| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 381940500 | Soft switching, muting, or noise gating | 60 |
| 20080240464 | METHOD FOR OUTPUTTING AUDIO SIGNALS AND AUDIO DECODER - Method for outputting an audio signal to an audio output, comprising outputting a first audio signal to said audio output; providing a second audio signal; determining a point in time, wherein at said point in time said first audio signal or a derivative of said first audio signal or a derivative of said second audio signal is essentially equal to zero; switching, at said point in time, said audio output from outputting said first audio signal to outputting said second audio signal. | 10-02-2008 |
| 20080310651 | CIRCUIT AND METHOD FOR ELIMINATING SPEAKER CRACKLE DURING TURNING ON OR OFF POWER AMPLIFIER - The present invention discloses a circuit for eliminating speaker crackle during turning on or off a power amplifier and a method for the same, particularly to a circuit and method, wherein an input capacitor is used to pre-charge an output capacitor to reduce speaker crackle to an inaudible level during turning on or off a power amplifier. The present invention has a low cost and a simplified design without the penalty of bandwidth. | 12-18-2008 |
| 20090010453 | INTELLIGENT GRADIENT NOISE REDUCTION SYSTEM - An intelligent noise reduction system ( | 01-08-2009 |
| 20090010454 | INTEGRATED CIRCUIT DEVICE AND AUDIO SYSTEM - An n-channel integrated circuit device (n is an integer of 1 or greater) for muting an audio signal includes a control circuit configured to generate a control signal and a delayed control signal, a charging and discharging circuit configured to charge and discharge a time constant control terminal according to the control signal and the delayed control signal, an N-th voltage-to-current converting circuit (N is an integer from 1 to n) configured to generate a (2N−1)-th current corresponding to a voltage on the time constant control terminal and a (2N)-th current corresponding to an intermediate voltage, a (2N−1)-th mirror circuit configured to copy the (2N−1)-th current to generate (4N−3)-th and (4N−2)-th intermediate currents, a (2N)-th mirror circuit configured to copy the (2N)-th current to generate (4N−1)-th and (4N)-th intermediate currents, a (2N−1)-th selecting and combining circuit configured to combine a (2N−1)-th mute control current using the (4N−3)-th intermediate current and the (4N−1)-th intermediate current, and a (2N)-th selecting and combining circuit configured to combine a (2N)-th mute control current using the (4N−2)-th intermediate current and the (4N)-th intermediate current. | 01-08-2009 |
| 20090041264 | SOUND SIGNAL PROCESSING APPARATUS - An audio signal processing apparatus for outputting an input digital audio signal as a positive phase PWM signal and a negative phase PWM signal. The resolution of the input digital audio signal is converted to a low resolution and noise shaping is performed to generate a positive phase digital signal (REF_P) and a negative phase digital signal (REF_N). Both signal patterns are compared at a buffer and pattern comparator section when muting. If the signal patterns match, a selector outputs a set value having 50% duty instead of the digital signals to optimize timing for switching to 50% duty when muting. | 02-12-2009 |
| 20090092264 | AUDIO OUTPUT DEVICE AND METHOD - An audio output device and method capable of preventing generation of pop noise by a relatively simple and small-sized circuit configuration and control timing. A D/A converter converts a digital audio signal to an analog audio signal. A non-inverting amplifier amplifies the analog audio signal. A signal output from the non-inverting amplifier is amplified by inverting amplifiers of two stages with a first timing. A signal output from an inverting amplifier is input to a speaker amplifier by a switch. The output signal of the inverting amplifier is output to a speaker with a second timing subsequent to the first timing. The output signal of the inverting amplifier is amplified by the speaker amplifier and output to the speaker. With a third timing subsequent to the second timing, the output of each of the inverting amplifiers is stopped and the output of the speaker amplifier is stopped. | 04-09-2009 |
| 20090103750 | SUPPRESSING OUTPUT OFFSET IN AN AUDIO DEVICE - A digital offset is combined with an audio signal in the digital domain to cancel an output offset caused by one or more analog components processing the same audio signal. In this manner, the offset at the output of the audio signal path (e.g., at a power amplifier output) is reduced or eliminated. Consequently, audible artifacts, such as click-and-pop artifacts, can be reduced or eliminated. In audio devices operating in ground-referenced capless mode, power consumption is reduced because of reduced or eliminated direct current (DC) leakage current through speakers or headsets of such audio devices. In some circumstances, the digital offset in the digital domain may be applied at substantially all times of operation of the audio signal path. | 04-23-2009 |
