Quantification of pharyngeal articulations using measurements from laryngoscopic images

One difficulty in the physical observation of articulatory structures in the pharynx is the reliability of measurements for comparative purposes. The objective of the present approach is to review and explore techniques of identifying and measuring degrees of adjustment of the pharyngeal articulatory mechanism in the production of auditorily controlled settings. Anatomical landmarks are identified on computer images transferred from laryngoscopic videotapes, and measurements are taken of dimensions defined by the configuration of the pharyngeal articulators. Comparisons are taken across linguistically contrastive consonants and vowels, where the activity of the laryngeal sphincter accompanies tongue retraction and larynx raising, and implications are drawn for the measurement of voice quality settings. Measurements of the “tense,” raised-larynx series of Yi (Nosu) are illustrated. 1. PHARYNGEAL ARTICULATIONS Many kinds of measurements have been made of the shape and size of the vocal tract under different phonetic conditions. This report is intended to point out an area of the vocal tract where measurement continues to be a challenge, and to present some videolaryngoscopic data which illustrate the kinds of articulations that should be considered when evaluating vocal tract volume or articulator configuration quantitatively. The aspect of speech production which we are interested in is the behaviour of the articulators in the pharynx, as observed with a fibreoptic laryngoscope. Catford [1,2,3], Gauffin [4], Kodzasov [5], Painter [6], and Esling [7] describe the auditory phonetic distinctions and articulatory parameters which define the sounds the pharynx is capable of producing. These analyses isolate stop, fricative, approximant and trill manners of pharyngeal (often called epiglottal) articulation. Traill’s research identifies “sphincteric phonation” (trilling of the aryepiglottic "laryngeal sphincter" mechanism) as a phonatory phenomenon, demonstrating the importance of considering the effects of the laryngeal sphincter on glottal phonation type [8].