SPECSYNTH

        Original          Synthesized
SPECSYNTH creates a spectrogram from a digital sound waveform, allowing copy synthesis through a tracing method. The synthesis procedure is the same as that used by SYNTH. When the program SPECSYNTH is started, it searches the contents of the working memory buffer for a variable "y" which is assumed to represent the input sound waveform. If the variable "y" does not exist, it is generated as a 200-ms segment of a "neutral" vowel similar to schwa.

Entering Data/Track Drawing

Upon starting the program, a spectrogram is generated from the user-defined waveform vector. The spectrogram is generated with a Fast Fourier Transform (FFT) method. The lines representing the formant tracks are superimposed on the spectrogram. The fundamental frequency (F0) track is estimated from the waveform by a sliding window cepstral analysis (Rabiner & Schafer, 1978). These initial fundamental frequency estimates can be refined or smoothed with the aid of the drawing functions. The overall amplitude (AV) is estimated from the waveform by computing the rms energy in a sliding rectangular window. Editing and track drawing are mouse controlled, as described for the SYNTH program.

Playback

SPECSYNTH has two playback options. The program can play the synthesized utterance, or it can play the original sound for comparison purposes.


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