As demonstrated by the a in rain, voiced sounds have a periodic time domain waveform, shown in (a), and a frequency spectrum that is a series of regularly spaced harmonics, shown in (b).
In comparison, the s in storm, shows that fricatives have a noisy time domain signal, as in (c), and a noisy spectrum, displayed in (d).
This is because most multiplications that cost in adaptive filter is consumed by calculating the coefficients.
Acoustic echo cancellation (AEC) experiments indicate that the scheme proposed in this paper performs significantly better than traditional algorithms.
This is also the basis for the ) method of speech compression.Because the acoustic cavities have dimensions of several centimeters, the frequency response is primarily a series of resonances in the kilohertz range.In the jargon of audio processing, these resonance peaks are called the .The audio signal is broken into short segments, say 2 to 40 milliseconds, and the FFT used to find the frequency spectrum of each segment.These spectra are placed side-by-side, and converted into a grayscale image (low amplitude becomes light, and high amplitude becomes dark).
When the environment is varying, the rate is increased, while it would be decreased when the environment is stable.