This study examined kinematic and acoustic adaptation following the placement of electromagnetic articulography (EMA) sensors, which measure speech articulator movements. Sixteen typical native English speakers had eight EMA sensors attached to obtain kinematic data: three to the tongue (front, mid, and back at midline), one on the lower incisors (jaw), two on the lips (one on each lip at midline), and two reference sensors on the eyeglass frames worn by the participants. They repeated the same sentence stimuli 5 times every two minutes (0, 2, 4, 6 minutes post-attachment) while both acoustic and kinematic data were recorded. Global kinematic measures of tongue activity were computed using articulatory stroke metrics, while point measures were gathered from one syllable in the target sentence. The first two formant frequencies of that syllable were measured. Statistical analysis revealed several significant changes over time and differences between genders. There was a significant increase in the syllable speed and decrease in sentence duration over time. The first formant was significantly lower over time correlating with decreased hull area, representing higher tongue position and smaller movements as speakers adapted to the sensors. Tongue displacement during the syllable production decreased over time; there was not a significant gender difference for displacement measures. The number of articulatory strokes decreased over time, suggesting improved articulatory steadiness. It can be concluded that participants demonstrated faster, smaller movements over time, but it is not clear how much of the change was a result of kinematic adaptation or task familiarity. Future research is needed to compare the direct relationship between kinematic, acoustic, and perceptual measures in response to the attachment of these EMA sensors.

This thesis examined the time course of speech adaptation prior to data collection when using an electromagnetic articulograph to measure speech articulator movements. The stimulus sentence and electromagnetic sensor placement were designed to be sensitive to changes in the fricatives /s/ and /ʃ/. Twenty native English speakers read aloud stimulus sentences before the attachment of six electromagnetic sensors, immediately after attachment, and again at 5, 10, 15 and 20 minutes after attachment. Participants read aloud continuously between recordings to encourage adaptation to the presence of the sensors. Audio recordings were rated by 20 native English listeners who were not part of the production study. After listening to five practice samples, these participants rated 150 stimuli (31 repeat samples) using a visual analog scale (VAS) with the endpoints labeled as precise and imprecise. An acoustic analysis of the recordings was done by segmenting the fricatives /s/ and /ʃ/ from the longer recording and computing spectral center of gravity and spectral standard deviation in Hertz. Durations of /s/, /ʃ/ and the sentence were also measured. Results of both perceptual and acoustic analysis revealed a change in speech precision over time, with all post attachment recordings receiving lower perceptual scores. Precision ratings beyond the ten minute recording remained steady. It can be concluded from the results that participants reached a height of adaptation after 10 minutes of talking with kinematic recording sensors attached, and that after the attachment of sensors, speech production precision did not at any point return to pre attachment levels.