| 20090175467 | Audio Output Device and Controlling Method therefor - In an audio output device and controlling method therefor, the audio output device includes a power source, an audio processing unit and a power correction unit. The power source provides power for the audio output device. The audio processing unit processes audio signals. The power correction unit is coupled between the power source and the audio processing unit. The power correction unit corrects the supplied power by slowly charging or discharging for causing a frequency of a pulse audio signal being lower than 20 Hz, wherein the pulse audio signal is correspondingly obtained by the audio processing unit processing a power changing produced by turning on or turning off the power source. | 07-09-2009 |
| 20090196435 | SYSTEM AND METHOD OF REDUCING CLICK AND POP NOISE IN AUDIO PLAYBACK DEVICES - An audio system that reduces or eliminates click and pop noise during power up and power down operations. In particular, the audio system includes an amplifier with an input adapted to receive an input audio signal and an output adapted to produce an amplified output audio signal for an associated speaker. The audio system further includes a noise reduction circuit adapted to smoothly apply and remove a DC voltage to and from the output of the amplifier in a manner that reduces or eliminates click and pop noise from being generated by the associated speaker. The DC voltage at the output of the amplifier may be derived from a DC reference voltage source and/or from the input audio signal. | 08-06-2009 |
| 20090208032 | POP NOISE SUPPRESSION APPARATUS AND AUDIO OUTPUT SYSTEM UTILIZING THE SAME - A pop noise suppression apparatus for eliminating popping noise generated upon initiation or shutdown of an audio output circuit comprises a switch component and a control circuit. The switch component allows the audio output circuit to provide audio through the output of the audio output circuit. The control circuit provides a mute signal for a first period of time in to response initiation or shutdown of the audio circuit. The control circuit comprises a capacitor to be charged upon initiation of the audio output circuit or to be discharged upon shutdown of the audio output circuit. A length of the first period of time during which the mute signal is provided depends on a second period of time to charge or discharge the capacitor. | 08-20-2009 |
| 20090214056 | Sound quality adjustment device - A sound signal switchover means capable of preventing pop noise sound in an audio system from being generated is down-sized, and a time constant of a time constant unit for the changeover of the sound signals can be varied, thereby enabling the switchover to be implemented with greater smoothness. A sound signal selection means ( | 08-27-2009 |
| 20090220106 | AUDIO SIGNAL PROCESSING CIRCUIT - A first amplifier amplifies a first audio signal. A synthesizer circuit synthesizes an output signal of the first amplifier with a second audio signal. The first amplifier is arranged such that a first state in which the first amplifier amplifies a signal with a set gain and a second state in which the first amplifier outputs a fixed bias voltage can be seamlessly switched. A signal processing unit is disposed upstream of the first amplifier, subjects a third audio signal to a predetermined signal process, and outputs it as the first audio signal. When a state of the signal processing unit is switched, the first amplifier is changed from the first state to the second state, the state of the signal processing unit is switched in the second state, and subsequently the first amplifier is switched from the second state to the first state. | 09-03-2009 |
| 20090238379 | APPARATUS AND METHOD FOR MINIMIZING QUANTIZATION NOISE AS MUTING - An apparatus and method for minimizing the quantization noise as muting are provided, and particularly applied to a Delta-Sigma modulator that is used to process digital-to-analog conversion. By means of a zero-sampling detection circuit and a dynamic gain mechanism, a dynamic gain is introduced to minimize the quantization noise occurred as muting. The method preferably includes a first step for receiving the signals by the Delta-Sigma modulator inputted from an audio decoder, and a next step for detecting signal zero by a zero-sampling detection unit and counting the number of the signals with signal zero. The mute state is entered when the number of signal zeros reaches a pre-set number. At the moment, the signaling route is switched to another route with dynamic gain mechanism. Further, the dynamic gain mechanism is activated for producing a dynamic gain, which will be fed back to the input end of the modulator. | 09-24-2009 |
| 20090245534 | POP NOISE ELIMINATING CIRCUIT - An pop noise eliminating circuit includes a power source, a grounding terminal, a speaker, an audio amplifier that has two opposite ends respectively connected with the power source and the first end of the speaker, a delay unit that has one end electrically connected with the power source, a first power control switch that has a control end electrically connected with the delay unit, a first conduction end electrically connected with the other end of the speaker, and a second power control switch that has a control end electrically connected with the delay unit, a first conduction end electrically connected with the grounding terminal, and a second conduction end electrically connected with a second conduction end of the first power control switch. | 10-01-2009 |
