With Amplitude Compression/expansion Patents (Class 381/106)
  • Patent number: 7630507
    Abstract: A multi-channel signal processing system adapted to provide binaural compressing of tonal inputs is provided. Such a system can be used, for example, in a binaural hearing aid system to provide the dynamic-range binaural compression of the tonal inputs. The multi-channel signal processing system is essentially a system with two signal channels connected by a control link between the two signal channels, thereby allowing the binaural hearing aid system to model behaviors, such as crossed olivocochlear bundle (COCB) effects, of the human auditory system that includes a neural link between the left and right ears. The multi-channel signal processing system comprises first and second channel compressing units respectively located in first and second signal channels of the multi-channel signal processing system. The first and second channel compressing units receive first and second channel input signals, respectively, to generate first and second channel compressed outputs.
    Type: Grant
    Filed: January 27, 2003
    Date of Patent: December 8, 2009
    Assignee: GN Resound A/S
    Inventor: James M. Kates
  • Patent number: 7624259
    Abstract: A system and method for improved audio controls on a personal computer is provided. The system and method provide a unified architecture for audio controls across hardware and software interfaces of the personal computer. An intelligent facility may automatically change audio controls for users to simply interact with various communications and media applications. To this end, a configurable audio controller intelligently handles various aspects of the system's audio devices by following various rules that may be based at least in part on user-configurable settings and a current operating state. The present invention also provides audio controls so that a user may easily change audio settings such as the volume of an audio output device. There are many applications that may use the present invention for automatic control of audio devices based upon the user's context.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: November 24, 2009
    Assignee: Microsoft Corporation
    Inventors: Eric Gould Bear, Chad Magendanz, Aditha May Adams, Carl Ledbetter, Steve Kaneko, Dale C. Crosier
  • Patent number: 7620544
    Abstract: A method and apparatus for detecting speech segments of a speech signal processing device is provided. A critical band is divided into a certain number of regions according to noise frequency characteristics, a signal threshold and a noise threshold are set for each of the regions, and it is determined whether each frame is a speech segment or noise segment by comparing the log energy calculated for each region to the corresponding signal threshold and noise threshold. Therefore, a speech segment can be detected rapidly and accurately by using a small number of operations even in a noise environment.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: November 17, 2009
    Assignee: LG Electronics Inc.
    Inventor: Kyoung-Ho Woo
  • Patent number: 7617109
    Abstract: A coded signal conveys encoded audio information and metadata that may be used to control the loudness and dynamic range of the audio information during its playback. If the values for these metadata parameters are set incorrectly, annoying fluctuations in loudness during playback can result. The present invention overcomes this problem by detecting incorrect metadata parameter values in the signal and replacing the incorrect values with corrected values.
    Type: Grant
    Filed: July 1, 2004
    Date of Patent: November 10, 2009
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Michael John Smithers, Jeffrey Charles Riedmiller, Charles Quito Robinson, Brett Graham Crockett
  • Patent number: 7609840
    Abstract: A control system and associated method resolving audio conflicts. The control system comprises a computing device, a memory device comprising a database, and a plurality of audio sources. The memory device is coupled to the computing device. The database comprises input data. The computing device is adapted to control an audio level for each of said audio sources in response to said input data to resolve audio conflicts between the audio sources.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: October 27, 2009
    Assignee: International Business Machines Corporation
    Inventors: Gregory J. Boss, Carl P. Gusler, Rick A. Hamilton, II, James W. Seaman
  • Patent number: 7599503
    Abstract: In a device equipped with an audio output, a range of the audio output level in regular use is set. When an attempt is made to change the setting to a volume level exceeding the range of the audio output level having been set, a request is made for an acknowledgement that the operation is appropriate, and only if a reply is received within a given time, is the volume setting changed. Such a method prevents the audio output from a television set or audio equipment to be increased to a volume level higher than necessary due to an operating error in a volume setting operation.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: October 6, 2009
    Assignee: Panasonic Corporation
    Inventor: Tomohiko Taniguchi
  • Patent number: 7599504
    Abstract: An apparatus for adjusting sound volume for an audio system includes a controller (101) connected to an amplifier (40) of the audio system, an audio processor (104), a circuit (102) for adjusting sound volume, and a communication port (103). The controller controls the amplification of the amplifier through the communication port. The circuit includes an adjustor (1022) connected to the audio processor, and a switch (1024) coupled to the audio processor. The controller controls the switch to switch an operating mode of the circuit between a normal mode and an attenuation mode. The adjustor is coupled to the switch. In the normal mode, the switch directly transmits unadjusted audio signals to the audio processor. In the attenuation mode, the audio processor controls the adjustor to output unadjusted audio signals or attenuated audio signals. A related method for adjusting sound volume for an audio system is also disclosed.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: October 6, 2009
    Assignee: Hon Hai Precision Industry Co., Ltd.
