Effect of body position on vocal tract acoustics: Acoustic pharyngometry and vowel formants.
The anatomic basis and articulatory features of speech production are often studied with imaging studies that are typically acquired in the supine body position. It is important to determine if changes in body orientation to the gravitational field alter vocal tract dimensions and speech acoustics. The purpose of this study was to assess the effect of body position (upright versus supine) on (1) oral and pharyngeal measurements derived from acoustic pharyngometry and (2) acoustic measurements of fundamental frequency (F0) and the first four formant frequencies (F1-F4) for the quadrilateral point vowels. Data were obtained for 27 male and female participants, aged 17 to 35 yrs. Acoustic pharyngometry showed a statistically significant effect of body position on volumetric measurements, with smaller values in the supine than upright position, but no changes in length measurements. Acoustic analyses of vowels showed significantly larger values in the supine than upright position for the variables of F0, F3, and the Euclidean distance from the centroid to each corner vowel in the F1-F2-F3 space. Changes in body position affected measurements of vocal tract volume but not length. Body position also affected the aforementioned acoustic variables, but the main vowel formants were preserved.
Waisman Center, University of Wisconsin-Madison, 1500 Highland Avenue #427, Madison, Wisconsin 53711, USA.
Houri K
HK
Vorperian
Speech Pathology, Marshfield Center, 1000 North Oak Avenue, Marshfield, Wisconsin 54449, USA.
Sara L
SL
Kurtzweil
Department of Communication Sciences and Disorders, University of Wisconsin-Madison, 1975 Willow Drive, Madison, Wisconsin 53706, USA.
Marios
M
Fourakis
Waisman Center, University of Wisconsin-Madison, 1500 Highland Avenue #491, Madison, Wisconsin 53711, USA.
Ray D
RD
Kent
Waisman Center, University of Wisconsin-Madison, 1500 Highland Avenue #429, Madison, Wisconsin 53711, USA.
Katelyn K
KK
Tillman
Waisman Center, University of Wisconsin-Madison, 1500 Highland Avenue #429, Madison, Wisconsin 53711, USA.
Diane
D
Austin
D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D003308:Copying Processes; D005260:Female; D006801:Humans; D007830:Larynx / Q000502:physiology*; D008297:Male; D009055:Mouth / Q000502:physiology*; D009929:Organ Size; D010614:Pharynx / Q000502:physiology*; D010700:Phonetics; D011187:Posture / Q000502:physiology*; D012119:Respiration; D013016:Sound; D013061:Speech Acoustics; D016683:Supine Position; D014636:Valsalva Maneuver; D055815:Young Adult