A method of reproduction by a reproduction apparatus for reproducing audio documents forming part of a set of documents. After the playing of a voice mail message, an option may be provided to use the message as a reminder message. Difference circuitry determines the difference in number of pulses of the first and second pulse streams and outputs a first digital signal. The liquid waste is clarified to produce a supernatant and a sludge which is pressed into a filter cake together with the wet by-product. Packet data for multiple subscriber cable modems is easily compressed and merged over common network paths, reducing cabling plant complexity and increasing bandwidth utilization. The cleaning member has an elastic blade which indicates a 200 kgfcm2 or greater value or breaks in a tensile test at 300% elongation and a blade supporting member for supporting the elastic blade.