A comparison of kinematic and acoustic approaches to measuring speech stability between speakers who do and do not stutter

People who stutter have been found to exhibit reduced speech stability during fluent speech production relative to people who do not stutter. One index for quantifying stability that has been applied to stuttering and non-stuttering speakers is the spatiotemporal index (STI; Smith et al., 1995). STI measures the consistency of repeated speech movements aligned using linear normalization. Similar stability indices based on nonlinear methods for alignment have also been reported (e.g., Lucero et al., 1997). Both linear and nonlinear methods have been applied to kinematic signals in previous experiments. The present study tests the possibility that measures of stability based on acoustic signals can also be useful indicators of speech stability in adults who do and do not stutter (cf. Howell et al., 2009), as using audio recordings to calculate speech variability could provide an attractive alternative for speech-language pathologists and researchers who lack access to kinematic data. In addition, both kinem...