title: Resonances and wave propagation velocity in the subglottal airways.
abstract: Previous studies of subglottal resonances have reported findings based on relatively few subjects, and the relations between these resonances, subglottal anatomy, and models of subglottal acoustics are not well understood. In this study, accelerometer signals of subglottal acoustics recorded during sustained [a:] vowels of 50 adult native speakers (25 males, 25 females) of American English were analyzed. The study confirms that a simple uniform tube model of subglottal airways, closed at the glottis and open at the inferior end, is appropriate for describing subglottal resonances. The main findings of the study are (1) whereas the walls may be considered rigid in the frequency range of Sg2 and Sg3, they are yielding and resonant in the frequency range of Sg1, with a resulting ~4/3 increase in wave propagation velocity and, consequently, in the frequency of Sg1; (2) the "acoustic length" of the equivalent uniform tube varies between 18 and 23.5 cm, and is approximately equal to the height of the speaker divided by an empirically determined scaling factor; (3) trachea length can also be predicted by dividing height by another empirically determined scaling factor; and (4) differences between the subglottal resonances of males and females can be accounted for by height-related differences.
authors.affiliation: Department of Psychology, Washington University, Saint Louis, Missouri 63130, USA. slulich@wustl.edu
authors.forename: Steven M
authors.initials: SM
authors.lastname: Lulich
authors.forename: Abeer
authors.initials: A
authors.lastname: Alwan
authors.forename: Harish
authors.initials: H
authors.lastname: Arsikere
authors.forename: John R
authors.initials: JR
authors.lastname: Morton
authors.forename: Mitchell S
authors.initials: MS
authors.lastname: Sommers
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D001827:Body Height; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D010699:Phonation; D011312:Pressure; D012737:Sex Factors; D013018:Sound Spectrography; D013061:Speech Acoustics; D013997:Time Factors; D014132:Trachea / Q000033:anatomy & histology / Q000502:physiology*; D014732:Vibration; D055815:Young Adult