The Extremal Sampling Technique

The transcription technique of the acoustic structure has been studied. The maximum and minimum data of the filtered waveform plays a key role in the abstraction of the 3-dimentional acoustic structure of time, energy and frequency. The technique has ascertained that the whole recordings collected from various radio programs comprised not only 6,769 extrema in average but also the remaining 43,250 (86.5 %) of noise level per second. The traditional sampling data with a fixed rate of 44.1 kHz included the approximated extrema within a spectral bandwidth of 40- 5,120 Hz. The conversion from a wav-formatted file to the extremal data was realized with 16.0 % reduction of the file size, preserving the semantic information.