Abstract: A method and apparatus that generate a 2100 Hz answer tone, similar to the answer tones sent by facsimile machines and modems, upon answering an incoming call. This causes predictive telemarketing dialers to remove the telephone number from their databases.

Abstract: A telephone dialer for connection to a public switched telephone network (PSTN) and to a station apparatus, for receiving digits dialed from the station apparatus and for adding digits or substituting digits for the dialed digits and for redialing digits to the PSTN wherein the redialed digits are comprised of the dialed and added digits or comprised of substituted digits, the dialer further comprising an adjustable hold circuit for connection to the PSTN during an interval when the redialed digits are being output, for holding a line associated with the PSTN in an offhook condition, the adjustable hold circuit having a load connectable to the PSTN line which is variable with PSTN line voltage at the dialer such as to draw a variable current sufficient to meet predetermined current and voltage criteria of the line at the dialer.

Abstract: A method of dialing digits using dual tone multifrequency (DTMF) signals comprised of generating a digit from a DTMF generator comprised of a first pair of signals forming a DTMF signal, one signal of the first pair of signals being in a low frequency band and one signal of the first pair of signals being in a high frequency band, and applying the DTMF signal to a telephone line connected to a central office, detecting the first pair of signals in an auxiliary circuit and immediately applying a third signal in either of the low or high bands to the telephone line at the same time as the first pair of signals, and detecting the presence of the pair of signals and the third signal at the central office and preventing processing of the DTMF signal at the central office as a result thereof.