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.

31 lines
1.2 KiB

From text to speech: The MITalk system
INPUT OUTPUT
R4 R1
CASCADE
INPUT OUTPUT
PARALLEL
Figure 12-3: Parallel and cascade simulation of the vocal tract transfer function
dividual amplitude controls for each formant. The disadvantage is that one still
needs a parallel formant configuration for the generation of fricatives and plosive
bursts -- the vocal tract transfer function cannot be modeled adequately when the
sound source is above the larynx, so that cascade synthesizers are generally more
complex in overall structure.
A second advantage of the cascade configuration is that it is a more accurate
model of the vocal tract transfer function during the production of nonnasal
sonorants (Flanagan, 1957). It will be shown that the transfer functions of certain
vowels cannot be modeled very well by a parallel formant synthesizer. Although
not optimal, a parallel synthesizer is particularly useful for generating stimuli that
violate the normal amplitude relationships between formants, or if one wishes to
generate, e.g., single-formant patterns.
The software simulation to be described has been programmed for normal use
as a hybrid cascade/parallel synthesizer (Figure 12-4a), or alternatively for special-
126