Abstract: Disclosed herein is a three-way call detection system and method for detecting the addition of a third party to a pre-existing telephonic connection between a first party and a second party. The system includes a meter for measuring the amplitude of a line voltage of a telephonic connection between two parties, a first filter to remove a frequency band from the line voltage, a white noise generator for generating a low level white noise signal in the removed frequency band, a coupler for combining the white noise signal with the filtered signal, to create an additive line voltage, a second filter that passes only a portion of the additive line voltage including at least a portion of the white noise signal, and a processor for monitoring the passed signal for a shift in amplitude level associated with the addition of a third party to the connection.

Abstract: Three-way call detection is an important component of correctional facility telephone equipment because it helps restrict calling access by certain persons to certain restricted telephone numbers. Various three-way call detection methods exist, but all of these implementations suffer from one major limitation-the detection accuracy is not as high as is desired by the industry. The present invention improves detection accuracy, using “steganography.” Steganography involves hiding one set of data or signals within another signal or carrier in such a way that its presence is typically imperceptible to the human ear, and potential even the originator of the carrier signal. The present invention involves a device that connects to a telephone, either at the line or the handset interfaces, and produces a known signal that is steganographically hidden within the user's normal voice signal.

Abstract: Disclosed herein is a three-way call detection system and method for detecting the addition of a third party to a pre-existing telephonic connection between a first party and a second party.

Abstract: Disclosed herein is a three-way call detection system and method for detecting the addition of a third party to a pre-existing telephonic connection between a first party and a second party. The system comprises a meter for measuring the amplitude of a line voltage of a telephonic connection between a first party and a second party.