Abstract: A line conditioner system is provided for use with an in-line wire terminating base for terminating a plurality of telephone line pairs. The line conditioner system includes an electrical grounding, earthing bar and an integral module for conditioning a single telephone line pair. The electrical grounding, earthing bar extends along the length of the in-line wire terminating base and includes a pair of electrical grounding terminals received in electrical and mechanical contact engagement with an electrical grounding member of the in-line wire terminating base. The electrical grounding, earthing bar includes an elongated straight plate portion extending between the pair of electrical grounding terminals. The electrical grounding earthing bar is configured for easy assemble, manufacture and cleanability. The integral module includes a printed wiring board carrying protection circuitry for conditioning the single telephone line pair.

Abstract: An echo canceling loudspeaker telephone includes a loudspeaker which produces a sound pressure wave in response to an input signal which is applied to an audio input thereof. This sound pressure wave includes a desired linear component which is a linear function of the input signal, and an undesired non-linear component which is a non-linear function of the input signal, and the sound pressure wave is transmitted along an acoustic path. A microphone is positioned in the acoustic path and converts the sound pressure wave into an output signal. An echo filter is responsive to the input signal and generates an estimated echo signal. This echo filter includes a loudspeaker model which generates an estimate of the sound pressure wave including an estimate of the linear component and an estimate of the non-linear component. This echo filter also includes an acoustic path model which generates an estimate of the acoustic path from the loudspeaker to the microphone.

Abstract: An audio signal processor (209) comprises a forward signal path (256) having a forward audio signal (257) coupled to a loudspeaker (203) for producing a first acoustic signal (263), and a reverse signal path (248) coupled to a microphone (201) for producing a reverse audio signal (243), wherein at least a portion of the first acoustic signal (263) is coupled to the microphone (201) for producing a feedback audio signal (337) on the reverse signal path (248). An attenuator (305), coupled to the microphone (201), attenuates the reverse audio signal (243) responsive to a measure of the feedback audio signal (339). The measure of the feedback audio signal (339) preferrably comprises a signal to noise ratio measurement of the feedback audio signal (337). The attenuator (305) is further responsive to at least one of the first audio signal (257), and a third audio signal (239) which may also be coupled to the reverse signal path (248).

Abstract: A speech circuit is disclosed which solves the serious problem of the degradation of the articulation of received speech voice in conventional circuits and permits pleasant communications at places where the background noise level is high. The circuit has a construction in which an input signal from a microphone is attenuated in correspondence to the background noise level to form a sidetone signal and a received speech signal from a speech channel is amplified in correspondence to the background noise level to form a new received speech signal.

Abstract: A method of detecting voice in an audio signal comprises the steps of determining an average peak value representing an envelope of the audio signal, determining a running instance of audio signal standard deviation, which corresponds to one of a number of overlapping time intervals, and updating a power density function (PDF) by adding instances of noise to the PDF if the average peak of the audio signal exceeds the current level of the audio signal by a certain amount and if the current standard deviation value falls below a threshold for a predetermined time interval. A noise floor is located based on the mean value of the PDF, and, if the audio signal sustains a power level exceeding the noise floor, voice activity is determined to be present in the audio signal.

Abstract: A power conservation system for a modem in a computer system having a primary power supply and an auxiliary power supply, including a ring detect circuit coupled to a telephone ring signal line for generating a ring detect signal in response to detection of a ring signal on the telephone ring signal line, a power management system having an input coupled to the ring detect circuit and an output coupled to the primary power supply, the power management system being responsive to the ring detect signal for switching the primary power supply from a first level corresponding to a power conservation mode of operation of the computer system to a second level corresponding to a normal mode of operation, wherein the auxiliary power supply is coupled to the ring detect circuit for supplying power thereto when the computer system is in the power conservation mode of operation, whereby the ring detect circuit is maintained in an active state even during the power conservation mode of operation of the computer system.

Abstract: A peripheral platform, such as an Intelligent Peripheral (IP), is a network subsystem for use in the Advanced Intelligent Network (AIN). The IP will assume some functions presently performed by the Integrated Service Control Point (ISCP) and central office switches. In an integrated network offering interactive broadband services as well as voice telephone services, the IP also performs gateway and/or server functions for broadband communications. Among its functional capabilities will be voice announcement and digit collection. The IP also offers speech recognition capabilities and an array of other enhanced telephone call processing features, such as voice or facsimile messaging. The peripheral platform or IP will be a separate network component that will communicate with the ISCP, which controls the AIN, through a data communication network that in the preferred embodiments is distinct from the telephone company switching offices, trunk networks and any associated interoffice signalling network.

