Delineation of Sensorimotor Subtypes Underlying Residual Speech Errors
Condition: Speech Sound Disorder
MeSH terms: Speech Sound Disorder
Study type: Interventional
Phase: Phase 1

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.
    

Detailed description: 
      Single-Case Randomization Component: At the group level, speakers with RSE show poorer
      auditory and oral somatosensory acuity than typically developing (TD) speakers, but
      individuals differ in the extent to which each sensory domain is impacted. The objective of
      this aim is to evaluate how distinct sensory profiles mediate relative response to different
      types of biofeedback, with the goal of optimizing treatment through personalized learning.
      This study will test the working hypothesis that visual-acoustic biofeedback will produce
      larger gains in children whose deficit primarily affects the specification of the auditory
      target, while ultrasound biofeedback will produce larger gains in children with a primary
      somatosensory deficit. The main approach to testing this hypothesis is to select, from the
      larger population of children with RSE evaluated as part of C-RESULTS-RCT, a subset of 8
      children who show asymmetric sensory profiles (strong auditory and weak somatosensory acuity,
      or vice versa). These children will be enrolled in a single-case experimental design where
      individual treatment sessions are randomly assigned to feature visual-acoustic or ultrasound
      biofeedback. Participants will complete 20 hrs of treatment (10 days, 2 sessions per day)
      over a 5 week period. Acoustic measures will be used to evaluate /r/ production accuracy
      within each session. Randomization tests will be used to evaluate differences in accuracy
      between ultrasound and visual-acoustic biofeedback treatment conditions.
    

Intervention name(s): Visual-acoustic biofeedback; Ultrasound biofeedback
Intervention type(s): Behavioral; Behavioral
Intervention description(s): 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.
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)
Primary purpose: Treatment
Keywords: speech; articulation; motor development