Discrimination of formant amplitude-change: Psychophysical change and phonemic change

Early results on synthetic-vowel formant amplitude discrimination by Flanagan [J. Acoust. Soc. Am. 27, 1223–1225 (1955); J. Speech Hear. Disord. 22, 205–212 (1957)] indicated that ΔI for overall vowel level was about ± 1.5 dB, but that ΔI for F2 was about ± 4 dB. The latter result was for F2 ≃ − 12dB re: F1 for the “comparison” vowel. Subjects made a same-different judgment which may have affected the interpretation of these results. Here we report ΔI for several “comparison” vowels which differ in amplitude relations among F1, F2, and F3. In addition, we report on perception of extreme shifts in formant amplitude, Implications for computer recognition of speech will be discussed.