Method and apparatus for generating sounds with tremolo and vibrato sound effects

摘要

A digital sound generator with tremolo and vibrato sound effects is provided, which comprises: a source memory for storing different types of wave-tables; a first adder for adding a constant frequency and a step-varied frequency waveform to produce a tremulous frequency waveform; a register for storing a frequency address parameter from a central processing unit; an address generator for generating a frequency address in response to the frequency address parameter to said source memory to determine the type of signal waveform being outputted, so that said source memory produces a tremolo by playing the tremulous frequency waveform in the determined signal waveform; an amplitude generator for generating the amplitude of a normal sound; a second adder for adding the amplitude from the amplitude generator and an amplitude-variant signal from the source memory to produce a vibrato; and a synthesizer for synthesizing the tremolo and the vibrato to produce a sound with a special sound effect.