Phonetics Lab., Dept. of Linguistics, UCLA, Los Angeles, CA 90024-1543
Students of speech communication need to know why a particular shape of the vocal tract has the resonances (and antiresonances) that it does. They also need to know what will happen to the formants if the vocal tract shape changes in a certain way. It is easiest to begin by studying the resonances of a neutral vocal tract. Having shown why the first three resonances of such a tube are at approximately 500, 1500, and 2500 Hz, the next step is to demonstrate the existence of nodes and antinodes in the pressure and flow waveforms. It is then possible to establish the relation between added constrictions in the vocal tract and changes in the formant frequencies, the easiest to explain being the effect of lip rounding. Another important concept is the way in which part of the vocal tract may act as a Helmholtz resonator, producing the low frequencies often associated with the first formant. All these concepts may be used in an explanation of diagrams showing the relation between formant frequencies and vocal tract shapes such as Fant's nomograms. Finally, the notion of an antiresonance may be used in an explanation of the effects of nasal coupling.
All posters will be on display and all authors will be at their posters from 3:05 to 4:20 p.m.