Abstract: A CPE such as an ISDN telephone subset or multimedia equipment includes an interface recognition unit that connects to the network interface and adapts itself to allow the CPE to be used with standard ISDN interfaces and an analog interface. The interface recognition unit includes an interface recognition switch (IRS) that performs two functions. First, the IRS protects the CPE from damage in those instances where a non-standard network interface is connected to the CPE. Second, for standard interfaces, it identifies the type of network interface and routes the incoming signals appropriately. Specifically, if the IRS detects a T interface, the incoming signals are switched directly to a T interface circuit for controlling and powering the higher functions of the CPE. If the IRS detects a U interface, incoming signals are automatically switched to a U interface circuit for controlling and powering the CPE.

Abstract: A method of adaptive echo cancellation finds application for example in the hands-free facilities of telecommunications terminals, to compensate for disturbing echoes from the acoustic feedback between loudspeaker (1) and microphone (2). It is known to simulate these echoes (h(k)) with digital filters, and to subtract them from the echo-affected microphone signal (z(k)). The realization usually requires a signal processor with a high operating speed, a floating point logic and a large memory space. The task is to present a cost-effective method, which can be used under different acoustic conditions. The invention fulfills this task by using a known FIR filter (5), whose filter coefficients (c.sub.1 to c.sub.N) are determined according to the NLMS algorithm. The step width (.alpha.), which determines the changing speed of the filter coefficients (c.sub.1 to c.sub.

Abstract: An ISDN interface unit interconnects a data processing unit, an ISDN, and an analog telephone and includes a ring sound controller for supplying a control signal to designate a generation of a ring of the analog telephone through a modular jack; a ring signal generator generating a ring sound; a switch selecting one of the ring sounds generated and supplying the ring sound to the analog telephone. Further, the ISDN interface unit comprises communication functions for the digital signal and for the voice band signal, a control channel signal sent from the ISDN line is interpreted, and one of the communication functions can be selected.

Abstract: A multi-variate system having a microprocessor-based telecommunications interface which has a digital adaptive all-pass filter and automatically variable delay distortion equalization circuitry which in combination provide both pre and post delay distortion equalization on the transmit and receive sides of bidirectional data lines (or dedicated telephone lines), which interfaces a conventional 4-wire analog facility and a data station termination at the customer premises equipment. A method of practicing the preferred embodiment of the invention is also disclosed.

Abstract: An echo compensation device, having a digital transverse filter, for an information transmission system is described, as well as a 4/2-wire interface having at least one such device. Accordingly, a scale value device is provided which respectively evaluates the value of the input signal and also the values of the time-delayed signals of the transverse filter and establishes a scale value as a function thereof. Furthermore, a device is provided for scaling all the signal values with the associated scale value before these are weighted with the respectively assigned filter coefficients. After addition of the weighted scaled signal values has been performed, the value of the output signal is descaled with the same scale value with which the signal values had previously been scaled.

Abstract: A telephone ring detector detects a ring signal voltage from a diverse set of signals transmitted on a telephone line before a complete alternating current ring signal cycle is received. In an exemplary embodiment, the ring detector includes a voltage threshold setting device for establishing a voltage threshold and comparing the ring signal voltage to the voltage threshold to provide an output signal when the ring signal voltage is above the voltage threshold. A pair of zener diodes having a selected voltage value can provide the threshold setting and comparison functions. A microprocessor, including a timer for measuring a time duration of the output signal, outputs a ring detection signal when the time duration exceeds a predetermined time interval value, which is substantially less than a full ring cycle. A line switch responsive to the ring detector is provided to direct communication signals to a telecommunications device.

Abstract: A telephone headset interface circuit is coupled to a telephone line to extract power for use by a headset amplifier and is particularly adapted for use with telephone handsets having dynamic or electret microphones. The telephone line connects a telephone to a service system, such as a Central Office, a PBX system, or a Key system. The interface circuit includes a power extraction circuit having a plurality of circuit portions, each one coupled to a corresponding one of the telephone line wires for providing a predetermined output voltage, so that substantially identical electrical impedance characteristics are introduced to each such wire.

Abstract: The forward signal is submitted to a finite-impulse-response linear-prediction filter in order to determine a first residual signal of minimal energy. The return signal is submitted to a finite-impulse-response filter the coefficients of which are the same as those of the linear-prediction filter of the forward signal in order to determine a second residual signal. The ratio of the energies contained in the first and second residual signals is calculated. It is determined whether the return signal contains components other than the echo components from the forward signal by comparing the calculated ratio to a detection threshold.