Speaking with a bite-block: Data and modeling

Based on the assumption that the goals of phonemic speech movements are both auditory and somatosensory in nature, a biomechanical model of the vocal tract in conjunction with an adaptive controller inspired by the DIVA model of speech production (Guenther et al., 2006) were employed to investigate how the feedforward and feedback mechanisms operate in the planning for the production of the vowel [iy] with the presence of a bite-block and/or masking noise. Simulations of the vocal tract model corroborate the hypotheses predicted by the DIVA model, suggesting that: a) in the absence of auditory feedback, the subject used his learned feedforward motor command for producing a vowel-to-vowel sequence; b) in the presence of a bite-block and auditory feedback, the subject relied on the acoustic feedback mechanism during his productions; c) in the absence of auditory feedback and with a biteblock present, the subject relied on his feedforward motor plans initially, and then later on, incorporated corrective commands from the somatosensory feedback system into his productions.