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US 4,633,500 AGranted
Speech synthesizer
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsNorimasa Yamada, Masahiro Hibino
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Abstract
A speech synthesizer includes a lattice-type multi-stage digital filter modified in the next to last stage thereof by incorporating an increasing circuit for slightly effectively increasing the absolute value of a parameter K.sub.2 so as to reduce an attenuation factor. The device is useful for generating tones of a sustained quality, such as musical tones.
Claims6
A partial auto correlation type speech synthesizer, comprising;
- a lattice-type multi-stage digital filter which comprises a digital tone source signal generating circuit, an adder/subtractor, a delay unit and a multiplier, for extracting a predetermined frequency spectrum component from a exciting signal, and an increasing circuit for slightly increasing the absolute value of a multiplication result for a coefficient K parameter multiplier in a predetermined state of said lattice-type multistage filter, for synthesizing and outputting a sustained sinusoidal waveform or a damped oscillation waveform of long attenuation time.
Dependencies are inferred from the claim text.