    Inventor: Kuan-Hong Hsieh
  • Patent number: 7596232
    Abstract: An apparatus (10) for adjusting sound volume for an audio system includes a controller (101) connected to an amplifier (40) of the audio system for controlling amplification of the amplifier, and a first circuit (102) for adjusting the sound volume. The controller includes a microprogrammed control unit (1010), a random-access memory (1012), and an electrically erasable programmable read-only memory (1014). The first circuit includes an attenuation circuit (1022) connected to a tuner (20) of the audio system for attenuating input audio signals, and a switch (1024). An input end of the switch is connected to the tuner, an output end of the attenuation circuit and the microprogrammed control unit; and an output end of the switch is connected to an audio processor (30). The apparatus enables a user to freely adjust an average level of sound produced by the audio system, and simultaneously avoid being bothered by loud transmissions.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: September 29, 2009
    Assignee: Hon Hai Precision Industry Co., Ltd.
    Inventor: Kuan-Hong Hsieh
  • Patent number: 7590251
    Abstract: Systems and methods for detecting clipping conditions in an audio signal and processing the signal to reduce the clipping conditions. In one embodiment, a system comprises a noise shaper, a modulator, an output stage and other components. A detector detects clipping in the noise shaper and a signal processor processes the audio signal input to the noise shaper based on feedback received from the detector. The signal processor may function to modify the input audio signal in different ways in response to different conditions that are detected by the detector. A filter may be included to filter the output of the detector before being provided to the signal processor. A flag circuit may be coupled between the filter and the signal processor to assert an output signal until the signal processor resets the flag circuit.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: September 15, 2009
    Assignee: D2Audio Corporation
    Inventors: Jack B. Andersen, Larry E. Hand, Wilson E. Taylor
  • Patent number: 7580531
    Abstract: An audio amplifier is provided having a compressor with an automatically-adjustable compressor. Compression is linked to the volume control in an inverse relationship whereby, when the volume is reduced, the compression ratio is increased to boost the listening level of quieter passages in the source material. Conversely, when the volume is increased, the compression ratio is decreased. The compression control may be physically connected to the volume control, such as in a dual-potentiometer, or may be coupled electronically, such as with a digital signal processor. An effects level control may be included to allow a listener to increase or decrease the effect of the compression by applying a multiplier to the compression ratio. An ambient noise detector may also be included such that compression is increased as ambient noise increases or exceeds a predetermined level.
