Abstract: A circuit apparatus and a method for detecting an earphone in a portable terminal are provided. The apparatus includes an earjack, a first switch, a second switch, a comparator, and a main chip. The earjack outputs a signal informing whether an earphone is inserted, provides a signal input from a third pole of the inserted earphone to the first switch, and provides a signal input from a fourth pole to the second switch. The first switch outputs a signal provided from the earjack to one of a comparator and a ground depending on an input control signal. The second switch outputs a signal provided from the earjack to one of the comparator and the ground depending on the input control signal. The comparator compares a voltage of a signal provided from one of the first switch and the second switch with a reference voltage to output a signal representing a comparison result.

Abstract: Systems and methods for managing the volume of multiple VoIP streams are disclosed. The system includes a VoIP server configured to receive an input audio stream from a first VoIP handset, create separate output audio streams from the input audio stream for transmission to second and third VoIP handsets, and to connect to a communications network. The system also includes a volume control table coupled to the VoIP server, the volume control table including records of volume adjustments made during prior conversations between the two or more VoIP handsets. The VoIP server is further configured create the separate output audio streams such that one or more of the output streams has a volume that is different than input audio stream based on the records.

Abstract: A multi-microphone hands-free device operating in noisy surroundings implements a method of de-noising a noisy sound signal. The noisy sound signal comprises a useful speech component coming from a directional speech source and an unwanted noise component, the noise component itself including a lateral noise component that is non-steady and directional. The method operates in the frequency domain and comprises combining signals into a noisy combined signal, estimating a pseudo-steady noise component, calculating a probability of transients being present in the noisy combined signal, estimating a main arrival direction of transients, calculating a probability of speech being present on the basis of a three-dimensional spatial criterion suitable for discriminating amongst the transients between useful speech and lateral noise, and selectively reducing noise by applying a variable gain specific to each frequency band and to each time frame.

Abstract: The present invention provides a method and apparatus for finding an estimate of the delay of a signal travelling between two points. A quantity is evaluated from the signal at a final number of time instants, at both a reference point and a reception point. The values are quantized by comparison with a threshold adapted to a typical magnitude of the quantity. If the quantized values from the reception point are shifted back by the true delay with respect to the quantized values from the reference point, then certain co-occurrences of quantized values have very low probability. Hence, the best delay estimate is that shift which yields the least number of low-probability co-occurrences.

Abstract: A signal processing device includes: a speaker amplifier for amplifying a reception voice; a reception voice attenuator for attenuating the reception voice inputted to the speaker amplifier during a voice transmission mode; a reception voice detection circuit for detecting the reception voice outputted from the speaker amplifier; a microphone amplifier for amplifying a transmission voice inputted to a microphone; a transmission voice attenuator for attenuating the transmission voice outputted by the microphone amplifier during a voice reception mode; a transmission voice detection circuit for detecting the transmission voice outputted by the microphone amplifier; and a discriminator for discriminating the mode to be operated among the voice transmission mode and the voice reception mode on the basis of detection outputs from the reception voice detection circuit and the transmission voice detection circuit.

Abstract: Methods and apparatus are described for use with a near-end telephone. The near-end telephone is operable to generate an outgoing signal directed to a far-end telephone and to receive an incoming signal generated at least in part by the far-end telephone. A first signal processor is operable to dynamically adjust a first signal level associated with the outgoing signal with reference to the first signal level. A second signal processor is operable to dynamically adjust a second signal level associated with the incoming signal with reference to the second signal level. The first and second signal processors are further operable to control a loop gain to inhibit loop instability.

Abstract: The application discloses driver circuits including a current source, a current sink, and a current steering circuit configured to provide current to a load. The current sink is configured to be controlled according to a regulated voltage. Signal generator circuits are also disclosed.

Abstract: A telephone is operated in accordance with a histogram of data taken from the operation of one of its components, such as an echo cancelling circuit. The histogram provides a variable threshold for comparison with other signals or a variable control signal.

Abstract: System and method for managing routing resources for a measurement task. The system includes a computer and one or more measurement devices. The legs of a route for routing signals in performing the measurement task are created by, for each respective leg: determining if a routing resource for the respective leg is not currently used in an existing route. If not, then the resource is configured with a desired configuration of the respective leg, and a resource reservation indicated, e.g., by incrementing a resource usage count. If the resource is currently used, the desired configuration is compared with the resource's current configuration. If the current configuration conforms to the desired configuration, a resource reservation is indicated, otherwise, an error message indicating that the leg failed is returned, and optionally, an alternative leg for the route is created which includes a different resource than the respective leg. The route is stored.

Abstract: Circuit configurations designed for use with public telephones to provide standard telephone functions with higher reliability, lower cost, and lower packaging densities, include first and second channel means for providing both transmit and receive multiplexing control, a one-wire compatible user interface, and embedded PIC microcontroller for both digital control and monitoring of analog measurement and multiplexing circuits, and bitstream format conversion techniques.

