Videofluoroscopic Investigation of Body Position on Articulatory Positioning

Abstract

The present study demonstrated that structural positioning in response to gravity varied across individuals based on the type of activities being performed. With varying degrees of positional adjustment across different structures, fairly consistent articulatory positioning in the anterior-posterior dimension was maintained in different body positions during speech.

Effect of body position on vocal tract acoustics: Acoustic pharyngometry and vowel formants

“…The significant effect of body position on VTV, specifically the PCV-APh, is comparable to the findings in several other studies (Bae et al, 2014;Jan et al, 1994;Stone et al, 2007;Sutthiprapaporn et al, 2008;Wrench et al, 2011). However, for the volumes of both the oral and pharyngeal cavities to be smaller in the supine body position makes it difficult to determine the possible effect of one cavity over the other on the acoustic measures.…”

“…The general lack of an effect of body position on the main vowel formants F1 and F2 frequencies agrees with the results of Weir et al (1993), Tiede et al (2000), Stone et al (2007), and Bae et al (2014) but not those of Shiller et al (1999). The preponderance of the formant-frequency data from acoustic studies indicates that speakers achieve a high degree of compensation for changes in gravitational orientation.…”

“…Both F1 and F2 were higher in supine than upright body position for vowel /ae/ and less reliably for /e/. In another study of F1 and F2 frequencies for the vowels /i/ /u/ and /a/, no significant differences were observed between vowels produced in upright versus supine positions by 12 subjects, although F1 frequencies tended to be higher in the supine position (Bae et al, 2014). Tiede et al (2000) reported acoustic data from two Japanese male speakers for sustained vowels (/i/ /u/ /a/ /e/ /o/) and running speech in upright and supine positions.…”

“…The results are summarized here by task: rest breathing, swallowing, and vocal tasks of speech or singing. Studies of rest breathing have shown that the supine position resulted in (1) a thicker and longer velum, along with an increase in uvular width (Pae et al, 1994;Yildirim et al, 1991), (2) a more posterior position of the velum (Bae et al, 2014;Smith and Battagel, 2004;Sutthiprapaporn et al, 2008), or (3) no significant differences in several measures of velopharyngeal structures (Kollara and Perry, 2014;Perry, 2011). For swallowing, changes in body position have been reported to affect the temporal pattern of movement (Perry et al, 2012) and velopharyngeal closing pressure (Nakayama et al, 2013).…”

“…One of the most consistent observations is that the pharyngeal (nasopharyngeal and/or oropharyngeal) cavity is smaller in the supine as opposed to the upright position during speech, as determined from APh (Jan et al, 1994), computed tomography (CT; Sutthiprapaporn et al, 2008), MRI (Engwall, 2006;Kitamura et al, 2005;Traser et al, 2014), ultrasound (Stone et al, 2007;Wrench et al, 2011), x-ray microbeam (Tiede et al, 2000), and videofluoroscopy (Bae et al, 2014). This effect can be explained by gravity pulling the tongue root posteriorly when the subject is in the supine position, thereby reducing the size of the pharynx.…”