an electronic memory system and method for use in a system for reducing quantizing noise is presented . in some internet access and other dial - up services , modems or other sources connect into analog switching systems , and then are a / d - converted to reach remote switching offices . there , the digitized signal is converted back to analog , only to be re - digitized for t1 transmission . in the invention , the sample points used to re - digitize the signal are encoded using a dedicated electronic memory structure which permits efficient determination of valid data points .