| 20090274319 | AUDIO AMPLIFIER - An audio amplifier includes an amplifying circuit, a bias control circuit, and a decoupling device. The amplifying circuit amplifies an audio signal. The bias control circuit provides at least one bias voltage for the amplifying circuit according to a power down signal, in which the power down signal represents that the audio amplifier is powered on or powered down. The decoupling device reduces the damping phenomenon of the bias voltage caused by powering on or powering down the audio amplifier. | 11-05-2009 |
| 20090285411 | AUDIO REPRODUCING APPARATUS - An audio reproducing apparatus includes a power supply, an amplifier, a speaker, and a controller. The power supply is for supplying a voltage. The amplifier is for receiving the voltage and audio signals, amplifying the audio signals, and outputting amplified audio signals. The speaker is for reproducing sound after receiving the amplified audio signals. The controller is for receiving the voltage and generating a control signal to enable the amplifier. The controller includes a generator and a delay unit. The generator is for receiving the voltage and generating the control signal. The delay unit is for delaying the time of transferring the voltage from the power supply to the generator. | 11-19-2009 |
| 20100128898 | METHOD AND APPARATUS FOR OPERATION SEQUENCING OF AUDIO AMPLIFIERS - A circuit, system and method provide the suppression of pop at power up of audio amplifiers. The output driver is tri-stated at power up and is enabled after a predetermined time constant. In one embodiment, the output driver includes a MOS transistor pair connected in a push-pull configuration and switches that are under the control of a delay circuit. the. The output driver and the delay circuit may be part of a power amplifier in an audio system. The delay circuit may be implemented using mixed analog and digital signals or a digital controller configured to receive a clock frequency and execute a machine readable program code. The delay circuit is responsive for the start-up behavior of the audio system. | 05-27-2010 |
| 20100128899 | LARGE RC TIME-CONSTANT GENERATION FOR AUDIO AMPLIFIERS - A circuit for generating a large RC time-constant includes an input node for receiving an input signal making a transition from a first state to a second state characterized by a first time-constant, and an output node for providing an output signal making a transiting from the first state to the second state in response to the input signal. The circuit also includes a first MOS field effect transistor coupled between the input node and the output node. The circuit further includes a first capacitor coupled between the output node and a ground node. A switch circuit is connected to a gate of the first MOS field effect transistor. The switch circuit is configured to bias the MOS field effect transistor to operate in saturation mode and the transition of the output signal is characterized by a time-constant associated with this large output resistance and the capacitor coupled to the output node. | 05-27-2010 |
| 20100158270 | Audio Output Apparatus Capable Of Suppressing Pop Noise - An audio output apparatus includes: an audio codec outputting an analog audio signal corresponding to a digital audio signal from a system controller; a switch unit having a first end coupled to the audio codec through a capacitor, and a grounded second end; and a switch controller triggered by a trigger signal to output a control signal to a control end of the switch unit such that the switch unit couples the capacitor to ground in response to the control signal. The trigger signal is generated by one of the system controller, the audio codec, and a power circuit supplying electric power to the system controller, the audio codec and the switch controller upon occurrence of a condition associated with pop noise, and is outputted to the switch controller before the pop noise is generated, such that the pop noise is conducted to ground via the switch unit. | 06-24-2010 |
| 20100246852 | Output-level-controlling converter device - An output-level-controlling converter device, including a ramp generator, used to generate a ramp signal; and an analog-to-PWM converter, said converter is used to perform conversion digitally for a reference signal by making use of said ramp signal, and output a pulse-width-modulation signal; and a pulse width detector, used to detect a duty cycle of said pulse-width-modulation signal, and output a gain control voltage signal based on said duty cycle, and when said duty cycle is close to 0% or 100%, said ramp generator is used to increase a voltage amplitude of said ramp signal based on a voltage value of said gain control voltage signal, hereby increasing or decreasing said duty cycle of said pulse-width-modulation signal for reducing voltage gain of said reference signal. | 09-30-2010 |
| 20110007912 | DOUBLE INTEGRAL METHOD OF POWERING UP OR DOWN A SPEAKER - An audio subsystem having a waveform generation circuit that generates a power-up signal for controlling an electric signal used to drive a speaker during a power-up period in which the power-up signal has a positive second derivative during a first sub-period of the power-up period and has a negative second derivative during a second sub-period of the power-up period. The first sub-period spans at least one-fourth of the power-up period, and the second sub-period spans at least one-fourth of the power-up period. | 01-13-2011 |
