Articulatory response to delayed and real-time feedback based on regional tongue displacements

Speech is one of the most complex motor tasks, due to its rapid timing and necessary precision. The difficulty of measuring articulatory movement in real time has made it difficult to investigate motion-based biofeedback for speech. Previously, we demonstrated the use of an automatic measure of tongue movement accuracy from ultrasound imaging. Using this measure for articulatory biofeedback in a simplified, game-like display may benefit the learning of speech movement patterns. To better understand real-time articulatory biofeedback and improve the design of this display, this study presented articulatory biofeedback for the target word /ɑr/ (“are”) in a game with two conditions for feedback timing (delayed and concurrent, indicating whether the game object started moving after or during speech production) and for difficulty level (easy and hard target width, indicating the articulatory precision necessary for achieving the target). For each participant, two blocks of biofeedback for 20–50 productions were presented (randomizing whether the delayed or concurrent block was presented first) in one collection session, with the difficulty level randomized for each production within each block. Data from nine children with typical speech or residual speech sound disorder were analyzed, showing that response and preference of feedback condition vary among individuals.