抄録
The transcription technique of the acoustic structure has been studied, by modifying the conventional sampling methodology. The maximum and minimum data of the acoustic waveform play a key role in the reproduction of sound, maintaining the pitch, loudness and timbre. The acoustic structure has been simply modeled, in which ten partial sums of the Fourier series representing the audible sound. Because one of the partial sums seems like a zigzag curve, a virtual acoustic particle with energy has been assumed between the two successive extrema, hypothesizing that the monotonous curve between the two was not perceptible. The model has been evaluated by both the sum squared error and the reduction of the data size by the removal operation of a series of acoustic particles with trivial energy, without an apriori knowledge or the technique of the provisional threshold. Consequently, the extremal sampling technique at the passing bandwidth of 80 to 5,120Hz is approximately equivalent to the conventional sampling with less than 1% of the sum squared error, and has an advantage of the analysis of noise structure with 3.6% reduction of the speech data size and 1.3% for even more complex speech accompanying music.
