Patent ID: 7572970

Claim:
A digital piano apparatus, comprising: an input unit including keys and pedals; a sound source unit that outputs tone signals corresponding to input signals supplied from the input unit; a sound field synthesizing unit that synthesizes the tone signals and outputs the synthesized tone signals; a speaker unit that outputs sound waves corresponding to the synthesized tone signals on different output channels; and speakers connected to the output channels that reproduce the sound waves, wherein the sound field synthesizing unit includes: means for generating virtual sound source location signals of a number equal to the number of output channels to reproduce a sound field for the digital piano based on the tone signals, the virtual sound source location signals corresponding to sounds of a reference piano from different locations about the reference piano, the means for generating virtual sound source location signals including delay means for calculating distances and angles between the locations and the speakers, and for delaying the tone signals based on the calculated distances and angles; means for mixing the virtual sound source location signals; and means for applying a sound effect, by signal processing using impulse responses, to the mixed sound source location signals.