The kind of compreSSion often applied to a Sound waveform. Logarithmic compreSSion iS a good match for the human ear' SSenSitivity but cannot handle zero amplitude (for which the logarithm iS negative infinity). There are two Standard compreSSion functionS which give a Smooth tranSition between the logarithmic function and a linear Segment paSSing through the origin: mu-law (North America) and A-law (ITU-T). (1995-02-21)