Abstract: A conference call arrangement, conferencing device, conference unit and a method of managing conference calls. The conferencing device may be a speakerphone with a speak up indicator. Whenever a conference call attendee does not speak loudly enough for remote participants, the conference unit sends a speak up indication to a corresponding conferencing device.

Abstract: The present invention is directed to a telecommunication device, usable with standard telecommunication equipment, that automatically resets one or more acoustic parameters to predetermined levels prior to the initiation of the next communication session.

Abstract: A near full duplex portable handset speakerphone comprises: a microprocessor; a hands-free receive register connected to the microprocessor; a hands-free transmit register connected to the microprocessor; a ROM having a speakerphone operation algorithm, the ROM-connected to the microprocessor; a first analog-to-digital converter connected to the hands-free receive register; a second analog-to-digital converter connected to the hands-free transmit register; a first programmable digital attenuator connected to the microprocessor and to a speaker; and a second programmable digital attenuator connected to the microprocessor and to a microphone, wherein near full duplex communication is achieved without digital signal processing. In another feature of the invention, the hands-free registers provide a digital representation of the speech volume in each direction to the microprocessor.

Abstract: A method and an apparatus provide for determining whether a data terminal equipment (DTE) device represents a compatible device lacking an independent power supply and adapted to be powered using phantom power over a wired connection from a communications device such as a switch. A detection signal may be transmitted from the communications device to an identity network connected to the DTE. A response detection signal may be returned and checked in a receiver at the communications device. A switch may then be closed to provide phantom power if the result of the check indicates that the DTE is a compatible device adapted to receive phantom power. Compatible DTE device may include telephones, Voice over IP (VoIP, IP or Ethernet) telephones, network access devices, computers, and the like.

Abstract: A half duplex device and signal processing method thereof. First, a signal detection unit of a signal detector of a half duplex device obtains a short-term power and long-term power. Next, a data update unit of the signal detector sets a short-term power threshold as a default threshold, determines whether the long-term power is greater than the default threshold, sets the short-term power threshold value equal to the long-term power value if the long-term power value is greater than the default threshold value, and provides smooth performance in a noisy environment.

Abstract: The amplitudes of a signal on the microphone input of a telephone and a signal on the line input of the telephone are compared with each other and with two thresholds. The comparisons are sampled and the samples control an up-down counter. The count in the counter is compared with two thresholds and the results of the comparisons are used to control at least two accumulators. A first accumulator counts consecutive comparisons having the same result and a second accumulator counts up or down in accordance with the comparisons. The counts in the first and second accumulators are logically analyzed to determine whether to receive or transmit. A plurality of samples defines a window, at the end of which the up-down counter is reset. The accumulators store data from a plurality of windows.

Abstract: The present invention provides a digital communication system which is free from noise generated in a receiver. A transmitter converts an analog input signal to a digital signal, and then a power level detector 5 compares the digital signal with a predetermined level. In accordance with the result, the transmitter transmits a transmission signal which includes the digital signal or a digital signal amplified from that digital signal, and a control bit indicative of the result of comparison. The receiver, in accordance with the control bit included in the received digital signal, outputs an analog signal converted from the received digital signal or an analog signal converted from the received digital signal after it is digitally amplified.

Abstract: An apparatus and method are disclosed for connecting a headset microphone alternately to a telephone line and an alternative device. The apparatus includes a device connector for connecting the apparatus to the alternative device, a telephone connector for connecting the apparatus to the telephone line, and a microphone connector for connecting the apparatus to the microphone. The apparatus also includes a switching circuit connected to the device, telephone, and headset connectors. The switching circuit can be used with or included in a CTI module. The switching circuit connects the telephone connector to the headset connector in response to sensing a voltage greater than a predetermined threshold on the telephone line. When the voltage sensed returns to a value less than the predetermined threshold value, the switching circuit reconnects the headset connector to the device connector.

Abstract: Method and apparatus for detecting far end speech in a telephone apparatus. A speaker (14) produces far end sound from a far end signal, when received by the telephone apparatus. A microphone (12) generates a near end signal from near end sound, for transmission from the telephone apparatus. A hybrid (24) which passes the near and far end signals from an external two wire link (30) to and from the speaker and microphone, on respective first and second paths (1, 2) of a four wire link (28). Muting of the near end signal is effected when signal derived from the first path (1) of the four wire link (28) is detected as being representative of a condition of existence of far end signal.

