You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

49 lines
1.5 KiB

The phonetic component
60r
BEFORE FRONT VOWELS BEFORE FRONT VOWELS BEFORE FRONT VOWELS
40 [ f%
(dfl)
(dB)
o B
(dB)
R
60
BEFORE BACK UNROUNDED VOWELS
40
&
3
zofi\/i%i
%12 3 & %
0 I 2 4
-FREQ (kHz) FREQ (kH2) FREQ (k?-(z) s
(e8] [oo] )
Figure 11-3: Linear prediction of plosive bursts before vowels
11.2.2 Synthesis strategy
A possible synthesis strategy for predicting formant frequency motions in CV syll-
ables is illustrated in Figure 11-5 for the syllable go. The vowel is first defined in
terms of straight-line segments. Then the formant values associated with the con-
sonant and the consonant-vowel transition are imposed, again using straight-line
segments and a locus theory equation to determine formant values at the CV
boundary. Formant motions associated with the vowel are defined in the upper
panel. Perturbations imposed by the initial consonant are indicated in the lower
panel.
Many of the remaining synthesis parameters, such as formant bandwidths and
formant amplitudes in frication spectra, must be determined by trial-and-error
comparisons of synthetic and natural linear prediction spectra. These adjustments
took several iterations. Experience showed that small errors in frication spectra, or
frication level, or the time course of intensity buildup, would result in an increased
identification error rate, so that the tedious trial-and-error optimization of these
parameters is important. The resulting control parameter values are tied to a par-
113