| 20110026735 | Noise reducing circuit - A noise reducing circuit includes a variable low-cut filter disposed at an upstream of a sound signal switching section and has a variable cutoff frequency, and a control circuit which controls the cutoff frequency of the variable low-cut filter to a first cutoff frequency lower than a cutoff frequency of a low-cut filter disposed at downstream of the variable low-cut filter when a switching instruction is not issued from a switching instructing section, and increases the cutoff frequency of the variable low-cut filter to a second cutoff frequency higher than the first cutoff frequency when the switching instruction is issued. The switching of the sound signal switching section is executed after a predetermined period elapses since the switching instruction is issued, and the control section decreases the cutoff frequency of the variable low-cut filter to the first cutoff frequency after the switching of the sound signal switching section is completed. | 02-03-2011 |
| 20110051958 | METHOD FOR REMOVING POP-UP NOISE IN MOBILE DEVICE - A method is provided to remove an unexpected pop-up noise that occurs while audio data such as a key tone is output in an electronic device. The method includes detecting an interruption such as a key release for stopping the output of audio data, and verifying Pulse Code Modulation (PCM) data of the audio data. If there is a gap between an endpoint of the PCM data and a given reference value, the device reduces the gap by revising the endpoint of the PCM data. | 03-03-2011 |
| 20110116652 | SIGNAL OUTPUT DEVICE AND SIGNAL OUTPUT METHOD - A signal output device includes: a control circuit for receiving at least a first input control signal and outputting an output control signal according to at least the first input control signal, wherein the first input control signal comprises a first signal segment followed by a second signal segment; and a driver circuit, operated according to a supply power, for receiving the output control signal from the control circuit and selectively generating an output signal according to the output control signal; wherein the supply power is turned on before the second signal segment of the first input control signal is received by the control circuit; when the supply power is turned on, the driver circuit operates under a specific power state; and when the second signal segment of the first input control signal is received by the control circuit, the driver circuit keeps operating under the specific power state. | 05-19-2011 |
| 20110116653 | PLOP-FREE AMPLIFIER - An amplifier is disclosed, wherein the output stage is split between a primary output stage and a secondary stage. To minimise or eliminate any audible plop when the amplifier is switched on, the primary stage is connected, and the second stage is gradually connected using a switch. The gradual connection can be by means of varying the pulse-density of a pulse wave modulation on the switch, from fully open (0% pulse-density) to fully closed (100%). The inverse process can minimise or eliminate plop during switch-off. Separate feedback loops are switchable, from the primary and secondary stages; in a DC-coupled embodiment, the feedback loop from the secondary stage may include DC-offset cancelling circuitry, to both reduce or eliminate the plop and avoid and DC-offset current through the speaker. | 05-19-2011 |
| 20110158429 | AUDIO APPARATUS - An audio apparatus receives a supply voltage from a power source and is powered on. The audio apparatus includes a control unit, an amplifier, and a mute circuit. The control unit provides an audio signal. The amplifier amplifies the audio signal and drives a speaker to reproduce sound according to the amplified audio signal. The mute circuit generates a mute signal when initially receiving the supply voltage from the power source. The amplifier stops driving the speaker to reproduce sound according to the mute signal. | 06-30-2011 |
| 20110261976 | Signal Amplifying Circuit and Signal Amplifying Method - A signal amplifying circuit is provided. The signal amplifying circuit includes a signal amplifier and a control circuit. The control circuit includes a compare unit and a register unit. The compare unit compares an input signal of the signal amplifier with a reference signal to generate a compare signal. The register unit receives and registers a control signal to be transmitted to the signal amplifier, and provides a registered signal to the signal amplifier according to the registered control signal when the compare signal is changed. | 10-27-2011 |
| 20110293110 | DE-POP CIRCUIT AND AN ASSOCIATED AUDIO SYSTEM - A de-pop circuit adaptable to an audio circuit is disclosed. A high-pass filter generates a high-pass output signal according to an output signal of the audio circuit. A blockage circuit receives the high-pass output signal and a control signal, and generates an enable signal to activate the audio circuit according to the control signal and the high-pass output signal. | 12-01-2011 |
| 20120163628 | METHOD FOR REDUCING DIGITAL AUDIO OUTPUT NOISE - An apparatus for reducing digital audio output noise includes: a signal processing unit configured to process digital audio data to output to a speaker; a switching unit configured to mute the speaker; and a control unit configured to monitor the signal processing unit to determine whether a current state is a mute state or not, and control the switching unit according to the determination result. | 06-28-2012 |
