ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

3aSP15. A linear model of boundary shifts in /(small capital you)--(small capital eye)/ and /(open oh)--(cursive beta)/ continua.

Anna K. Nabelek

Alexandra Ovchinnikov

Dept. of Audiol. and Speech Pathol., The Univ. of Tennessee, Knoxville, TN 3796-0740

Boundary locations were tested for /(small capital you)--(small capital eye)/ and /(open oh)--(cursive beta)/ continua with steady-state or linearly changing formants in which F2 was varied. F1 and F2 trajectories had upward and downward directions. Boundary shifts were calculated for changing formant stimuli relative to the boundary for steady-state stimuli. The directions of boundary shifts indicated perceptual emphasis of the final segments of F2 trajectory which might be a consequence of low-frequency spread of masking from F1 to F2. A linear model was developed in which boundary shifts were related to spectral distance between F1 and F2 trajectories. Parameters were initial and final frequencies of F1 and boundary F2 established for each continuum with steady-state stimuli. When the distance was constant in time shifts depended on directions of F1 and F2 trajectories, described by two model terms containing differences of initial and final frequencies of F1 and F2. When the distance was changing in time additional shift was toward the greater spectral distance, described by two model terms containing ratios of initial and final frequencies. [Work supported by NIH.]