Abstract
The maximum and minimum information of the acoustic waveform plays a key role in the reproduction of sound, maintaining the pitch, loudness and timbre. We have estimated the margin of error of the extrema, which would facilitate not only the visualization but also the operation of the acoustic structue. The sampled extrema were manipulated by the three steps of ±20%, ±40% and ±60% of amplitude errors and more three steps of ±4%, ±9% and ±14% of phase errors. The subjective scores have determined that the margin of error of the extrema exceeded ±20% for amplitude and ±4% for phase. The results have supported the idea that the great many resources of the wav-formatted file could be converted the temporal series of the approximated extrema under the spectral constraint of 80-5, 120Hz. Additionally, the proposed file format with variable-length record has attained the memory reduction of 54.9% for the speech data, 63.8% for the classical music, and 47.2% for the mechanical noise of doors slamming.