    Type: Grant
    Filed: February 6, 2004
    Date of Patent: August 25, 2009
    Assignee: Cirrus Logic, Inc
    Inventor: Charles Anderson
  • Patent number: 7558391
    Abstract: Compander architecture and method for ensuring that the components of an output signal are synchronized includes calculating a gain calculation for an input signal, detecting a predetermined condition such as a zero crossing or absence of a zero crossing within a specified period, and ensuring that the result of the gain calculation is providing to the system synchronously with the input signal. The input signal may be divided into one or more signals for processing, and the gain calculation may include one or more power estimations and one or more gain cells associated with the multiple signals, and may further include variable attack and release.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: July 7, 2009
    Inventor: Karl L. Bizjak
  • Patent number: 7557289
    Abstract: A music delivering apparatus includes a storing unit that stores musical data, a sound collecting unit that collects a voice from outside to output audio data, a reading unit that reads the musical data from the storing unit, a mixer that mixes the audio data with the musical data read out by the reading unit to output sound data, a transmitting unit that transmits the sound data to a client, and a volume control unit that lowers volume of the musical data that is read out by the reading unit and supplied to the mixer while the audio data is supplied to the mixer.
    Type: Grant
    Filed: November 30, 2005
    Date of Patent: July 7, 2009
    Assignee: Yamaha Corporation
    Inventor: Katsuaki Tanaka
  • Patent number: 7551745
    Abstract: A single control determines both volume and the degree of compression in the reproduction of motion picture soundtracks. For some settings of the control, compression or limiting reduces the highest levels on a movie soundtrack, leaving the dialogue level substantially unchanged, thus removing the reason for complaints from the audience without the danger of making the dialogue too quiet for intelligibility.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: June 23, 2009
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Kenneth James Gundry, John Iles, Roger Wallace Dressler
  • Patent number: 7532728
    Abstract: An BTSC encoder with an improved digital filter structure substantially implemented on a single CMOS integrated circuit is described. By cascading first and second order allpass filter structures to form a higher order digital filter, such as a Cauer low pass filter, limit cycle oscillations are reduced or eliminated, word-length growth from one stage to the next is contained, and a more efficient overall filter structure and performance is obtained.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: May 12, 2009
    Assignee: Broadcom Corporation
    Inventors: Gopal Venkatesan, Amy Hundhausen, Hosahalli Srinivas, Erik Berg
  • Publication number: 20090116665
    Abstract: An audio signal in which an audio signal is received as a stream of digital samples, each being a numerical value representing a sampled signal level. A first zero crossing point is identified and the received audio samples are stored until a second zero crossing point is identified, thereby storing a first half-wave of samples. The highest intensity sample is identified from the stored samples and this is compared against a predetermined threshold. All stored samples are scaled by an initial scaling factor so that the intensity of the highest intensity sample is not above this threshold. A second half-wave of samples is stored in which all samples of the second half-wave are below the threshold. All stored samples of the second half-wave are also scaled but by a modified scaling factor derived from a combination of the initial scaling factor and a decay factor.
    Type: Application
    Filed: November 4, 2008
    Publication date: May 7, 2009
    Applicant: RED LION 49 LIMITED
    Inventor: Craig Nicholas Grove
  • Publication number: 20090116664
    Abstract: The level of an audio signal can be compressed by receiving an input audio signal, determining a measure of loudness of the signal using a perceptually derived filter, determining a target gain amount, determining a current gain amount using piecewise linear attack/release logic, and producing an output audio signal by adjusting the input audio signal by the current gain amount. An audio compression filter for compressing the level of audio can comprise a loudness measuring module configured to determine a measure of loudness using a perceptually derived filter, and a compression module configured to determine a target gain amount, determine a current gain amount using piecewise linear attack/release logic, and adjust an input audio signal by the current gain amount. Audio level compression can be implemented using integer calculations.
    Type: Application
    Filed: November 6, 2007
    Publication date: May 7, 2009
    Applicant: Microsoft Corporation
    Inventors: Serge Smirnov, James D. Johnston, Chris Messer
  • Publication number: 20090110214
    Abstract: A circuit to supply power to a load incorporates a first power source, a second power source that may be detachable, a power converter and at least one capacitor (capacitive element), where the first power source is capable of powering the load when charged, where the second power source is not capable of powering the load, but the second power source is capable of trickle-charging the first power source at a time when the first power source is not powering the load, where the power converter may impose a limit on a flow of current through the power converter, and where the at least one capacitor may cooperate to temporarily support a flow of additional current that circumvents the power converter at a time when the load attempts to draw a relatively greater amount of current.
