Effects of Cued and Uncued Swallowing in Patients With Dementia

Purpose: Parameters such as bolus location at swallow onset (BLSO), stage transition duration (STD), pharyngeal transition duration (PTD), pharyngeal response duration (PRD), and pharyngeal phase duration (PPD) often vary between cued and uncued swallowing conditions. Research has demonstrated that cued swallows may offer functional benefits that mitigate pathophysiological processes. However, there are limited data assessing differences between cued and uncued swallows in disordered populations, such as dementia. The purpose of this study was to evaluate if cued swallowing alters swallowing biomechanics in patients living with dementia. Method: Through a retrospective analysis of videofluoroscopic swallow studies (VFSS), 105 swallows from 26 participants living with dementia ( M age = 81 years; 14 women) were analyzed in duplicate by blinded raters using the Analysis of Swallowing Physiology, Events, Kinematics, and Timing method. Only VFSS with at least one cued and one uncued swallow were included in the analysis. Chi-square tests were used to explore differences in BLSO. Repeated-measures analyses of variance (ANOVAs) were used to explore differences in STD, PTD, PRD, and PPD. Results: Results revealed no significant differences in BLSO between cued and uncued swallows for patients living with dementia ( p = .934). Repeated-measures ANOVAs revealed no significant differences between the two types of swallows for STD ( p = .995), PTD ( p = .864), PRD ( p = .807), or PPD ( p = .660). Conclusions: This study suggests that there may be limited benefit to providing cued swallows to individuals living with dementia. Further research should investigate if this is due to impaired cognition and/or changes in motor control to volitionally complete the cued swallow.

Kinematic and Acoustic Changes to Vowels and Diphthongs in Bite Block Speech

Purpose We examined the effect of bite block insertion (BBI) on lingual movements and formant frequencies in corner vowel and diphthong production in a sentence context. Method Twenty young adults produced the corner vowels (/u/, /ɑ/, /æ/, /i/) and the diphthong /ɑɪ/ in sentence contexts before and after BBI. An electromagnetic articulograph measured the movements of the tongue back, middle, and front. Results There were significant decreases in the acoustic vowel articulation index and vowel space area following BBI. The kinematic vowel articulation index decreased significantly for the back and middle of the tongue but not for the front. There were no significant acoustic changes post-BBI for the diphthong, other than a longer transition duration. Diphthong kinematic changes after BBI included smaller movements for the back and middle of the tongue, but not the front. Conclusions BBI led to a smaller acoustic working space for the corner vowels. The adjustments made by the front of the tongue were sufficient to compensate for the BBI perturbation in the diphthong, resulting in unchanged formant trajectories. The back and middle of the tongue were likely biomechanically restricted in their displacement by the fixation of the jaw, whereas the tongue front showed greater movement flexibility.

The consonant length contrast in Persian: Production and perception

Across languages, there is a tendency to avoid length contrasts in the most vowel-like consonant classes, such as glides or laryngeals. Such gaps could arise from the difficulty of determining where the boundary between vowel and consonant lies when the transition between them is gradual. This claim is tested in Persian (Farsi), which has length contrasts in all classes of consonants, including glides and laryngeals. Persian geminates were compared to singletons in three different speaking rates and seven different consonant classes. Geminates were found to have longer constriction intervals than singletons, and this length effect interacted with both speaking rate and manner of articulation. In one of two perception experiments, Persian speakers identified consonants as geminate or singleton in stimuli in which the constriction duration was systematically varied. The perceptual boundary between geminates and singletons was most sharply defined for obstruents and least so for laryngeals, as reflected by the breadth of the changeover region in the identification curve. In the other perception experiment, subjects identified the length class of glides differing in constriction duration and formant transition duration. Longer formant transitions led to more geminate responses and to a broader changeover interval.

Speech perception in individuals with auditory dys-synchrony: effect of lengthening of voice onset time and burst duration of speech segments

Objective:The purpose of this study was to evaluate the effect of lengthening of voice onset time and burst duration of selected speech stimuli on perception by individuals with auditory dys-synchrony. This is the second of a series of articles reporting the effect of signal enhancing strategies on speech perception by such individuals.Methods:Two experiments were conducted: (1) assessment of the ‘just-noticeable difference' for voice onset time and burst duration of speech sounds; and (2) assessment of speech identification scores when speech sounds were modified by lengthening the voice onset time and the burst duration in units of one just-noticeable difference, both in isolation and in combination with each other plus transition duration modification.Results:Lengthening of voice onset time as well as burst duration improved perception of voicing. However, the effect of voice onset time modification was greater than that of burst duration modification. Although combined lengthening of voice onset time, burst duration and transition duration resulted in improved speech perception, the improvement was less than that due to lengthening of transition duration alone.Conclusion:These results suggest that innovative speech processing strategies that enhance temporal cues may benefit individuals with auditory dys-synchrony.

Scrutinizing the role of length of residence and age of acquisition in the interlanguage pronunciation development of English /ɹ/ by late Japanese bilinguals

The current project examined whether and to what degree continued L2 input, operationalized as length of residence (LOR), and age of acquisition (AOA), defined as the first intensive exposure to the target language, can be predictive of adult Japanese learners’ production of word-initial English /ɹ/. Data were collected from 65 participants, consisting of three groups of Japanese learners of English (n = 13 for Short-, Mid-, and Long-LOR groups, respectively) and two groups of baseline speakers (n = 13 for Japanese- and English-Baseline groups, respectively). Their production of /ɹ/ was elicited via three oral tasks (i.e., word reading, sentence reading, timed picture description). Acoustic analyses were carried out along four dimensions: third formant (F3), second formant (F2), first formant (F1) frequencies, and formant transition duration. The results demonstrated that (a) all learners reached native-like proficiency with respect to the use of existing cues (F2, transition duration) within approximately one year of LOR, (b) their performance was negatively related to AOA to some degree, and (c) longer LOR was predictive of the development of the new cue (F3). These results suggest that late L2 speech sound acquisition and proficiency may be characterized by different levels of phonetic processing.

Speech perception in individuals with auditory dys-synchrony

Objective:This study aimed to evaluate the effect of lengthening the transition duration of selected speech segments upon the perception of those segments in individuals with auditory dys-synchrony.Methods:Thirty individuals with auditory dys-synchrony participated in the study, along with 30 age-matched normal hearing listeners. Eight consonant–vowel syllables were used as auditory stimuli. Two experiments were conducted. Experiment one measured the ‘just noticeable difference’ time: the smallest prolongation of the speech sound transition duration which was noticeable by the subject. In experiment two, speech sounds were modified by lengthening the transition duration by multiples of the just noticeable difference time, and subjects' speech identification scores for the modified speech sounds were assessed.Results:Subjects with auditory dys-synchrony demonstrated poor processing of temporal auditory information. Lengthening of speech sound transition duration improved these subjects' perception of both the placement and voicing features of the speech syllables used.Conclusion:These results suggest that innovative speech processing strategies which enhance temporal cues may benefit individuals with auditory dys-synchrony.