Pitch frequency generation system in a speech synthesis system

A speech synthesis system, comprising:

• an input terminal means for accepting text code, said text code being at least a character train having spelling, accent code, and phrase code of each word;
• generating means for receiving said text code from said input terminal means and for converting said text code to thereby generate speech parameters for speech synthesis;
• an accent command generator means for receiving said accent code which is one of said speech parameters from said generating means, and for providing a train of accent commands, each accent command being defined by a start point time, an end point time, and an amplitude which define a step function;
• a phrase command generator means for receiving said phrase code which is one of said speech parameters from said generating means, and for providing a train of phrase commands, each phrase command being defined by a time and an amplitude which define an impulse function;
• an accent command buffer means for storing said accent commands;
• a phrase command buffer means for storing said phrase commands;
• an accent component calculator means coupled to said accent command buffer means for providing an output signal representing an accent component;
• a phrase component calculator means coupled to said phrase command buffer means for providing an output signal representing a phrase component;
• an adder means for providing a sum of said output signals from said accent component calculator means and said phrase component calculator means;
• means for receiving said sum provided by said adder means, and for providing fundamental frequency of voicing;
• a speech synthesizer means coupled to said means for providing said fundamental frequency and said generating means for providing synthesized speech;
• and
• an output terminal means coupled to said speech synthesizer means for providing said synthesized speech to an external circuit,
• wherein said accent component calculator means comprises at least one accent table which stores a response for a step function corresponding to at least one accent command from said accent command generator, wherein said accent component calculator means adds together step function responses stored in at least one accent table corresponding to at least one accent command received from said accent command buffer means and provides the result of the additional which is outputted as said output signal representing said accent component, and
• wherein said phrase component calculator means comprises a single phrase table for storing impulse response for a unit amplitude, and a multiplier means for providing a product of an output of said table and said amplitude of each phrase command from said phrase command generator, said product being outputted as said output signal representing said phrase component.