    Type: Application
    Filed: October 30, 2007
    Publication date: April 30, 2009
    Inventors: Roman N. Litovsky, Hal P. Greenberger
  • Patent number: 7519189
    Abstract: In accordance with the invention, audio signals are specially processed for sound presentation in a high noise environment. The electrical signal representative of the sound is first subjected to equalization to preferentially reduce the magnitude of bass signals while increasing the magnitude of treble signals. The equalized signal is then compressed, and the compressed signal is subjected to “mirror image” equalization which increases the magnitude of bass signals while reducing the magnitude of treble signals. The resulting signal fed to the speakers provides a sound presentation of compressed volume range and a bass-rich sound spectrum. It is particularly useful for providing quality sound presentation in a high noise environment.
    Type: Grant
    Filed: June 18, 2007
    Date of Patent: April 14, 2009
    Inventor: Anthony Bongiovi
  • Publication number: 20090086996
    Abstract: The present invention provides for methods and systems for digitally processing an audio signal. Specifically, the present invention provides for a speaker system that is configured to digitally process an audio signal in a manner such that studio-quality sound that can be reproduced.
    Type: Application
    Filed: December 11, 2008
    Publication date: April 2, 2009
    Inventors: Anthony Bongiovi, Phillip Fuller
  • Patent number: 7489790
    Abstract: Systems, devices, and methods are provided to inhibit apparent amplitude modulation in non-linear processing that causes distortion in a processed signal. One aspect of the invention includes a hearing aid. The hearing aid includes a microphone to receive an input signal, a speaker to reproduce the input signal, and a processor. The processor processes the input signal using a gain. The processor includes an inhibitor, which inhibits distortions, and an adjuster, which adjusts the gain. The inhibitor acts to smooth an envelope of the input signal to inhibit undesired modulation. The adjuster adjusts the gain if the envelope is either above or below a threshold.
    Type: Grant
    Filed: December 5, 2000
    Date of Patent: February 10, 2009
    Assignee: AMI Semiconductor, Inc.
    Inventors: Jon Schmidt Kindred, Bryant Sorensen, Jerry Wahl
  • Publication number: 20080310652
    Abstract: Audio compressor device (20) for processing an audio signal and controlling a signal amplifier (24), comprising a signal analyser function (27,29) devised to analyse an input signal during a time frame (28) to determine if the signal represents noise or audio data, wherein the audio compressor device is adapted to set a gain for the signal amplifier dependent on the analysis. The analyser function may comprise an auto-correlation function (27), operative to perform auto-correlation of the input signal in a process for determining if the signal represents noise or audio data.
    Type: Application
    Filed: May 30, 2006
    Publication date: December 18, 2008
    Applicant: SONY ERICSSON MOBILE COMMUNICATIONS AB
    Inventor: Stefan Gustavsson
  • Patent number: 7460674
    Abstract: An audio effector circuit includes a first automatic level control circuit for processing an input audio signal into a first control-resultant audio signal, and a second automatic level control circuit for processing the input audio signal into a second control-resultant audio signal. The first automatic level control circuit has a first predetermined attack time and a first predetermined release time longer than the first predetermined attack time. The second automatic level control circuit has a second predetermined attack time and a second predetermined release time. The second predetermined attack time is longer than the first predetermined attack time. The second predetermined release time is substantially equal to the first predetermined release time. A subtracter operates for providing a difference signal representing a difference between the first control-resultant signal and the second control-resultant signal. An adder operates for adding the difference signal to the input audio signal.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: December 2, 2008
    Assignee: Victor Company of Japan, Ltd.