| 20120183155 | CIRCUIT WITH THREE-STAGE OF POWER-ON SEQUENCE USED FOR SUPPRESSING THE POP NOISE IN AUDIO SYSTEM - The present invention discloses a circuit with three-stage of power-on sequence used for suppressing the pop noise in audio system. It mainly comprises a first resistor (R | 07-19-2012 |
| 20120237056 | AUTOMATED NOISE REDUCTION CIRCUIT - An automated noise reduction circuit is configured to find an audio output with the lowest voltage level associated with undesirable noise. The circuit may include a plurality of audio input ports, ground isolation devices, electronic switches and a microprocessor. The microprocessor may be configured to toggle the ground isolation devices on and off, sample voltage at an output of the ground loop isolation transformers when the ground isolation devices are on and off, and switch the ground isolation devices to a position that produces a lowest voltage output based on a comparison of sampled voltage that is analyzed by a set of algorithms programmed into the microprocessor and that has been sampled from the output of the ground isolation devices for each of the multiple input ports. | 09-20-2012 |
| 20120257768 | NOISE REMOVAL METHOD AND SYSTEM - A method and system for removing noise due to bias electric power (MIC_Bias) or Time Division Multiple Access (TDMA) noise are provided. The system includes an interface with a microphone contact, for connecting to an accessory, an Analog-to-Digital (AD) converter for converting an analog voltage level, input via the microphone contact, into a digital voltage level, an audio processing unit for processing an audio signal input via the microphone contact, a switch for at least one of connecting and disconnecting the microphone contact and the AD converter, and a controller. The controller compares the digital voltage level with voltage levels stored in a look up table. The controller identifies a type of accessory connected to the interface. The controller also switches off the switch to prevent noise from being introduced into the audio signal via a wire connecting the microphone contact and the AD converter. | 10-11-2012 |
| 20120281857 | AUDIO AMPLIFIER - An audio amplifier includes a timing control circuit, an amplifying circuit, and a bias control circuit. The timing control circuit generates a first power down signal and a second power down signal, in which the first power down signal is asserted before the second power down signal is asserted. The amplifying circuit receives a bias voltage to amplify an audio signal and is deactivated when the first power down signal is asserted. The bias control circuit provides the bias voltage for the amplifying circuit and is deactivated when the second power down signal is asserted. | 11-08-2012 |
| 20130003988 | POP noise suppressing circuit and its method - A POP noise suppressing circuit includes a blocking capacitor, an outputting element connected to the blocking capacitor, a current generating unit, a charging unit connected to the current generating unit, a discharging unit connected to the current generating unit, a switching unit connected to the charging unit and the discharging unit and a power amplifying unit connected between the switching unit and the blocking capacitor. The current generating unit provides two slowly increasing currents respectively to the charging unit and the discharging unit. The switching unit is for switching between the charging unit and the discharging unit. The charging unit forms a charging current. The discharging unit forms a discharging current. The voltage of the blocking capacitor increases smoothly in a process of powering on and decreases smoothly in a process of powering off. A POP noise suppressing method is also provided. | 01-03-2013 |
| 20130028441 | Pop and Click Noise Reduction - Disclosed are advances in the arts with novel and useful electronic circuitry with pop and click noise reduction. A load circuit is connected with a full or single-ended half-H bridge circuit and another circuit mechanism in a configuration by which a signal may be used to selectably bring the load circuit terminals to a selected voltage level when an externally applied signal is not present. | 01-31-2013 |
| 20130108075 | AUDIO PROCESSING DEVICE AND AUDIO SYSTEMS USING THE SAME | 05-02-2013 |
| 20130223646 | SPEAKER CONTROL METHOD AND SPEAKER CONTROL SYSTEM - A speaker control method includes steps of detecting whether there is any audio signal input; outputting a first voltage signal if there is no audio signal input; outputting a second voltage signal if there is an audio signal input; and selectively turning off an audio amplifier according to the first voltage signal or turning on the audio amplifier according to the second voltage signal, wherein the audio amplifier is used for driving a speaker. | 08-29-2013 |