Abstract: A near full duplex portable handset speakerphone comprises: a microprocessor; a hands-free receive register connected to the microprocessor; a hands-free transmit register connected to the microprocessor; a ROM having a speakerphone operation algorithm, the ROM connected to the microprocessor; a first analog-to-digital converter connected to the hands-free receive register; a second analog-to-digital converter connected to the hands-free transmit register; a first programmable digital attenuator connected to the microprocessor and to a speaker; and a second programmable digital attenuator connected to the microprocessor and to a microphone, wherein near full duplex communication is achieved without digital signal processing. In another feature of the invention, the hands-free registers provide a digital representation of the speech volume in each direction to the microprocessor.

Abstract: In a method and a device for controlling the magnitude of the generated ring signal in a the Subscriber Line Interface Circuit (SLIC) the voltage of the A and B lines to the subscriber from the SLIC is compared to a reference voltage. The device is arranged to control the magnitude of the generated ring signal voltage in response to the outcome of the comparison. In particular, the device is arranged to control the ring signal voltage so that the ring signal voltage is reduced if the voltage on the A or B line exceeds the reference voltage. Also, the reference voltage is preferably chosen so that there is no risk for saturation of the final stages. The reference voltage is preferably selected to have a value being related to the value of the negative supply voltage.

Abstract: A plurality of Goertzel filters whose operating frequencies are distributed across the voice baseband are used to detect voice and control tones in a signal. Filters operating at frequencies of control tones and detecting that most of the signal energy occurs at those frequencies indicates presence of the control tones. At least three of the filters detecting that about 10% to 20% of the signal energy occurs at each of their operating frequencies indicate presence of voice. The total energy detected in the signal being below a noise threshold indicates presence of noise or silence.

Abstract: A pet communication apparatus for allowing a user to communicate with a pet. The pet communication apparatus includes a housing member being designed for being selectively positioned on a support surface. A processing assembly is positioned in the housing member. The processing assembly is designed for being operationally coupled to a telephone jack whereby the processing assembly is operationally coupled to a telephone company. A speaker member is operationally coupled to the processing assembly whereby the speaker member is designed for audibly reproducing audio spoken by the user calling the pet. The speaker member is coupled to the housing member whereby the speaker member is designed for audibly reproducing sounds to be heard by the pet.

Abstract: A method for controlling the volume in a communication device interface unit connected to a communication device base station, where the interface unit includes a signal path for a speaker containing unit, where the input level is adjusted by a volume control and where the output is controlled simultaneously the same volume control. Also disclosed in a communication device interface unit including a first signal path for a speaker-containing unit, where the interface unit includes a volume control for manually controlling output volume, where the interface unit includes a first control circuit for controlling the level of the input to the interface unit and a second control circuit for controlling the output from the interface unit, and where the first and the second control circuits are controlled by the same volume control.

Abstract: A method and apparatus for controlling the transmit level of transmitted signals from a telephone terminal device. A gain stage applies a gain or loss to the transmit signal to adjust its signal level. The gain or loss is determined by a transmit level control module. The transmit level control module measures the transmit signal during the course of a call to determine an average signal level during active speech and the average signal level during the call is used to build a historical estimate of average signal level for the device. Following each call, a gain factor is determined based upon the historical estimate and the gain factor is used by the gain stage in setting the gain or loss applied to the transmit signal of a subsequent call. The transmit signal control module provides for an adjustment to the signal level of the transmit signal that is customized to the historical speech characteristics of the user of the device.

Abstract: A conference call arrangement, conferencing device, conference unit and a method of managing conference calls. The conferencing device may be a speakerphone with a speak up indicator. Whenever a conference call attendee does not speak loudly enough for remote participants, the conference unit sends a speak up indication to a corresponding conferencing device.

Abstract: The application discloses driver circuits including a current source, a current sink, and a current steering circuit configured to provide current to a load. The current sink is configured to be controlled according to a regulated voltage. Signal generator circuits are also disclosed.

Abstract: Methods and apparatus are described for use with a near-end telephone. The near-end telephone is operable to generate an outgoing signal directed to a far-end telephone and to receive an incoming signal generated at least in part by the far-end telephone. A first signal processor is operable to dynamically adjust a first signal level associated with the outgoing signal with reference to the first signal level. A second signal processor is operable to dynamically adjust a second signal level associated with the incoming signal with reference to the second signal level. The first and second signal processors are further operable to control a loop gain to inhibit loop instability.

Abstract: A hybrid circuit models a plurality of attributes of a communication system including a subscriber line coupled to a line interface circuit. The plurality of attributes includes subscriber line impedance, and impedance of a coupling transformer. The attributes are based on other factors, such as whether or not bridge taps exist at or near the line interface circuit on the subscriber line. The plurality of attributes are modeled by a specific arrangement of resistive and capacitive elements to substantially duplicate the collective transformative effects of the attributes on a transmission signal being sent out on the subscriber line. The transmission signal is transformed and provided to an output, where it is subtracted from a composite signal representing a combination of the actual transformed transmission signal and a receive signal. The subtraction yields an isolated receive signal, which is later processed to recover the full receive signal.

