Effects of white noise masking and low pass filtering on speech kinematics

The effects of reduced auditory information on spatial and temporal parameters of speech production were investigated using cinefluorographic techniques. While subjects read a series of test words embedded in carrier sentences, they received normal auditory information, auditory information regarding only the first formant of their production, or high level noise to mask all formant information. Kinematic analyses indicated that while there were some changes across conditions, these changes were not consistent either within or across the subjects. Parameters that were affected included mean displacement, vocal tract shape, interarticulator timing, and steady state duration. The results suggest that auditory information plays a role in maintaining dynamic aspects of speech kinematics. That is, while speech can be produced without auditory information, the precise action and coordination that characteristic normal production may be altered.