Correcting Residual Errors With Spectral, Ultrasound, Traditional Speech Therapy

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.

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.

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.