Delineation of Sensorimotor Subtypes Underlying Residual Speech Errors
Condition: Speech Sound Disorder
MeSH terms: Speech Sound Disorder
Intervention: Visual-acoustic biofeedback; Ultrasound biofeedback
Intervention description: In visual-acoustic biofeedback treatment, the elements of traditional articulatory treatment (i.e., 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 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. I; In ultrasound biofeedback, the elements of traditional articulatory treatment 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.
Phase: Phase 1
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: In this single-case randomization design, each participant will receive an equal number of sessions of visual-acoustic and ultrasound biofeedback, with randomized allocation of treatment types to individual sessions. Treatment will last 20 hrs (10 days) over a 5 week period. Randomization will be blocked, with each day of treatment serving as a block; within each day, one hour of treatment will be randomly assigned to feature visual-acoustic and one to feature ultrasound treatment. A congruent condition and an incongruent condition will be defined for each participant based on their sensory profile, where the congruent condition is the biofeedback type that is expected to be more effective and the incongruent condition is the type expected to be less effective. Visual-acoustic biofeedback is defined as the congruent condition for individuals with a primary auditory deficit and ultrasound biofeedback is defined as congruent for individuals with a primary somatosensory deficit.
Masking: Single (Outcomes Assessor)
Masking description: All perceptual ratings will be obtained from blinded, naive listeners recruited through online crowdsourcing. Following protocols refined in previous published research, binary rating responses will be aggregated over at least 9 unique listeners per token.
Enrollment: 7.0
Sex: All
Minimum age: 9 Years
Maximum age: 15 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: speech; articulation; motor development

Summary:

      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. Further research is 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 individual deficit profiles will
      predict relative response to visual-acoustic vs ultrasound biofeedback. From the larger
      population of children with RSE evaluated as part of C-RESULTS-RCT (Correcting Residual
      Errors With Spectral, Ultrasound, Traditional Speech Therapy Randomized Controlled Trial), a
      subset of 8 children will be selected who show a deficit in one domain (auditory or
      somatosensory) and intact perception in the other. Single-case methods will be used to test
      the hypothesis that sensory deficit profiles differentially predict response to
      visual-acoustic vs ultrasound biofeedback.
    

Eligibility criteria:

        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 (dB) 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.

          -  Must show 0-5% accuracy in production of /r/ at the syllable level, based on treating
             clinicians' perceptual ratings, during an initial Dynamic Assessment phase consisting
             of 2 hours of traditional (non-biofeedback) instruction.

          -  Must fit one of two profiles: (1) primary auditory deficit (scores outside the
             normative predictive interval for auditory measures assessing identification and
             discrimination of synthetic speech stimuli, but within the normative predictive
             interval for measures of oral stereognosis and articulator placement awareness or (2)
             primary somatosensory deficit, with the reverse profile of spared/impaired sensory
             function.

        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, 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.