| 20130236030 | MUTE DRIVE CIRCUIT - A mute drive circuit includes a micro-controller including an I/O port; a mute circuit; and an npn transistor. When an electronic device using the mute circuit is plugged into an AC power source, the I/O port is set to the logic low, the mute circuit performs the mute mode. When the electronic device is turned on, the I/O port is controlled set to the logic low for a period and then be pulled up to the logic high, the mute circuit performs the mute mode for the period and then enters into the normal mode. When the electronic device is turned off, the I/O port is controlled to set to the logic low, the mute circuit performs the mute mode. When the electronic device is unplugged from the AC power source, the I/O port is pulled down to the logic low, the mute circuit performs the mute mode. | 09-12-2013 |
| 20130266153 | ANTI-POP CIRCUIT - An exemplary anti-pop circuit for use in an electronic device includes a switch module, a first path module, and a second control module. The first path module outputs a first response signal when the electronic device is being started, the switch module cuts off the connection between the audio IC and the speaker in response to the first response signal. The second control module includes a charge/discharge unit and a second path module. The charge/discharge unit is charged by the DC power supply when the electronic device is being started, and discharges to the second path module when the electronic device is being shut down. The second path module outputs a second response signal when the electronic device is being shut down, the switch module cuts off a connection between the audio IC and the speaker in response to the second response signal. | 10-10-2013 |
| 20130308791 | APPARATUS AND METHOD FOR REDUCING AUDIBLE NOISE OF POWER SUPPLY - A method for reducing audible noise of a power supply provides a PWM signal for controlling a power converter. First, a feedback voltage is produced by detecting an output voltage of the power converter. Afterward, a burst-in voltage and a burst-out voltage are set. Afterward, a voltage level of the burst-in voltage or a voltage level of the burst-out voltage is dynamically varied. Afterward, the PWM signal is switched off when the feedback voltage is less than the burst-in voltage. Final, the PWM signal is switched on when the feedback voltage is greater than the burst-out voltage. | 11-21-2013 |
| 20130322650 | NOISE ELIMINATION CIRCUIT FOR AUDIO EQUIPMENT - A noise elimination circuit of a computer includes a switch and a converting chip. The switch includes first, second, and third electrodes. The first electrode is connected to a control terminal and the third electrode is connected to a first voltage source. The converting chip includes an input pin and an output pin. The input pin is connected to a second voltage source. The output pin is connected to a control chip that controls a speaker. The output pin is connected to the second electrode. The second voltage source powers on the input pin when the computer is triggered to be powered on and powers off the input pin when the computer is triggered to be powered off. The control terminal sends a control signal to the first electrode to actuate the switch, after the computer is triggered and before the second voltage source powers on the input pin. | 12-05-2013 |
| 20130336501 | ELECTRONIC DEVICE FOR SUPPRESSING NOISE - An electronic device capable of audio files with different formats includes a power supply, a switching circuit, an audio control module, an audio output module, and a detecting module. The power supply supplies a first voltage and a second voltage. The detecting module detects whether the format of the audio file is changed. The detecting module generates a first detecting signal within a first predetermined time period from a point in time when the format of the audio file is changed time point, and the switching circuit transmits the first voltage to the audio control module in response to the first detecting signal. The audio control module receives the second voltage and generates a first signal based on the first voltage and the second voltage. The audio output module is disabled from outputting audio signal of the audio file. | 12-19-2013 |
| 20140003621 | GROUNDING SWITCH METHOD AND APPARATUS | 01-02-2014 |
| 20140072143 | AUTOMATIC MICROPHONE MUTING OF UNDESIRED NOISES - Methods and systems for cancelation of table noise in a speaker system used for video or audio conferencing are disclosed. Table noise is cancelled in one embodiment by providing a signal or a message whenever a key is depressed on a keyboard or a mouse is clicked. When the key depression signal or message is received, the system evaluates whether speech is occurring. If speech is not occurring, then the microphone in the system is muted. However, if speech is occurring, the microphone is not muted for a period of time to allow the speech to be transmitted to the far end. This allows the conference to be continued in the presence of keyboard sounds if speech is occurring at the same time but also silences the keyboard sounds if speech is not occurring. | 03-13-2014 |
| 20140086432 | POP noise suppression circuit and system - A POP noise suppression circuit includes a power source terminal, a clock signal input terminal, a charge unit, a discharge unit, a common-mode voltage judging and switching control unit, a charge and discharge capacitor, and a ground terminal. The charge unit includes a first clock generation circuit for generating a first pair of non-overlapped clock signal, and a first equivalent resistor. The discharge unit includes a second clock generation circuit for generating a second pair of non overlapped clock signals, and a second equivalent resistor. The charge unit generates a charge voltage changing slowly to the charge and discharge capacitor. The discharge unit generates a discharge voltage changing slowly to the charge and discharge capacitor. A POP noise suppression system is further provided. | 03-27-2014 |
