| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for estimating notes of multi chords from variation of an amplitude and variation of a frequency in time-based waveforms of filter outputs using a cascade connection comb-line filter system in order to estimate each note with high accuracy about the multi chords with four chords or more. <P>SOLUTION: In processing multi chords of a real musical instrument sound through a cascade connection comb-line filter system, not only an input-output amplitude ratio but also an input-output frequency ratio are noted. A corresponding pitch name is estimated from the comb-line filter showing a large variation point of the frequency ratio, further, the order of the comb-line filter is made to vary so as to correspond to each octave to estimate the octave of the sound from the amplitude change or frequency change of the output waveform, and the note of one sound among the multi chords can be estimated. Next, the comb-line filter corresponding to the estimated one sound is shifted to the head of the filter system. By repeating this operation, all the notes are estimated. <P>COPYRIGHT: (C)2008,JPO&INPIT |