Abstract: The scope of the present invention is a device for detecting the source of a voice, which device comprises microphone means (2; 2a, 2b, 2M) for receiving a voice signal and detecting means for detecting the voice from the received voice signal. The device comprises means (15, 17) for determining the direction of arrival of the received signal, means (17) for storing the assumed direction of arrival of the voice of a certain source and means (18) for comparing the direction of arrival of said received signal with said assumed direction of arrival. The device further comprises means (18) for indicating that the source of the voice is said certain source when the comparison proves that the direction of arrival of said received signal matches with said assumed direction of arrival within a certain tolerance.

Abstract: A telephone receiving section having a final stage, an electroacoustic transducer having a first terminal connected to the ground of the circuit, a unit for controlling switching on/off, a source of a reference voltage, a switch that can adopt a first position or a second position in order to connect the second terminal of the transducer selectively, via a capacitor, to a reference-voltage terminal of the reference voltage source or to an output terminal of the final stage, respectively, and control means that respond to signals of the unit for controlling switching on/off in order to activate or to deactivate the final stage and the reference-voltage source and to operate the switch in accordance with a predetermined time program. The receiving section operates with the same immunity to disturbances as a fully balanced structure, even though the transducer is not connected between two balanced outputs.

Abstract: This invention unifies a set of statistical signal processing, neuromorphic systems, and microelectronic implementation techniques for blind separation and recovery of mixed signals. A set of architectures, frameworks, algorithms, and devices for separating, discriminating, and recovering original signal sources by processing a set of received mixtures and functions of said signals are described. The adaptation inherent in the referenced architectures, frameworks, algorithms, and devices is based on processing of the received, measured, recorded or otherwise stored signals or functions thereof. There are multiple criteria that can be used alone or in conjunction with other criteria for achieving the separation and recovery of the original signal content from the signal mixtures. The composition adopts both discrete-time and continuous-time formulations with a view towards implementations in the digital as well as the analog domains of microelectronic circuits.

Abstract: A handset port interface including DC measurement and transmit path calibration. In an interface device for interfacing a telephone instrument, such as a headset, a handset, a modem, or a teleconferencing device, to the handset microphone input port of a telephone set base unit, the transmit signal level applied to the microphone input of the base unit must be set to an appropriate level. The appropriate level is determined according to the type of microphone the telephone set base unit is configured to interface with. The microphone can be carbon, electret or dynamic. The interface device detects the type of microphone the base unit is configured to interface with by detecting the DC characteristics of the microphone input port. Then, the interface device determines the appropriate transmit level by correlating the DC characteristics to one of a plurality of predetermined transmit levels. These levels are stored in a table.

Abstract: A telephony data switching method includes receiving data from a first party and determining whether the data from the first party is substantially all speech data. If the data from the first party is ‘substantially all’ speech data, sending the data from the first party to the speaker and deactivating a data transfer state by preventing transfer of the data captured by a microphone operable to receive data from a second party and to receive data output by a speaker. If the data from the first party is not substantially all speech data, determining whether a silent data threshold has been reached. If the silent data threshold has been reached, the method also includes activating the data transfer state and recording data from the second party. If the data transfer state has been activated, the method includes sending the data from the second party to the first party.

Abstract: A voice-switching device for use in a telephone terminal which applies an optimal amount of switched loss to a plurality of distinct receive transducers. The voice-switching device detects speech signals on the transmit and receive paths to determine a mode of operation. Based on the mode of operation the device applies optimal amount of loss to the transmit path and each output path separately. This system eliminates excessive attenuation of non-dominant receive transducers as well as optimizes the transition time from active to quiescent mode for all receive transducers.

Abstract: A method of displaying alternating transmitting and receiving phases of voice communication in a mobile phone with a display when it is operated in the speakerphone mode includes the steps of comparing the intensity of a received voice signal from a caller with that of a transmitted voice signal, outputting the received voice signal through the speaker of the mobile phone while displaying a visual indication representing the receiving phase on the display if the intensity of the received voice signal is stronger than that of the transmitted voice signal, and sending the transmitted voice signal to the caller while displaying a visual indication representing the transmitting phase on the display if the intensity of the received voice signal is weaker than that of the transmitted voice signal.

Abstract: An acoustic communication terminal apparatus for performing data communication over a telephone line by using an acoustic coupler has an error number counter for counting the number of errors occurring during communication. With a control signal based on the result of this counting performed by the error number counter, the gain of an amplifier circuit provided in an acoustic output section of a transmitter portion of the apparatus is switched, and also the gain of an amplifier circuit provided in an acoustic input section of a receiver portion of the apparatus is switched. Alternatively, with the above control signal, the frequency filtering characteristics of an input filter circuit provided in the acoustic input circuit is switched.