| 20140098974 | Pop/Click Noise Reduction Circuitry For Power-Up And Power-Down of Audio Output Circuitry - Pop/clock noise reduction circuitry is disclosed for audio output circuitry. After audio output circuitry is enabled, reference voltage generator circuitry is then enabled to produce a reference voltage that ramps from a first voltage level to a second voltage level at a smooth rate. The ramping reference voltage is applied to the input of the audio output circuitry to reduce or prevent pop/click noise for the audio output circuitry. Further, negative offset control circuitry can also be used to provide a negative offset input to the audio output circuitry to remove initial step-up voltage levels that may exist at operational power-up for the audio output circuitry. Still further, current control circuitry can also be used that limits the available current flowing to the output node for the audio output circuitry, thereby further reducing and/or preventing potential pop/click noise in the audio output signals. | 04-10-2014 |
| 20140270251 | SHARING A DESIGNATED AUDIO SIGNAL - A system and method for sharing a designated audio signal may reproduce the designated audio signal via transducer into an acoustic space. The designated audio signal may be a recorded audio signal, an encoded audio signal, a streamed audio signal and an audio signal component of a multi-media content item. An input audio signal may be received representing a sound field in the acoustic space. One or more microphones may receive the input audio signal. A component contributed by the reproduced designated audio signal may be suppressed in the input audio signal. An echo suppressor may suppress the recaptured designated audio signal. The designated audio signal may be mixed with the suppressed input audio signal to generate an uplink audio signal. The designated audio signal mixed with the suppressed input audio signal may not include artifacts caused by the transducer, the microphone and the acoustic space. | 09-18-2014 |
| 20140270252 | Signal Artifact Detection and Elimination for Audio Output - A method and apparatus are provided for processing a received digital radio broadcast signal to efficiently remove signal interference artifacts from digital and/or analog signals by using signal quality information extracted from audio samples in one or more buffered audio frames to detect audio frames containing clipped noise artifacts and weaker noise artifacts and to selectively apply anti-interference processing to remove the signal interference artifacts. | 09-18-2014 |
| 20140348343 | AUDIO DEVICE FOR SUPPRESSING NOISE - An audio device is capable of switching between a first state and a second state. The audio device comprises a power supply, a delay module, a control module, a processor, and an audio-playing module. The power supply provides a working voltage when the audio device is in the second state. The delay module is connected between the power supply and the control module, and outputs a delay signal when the audio device switches between the first state and the second state. The control module for outputting a driving signal is prevented from outputting driving signal in response to the delay signal, and the processor is enabled in response to the delay signal. | 11-27-2014 |
| 20140369520 | Negative Audio Signal Voltage Protection Circuit and Method for Audio Ground Circuits - Self-grounded circuitry ( | 12-18-2014 |
| 20150016630 | POP-CLICK NOISE GROUNDING SWITCH DESIGN WITH DEEP SUB-MICRON CMOS TECHNOLOGY - A device for grounding pop-click noise may include an output block configured to generate an output signal at an output node. A switch circuit coupled to the output node may be configured to be operable to couple the output node to a ground potential. The switch circuit may include a first and a second transistor. A drain, a source, and a gate node of the first transistor may be coupled to the output node, a drain node of the second transistor, and a first control signal, respectively. A drain, a source, and a gate node of the second transistor may be coupled to a source node of the first transistor, the ground potential, and a second control signal, respectively. The first and the second control signals may operate the switch circuit to couple the output node to the ground potential during a pre-determined period associated with the pop-click noise. | 01-15-2015 |
| 20150063593 | Noise and Cross-Talk Attenuation in an Audio System by Offsetting Outputs in Phase - An amplifier may include two or more pulse-width modulators (PWMs) controlling respective sets of switches to produce an amplified version of a source signal. The clocking for the amplifier may be controlled to delay signal processing within the PWMs relative to one another in time, thereby providing an effective time offset between the absolute moment in time of the edge transition of the controlling signals to the respective sets of switches. The PWMs may include a decrementor that counts down to zero from the next PWM duty-cycle value when a new data sample is detected, beginning a new count when the next sample is present. The PWM output may correspond to the counter value, outputting a pulse when the counter value is nonzero. A “data-sample-ready” signal may be decoded from a master counter, which may be clocked based on the high speed PWM clock, and the delay mechanism may be based on adjusting the decode value to determine when the PWM should initialize to the next data sample. | 03-05-2015 |
