The purpose of the current study was to gain a better understanding of speech adaptation by examining kinematic and acoustic adaptation to bite block perturbation over time. Fifteen native American English speakers (7 female, 8 male) with no history of speech, language, or hearing deficits participated in the study. Custom bite blocks were created for speakers which created a 10mm interincisal gap when inserted. Speakers produced five repetitions of the sentence, I say ahraw /ərɑ/ (as part of a larger set) prior to bite block insertion, immediately following bite block insertion, 2-mintues post insertion, 4-minutes post insertion, 6-minutes post insertion, and immediately following bite block removal. Participants’ speech was audio-recorded, and their lingual articulatory movements were measured with a Northern Digital Instruments Wave electromagnetic articulograph. The VC syllable /ɑɪs/ was analyzed kinematically from the midpoint of the /ɑɪ/ diphthong through production of /s/ using a custom Matlab application. Kinematic data were obtained via sensor coils placed in the tongue back, tongue mid, tongue front, jaw, lower lip and upper lip. Measures of displacement (mm), maximum velocity (mm/sec), and jaw contribution to the tongue and lower lip (mm) were taken during each recording. Spectral mean (Hz), standard deviation, skewness, and kurtosis were calculated for the central 50% of each /s/ production using acoustic analysis software. Kinematic analysis revealed no significant change in tongue measures upon bite block insertion or during the 6-minute adaptation period. In contrast, significant acoustic changes were observed upon bite block insertion and during the following 6 minutes, demonstrating adaptation over time. The changes observed in acoustic measures may have been a result of tongue shape changes and subsequent adaptations that were not detected via kinematic analysis. Future studies may provide further insight into the tongue’s ability to compensate for bite block perturbation by examining the relationship between mandibular positioning and tongue shape.

The current study examined the effects of bite blocks on articulatory kinematics when producing /r/ within a phrase. Participants consisted of 20 young adults (10 males, 10 females) with no speech, language or hearing disorders. Participants produced the carrier phrase, I say __ with the nonsense words /əri/ (high front vowel), /əræ/ (low front vowel), /əru/ (high back vowel), /ərɑ/ (low back vowel). A Northern Digital Instruments Wave electromagnetic articulograph measured the articulatory movements while the speaker produced the stimuli in two conditions (Pre bite block and post bite block). Bilateral bite blocks were made using Express dental putty, which is a silicone impression material, in order to create an inter-incisal gap of 10 mm. The hull area (i.e., a boundary enclosing the total distance the sensor traveled during the target phrase) of the data for each sensor (i.e., tongue back, tongue mid, tongue front, lower lip, mandibular central incisor) was calculated for the individual nonsense words /eɪərɑ/, /eɪəræ/, /eɪəri/, and /eɪəru/. Results revealed kinematic differences across vowel phrases and between genders. The hull area of the tongue and jaw were significantly different for the vowel phrases /eɪəræ/, /eɪəri/, and /eɪəru/ compared to /eɪərɑ/. The hull area for the jaw for /eɪərɑ/ was significantly larger than the other vowel phrases. The between-gender analyses showed larger hull areas for males than females. Different motor equivalent strategies for tongue movements were observed when speakers produced /eɪərɑ/ and there were individual differences in compensating for the presence of the bite block

The current study examined the effects of bite blocks on articulatory kinematics when producing diphthongs /ɑɪ/ and /ɑʊ/ within a phrase. Participants consisted of 20 young adults (10 males, 10 females) with no speech, language or hearing disorders. Participants produced the diphthongs in the carrier phrase Im an owl that hoots. A Northern Digital Instruments Wave electromagnetic articulograph measured the articulatory movements while the speaker produced the stimuli in two conditions (pre bite block insertion and post bite block insertion). Bilateral bite blocks were made using Express dental putty, which is a silicone impression material, in order to create a 10 mm inter-incisal gap. Marker distance, maximum speed, and jaw contribution to tongue movement for three sensors (tongue back, tongue mid, tongue front) were calculated for the diphthongs segmented from the carrier phrase. F1 and F2 transitions and rate were also calculated for each diphthong. Results revealed kinematic differences during diphthong production after the bite block was inserted. Tongue movements independent from the jaw increased after the bite block was inserted, especially during production of the diphthong /ɑʊ/. Bite block by gender interactions during production of the diphthong /ɑɪ/ revealed larger and faster initial movements for males. The results did not reveal any significant acoustic changes other than a longer transition duration. Kinematic adjustments were sufficient to maintain overall similar acoustic output before and after bite block insertion.

The current study examined the lingual kinematic and acoustic effects of bite blocks on vowels in a sentence context. Twenty adult native English speakers (10 male, 10 female) with no speech, language, or hearing deficits participated in the study. The corner vowels found in the sentence, The blue spot is on the black key again (i.e., /u/, /ɑ/, /æ/, /i/), were measured kinematically and acoustically immediately before and after bite block insertion. The participants' speech was audio-recorded and their lingual articulatory movements were measured with a Northern Digital Instruments Wave electromagnetic articulograph. The sensor coils were attached to three different parts on the tongue (back, middle, and front). Acoustic analysis of the vowel formants revealed that the vowel articulation index and vowel space area decreased significantly following bite block insertion. Kinematic analysis of the sensors on the tongue revealed that the kinematic vowel articulation index decreased significantly for the back and middle of the tongue but not for the front. Thus, adjustments to the position of the front of the tongue were sufficient to compensate for the bite block perturbation, while the same measures for the back and middle of the tongue were significantly affected. This was likely due to the relative independence in the movement of the front of the tongue, given its distance from the posterior point of attachment between the tongue and mandible. These findings suggest that the effects of articulatory perturbation can be more fully understood when kinematic and acoustic measures are considered together.