Abstract: A voice mail system includes method and apparatus for muting a previously recorded audio signal upon detection of a DTMF signal to differentiate between recorded DTMF signals and valid DTMF commands. A DTMF signal detected after muting is recognized as an invalid command.

Abstract: Apparatus sorts articles according to any combination of plural criteria, including volume or diameter, length, shape, weight, color, density and surface quality. A light sensitive dynamic random access memory and novel processing circuitry are utilized for providing indications of the article's volume, diameter and length.

Abstract: A method for maintaining zero calibration values representative of average tare, or average empty cup weight, in an article sorting machine of the type employing cups to sort articles by weight comprises the steps of measuring the weight of each cup, and if the cup is carrying an article, the weight of the cup and the article, passing over an electronic scale, and determining whether the cup is carrying an article based upon the value of a weight signal provided by the electronic scale. A running sum of the values of the weight signals for the cups determined not to be carrying articles is maintained. A count of the number of cups determined not to be carrying articles is also maintained. After a selected interval, the running sum is divided by the count to arrive at an updated average tare, or updated average empty cup weight.