| 20150071463 | METHOD AND APPARATUS FOR FILTERING AN AUDIO SIGNAL - It is inter alia disclosed to determine a peak energy level for an audio frame of a band limited audio signal; determine that the peak energy level is a maximum peak energy level by determining that the peak energy level exceeds a peak energy level determined for at least one neighboring audio frame by a first predetermined energy threshold value; classify a region of audio samples associated with the maximum peak energy level as an audio click; and suppress audio samples of the region of audio samples classified as an audio click by multiplying at least one audio sample of the audio frame with a sample wise suppressor gain function. | 03-12-2015 |
| 20150071464 | METHODS AND CIRCUITS TO REDUCE POP NOISE IN AN AUDIO DEVICE - A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change. | 03-12-2015 |
| 20150131811 | SIGNAL OUTPUT DEVICE AND SIGNAL OUTPUT METHOD - A signal output device includes: a control circuit for receiving at least a first input control signal and outputting an output control signal according to at least the first input control signal, wherein the first input control signal has a first signal segment followed by a second signal segment, and a voltage level of the first signal segment is unknown; and a driver circuit, operated according to a supply power, for receiving the output control signal from the control circuit; wherein a voltage of the supply power is settle before the second signal segment of the first input control signal is received by the control circuit; when the supply power is turned on, the driver circuit operates under a specific power state; and when the second signal segment of the first input control signal is received by the control circuit, the driver circuit keeps operating under the specific power state. | 05-14-2015 |
| 20150146884 | CIRCUIT FOR SUPPRESSING AUDIO OUTPUT NOISE AND AUDIO OUTPUT CIRCUIT - A circuit for suppressing audio output noise and an audio output circuit are provided. The circuit for suppressing audio output noise includes: a detecting circuit, configured to detect output voltages of output stages of an audio power amplifier; a control circuit, configured to output at least one control signal, the control signal is related to detection results of the detecting circuit; and a compensating circuit, configured to compensate at least one output stage of the audio power amplifier which includes a differential circuit based on the at least one control signal output by the control circuit, to make parameters of the differential circuit symmetrical or approach symmetrical. Based on detection results of the output stage voltages, the differential circuit in the output stages of the audio power amplifier is compensated. The circuit for suppressing audio output noise has a wider application scope and it is easy to design the circuit. | 05-28-2015 |
| 20160056786 | MICROPHONE BIASING CIRCUITRY AND METHOD THEREOF - A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path. | 02-25-2016 |
| 20160099698 | METHOD AND APPARATUS FOR REDUCING NOISE DUE TO PATH CHANGE OF AUDIO SIGNAL - A method and an apparatus for reducing noise due to a path change of an audio signal output from a device are provided. The method includes determining an input period for canceling the noise by using a time point, at which the path change is sensed, as a reference, when sensing the path change of the audio signal; low-pass filtering the audio signal in the determined input period; and interpolating a first partial signal, which is the low-pass filtered audio signal in a first predetermined period that starts from a start time point of the determined input period, and a second partial signal, which is the low-pass filtered audio signal in a second predetermined period that ends at an end time point of the determined input period, within the determined input period. | 04-07-2016 |
| 20160142804 | MICROPHONE - Provided is, in a microphone configured such that a microphone head including a microphone unit is attachably/detachably mounted to a microphone main body, a microphone which enables easy attachment/detachment of the microphone head, and which can perform a mute operation not only after removal of the microphone head but also in attachment/detachment of the microphone head. The microphone includes a mute circuit provided to a side of the microphone main body, and driven by an input of a mute command signal, a first mute control circuit provided to aside of the microphone head, and including a switch that switches disconnection/conduction of a wire, and a second mute control circuit provided to the side of the microphone main body, and electrically connected with the first mute control circuit and generates the mute command signal, in a state where the microphone head is coupled, and in attachment/detachment of the microphone head. | 05-19-2016 |
| 20160203811 | System and Method for Transitioning Between Audio System Modes | 07-14-2016 |
