C. J. Darwin
Gregory Sandell
Lab. of Exp. Psychol., Univ. of Sussex, Brighton BN1 9QG, UK
When a single harmonic close to the first formant frequency is mistuned by about 8%, that harmonic makes a reduced contribution to the vowel's first formant frequency as measured by a shift in the phoneme boundary along an F1 continuum between /I/ and /e/ [C. J. Darwin and R. B. Gardner, J. Acoust. Soc. Am. 79, 838--845 (1986)]. In the present experiment phoneme boundaries along an /I/-/e/ continuum were measured for vowels differing in F1 whose fourth harmonic (500 Hz) was mistuned by 0, (plus or minus)3, (plus or minus)6 or (plus or minus)9%. All the harmonics of a vowel (including the mistuned one) were given either no FM or coherent FM at a rate of 6 Hz and modulation depth (plus or minus)5%. The results replicated the previous findings, but found little evidence for coherent FM preventing the segregation of the mistuned harmonic from the vowel. [Work supported by SERC.]