIDCD)
Syracuse University
Montclair State University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2019

Primary Completion (Actual)

August 31, 2024

Study Completion (Actual)

August 31, 2024

Study Registration Dates

First Submitted

October 31, 2018

First Submitted That Met QC Criteria

November 7, 2018

First Posted (Actual)

November 9, 2018

Study Record Updates

Last Update Posted (Actual)

January 5, 2026

Last Update Submitted That Met QC Criteria

December 12, 2025

Last Verified

March 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • C-RESULTS-RCT
  • R01DC017476 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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