    Inventor: Hiroaki Sato
  • Patent number: 7457424
    Abstract: An electronic volume device of an invention includes a common volume I/O 371 for receiving an i-th common volume level Dcom[i] (i=1 to N) on a common scale of N steps, a volume converter 373 for converting the Dcom[i] into a j-th unique volume level Dvol[j] on a unique scale of n steps; and a volume controller 372 for controlling an electronic volume based on the unique volume. The volume converter 373 includes a volume memory for storing an offset between the Dcom[i] and the Dvol [j] and a volume controller that controls at least one of the Dvol[j] and the offset such that the received Dcom agrees with the sum of the Dvol[j] and the offset and controls the Dvol[j] on a higher priority than the offset.
    Type: Grant
    Filed: September 15, 2003
    Date of Patent: November 25, 2008
    Assignees: Honda Giken Kogyo Kabushiki Kaishi, Honda Access Corp.
    Inventors: Mutsumi Katayama, Masashi Hino
  • Patent number: 7457422
    Abstract: A method and implementation for detecting and characterizing audible transients in noise includes placing a microphone in a desired location, producing a microphone signal wherein the microphone signal is indicative of the acoustic environment, processing the microphone signal to estimate the acoustic activity that takes place in the human auditory system in response to the acoustic environment, producing an excitation signal indicative of the estimated acoustic activity, processing the excitation signal to identify each impulsive sound frequency-dependent activity as a function of time, producing a detection signal indicative of audible impulse sounds, processing the detection signal to identify an audible impulsive sound, and characterizing each impulsive sound.
    Type: Grant
    Filed: November 29, 2001
    Date of Patent: November 25, 2008
    Assignee: Ford Global Technologies, LLC
    Inventors: Jeffry Allen Greenberg, Michael Alan Blommer, Scott Andrew Amman
  • Patent number: 7440577
    Abstract: Methods and apparatus for automatically mixing a plurality of audio channels by adjusting respective gains of the audio channels using a control signal based on an aggregate of input levels of respective audio signals of the audio channels; and reducing the gain of a given one of the audio channels when an input level of the audio signal of that audio channel exceeds a threshold, irrespective of whether the control signal would permit the gain to rise higher.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: October 21, 2008
    Assignee: Peavey Electronics Corporation
    Inventor: Elon Ray Coats
  • Patent number: 7430296
    Abstract: An audio system includes a first transformation device provided with an input audio signal and which transforms the input audio signal from the time domain to the frequency domain resulting in an input spectrum. The system also includes a spectral processing device, which is connected downstream from the first transformation device, that receives the input spectrum and produces from it an output spectrum with a dynamic range that is reduced from that of the input spectrum. The system further includes a second transformation device connected downstream from the spectral processing device, and provided with the output spectrum. The second transformation device transforms the output spectrum from the frequency domain to the time domain, and provides an output audio signal.
    Type: Grant
    Filed: July 9, 2003
    Date of Patent: September 30, 2008
    Assignee: Harman Becker Automotive Systems GmbH
    Inventors: Georg Spielbauer, Markus Christoph
  • Publication number: 20080212799
    Abstract: An audio compressor may regulate the level of an audio input signal depending on whether the level is above or below a threshold value. The audio compressor may control a pumping that is created when regulating a dynamic range of an audio signal with the threshold value. A feedback loop connecting the signal output from the audio compressor with a release filter may be used to modify an effective release time of the signal. A controller may be used that allows a filter coefficient of the release filter to be controlled to adjust the effective release time as a function of the signal output.
    Type: Application
    Filed: November 15, 2007
    Publication date: September 4, 2008
    Inventor: Hannes Breitschadel
  • Patent number: 7415119
    Abstract: A control system and associated method resolving audio conflicts. The control system comprises a computing device, a memory device comprising a database, and a plurality of audio sources. The memory device is coupled to the computing device. The database comprises input data. The computing device is adapted to control an audio level for each of said audio sources in response to said input data to resolve audio conflicts between the audio sources.
    Type: Grant
    Filed: August 24, 2004
    Date of Patent: August 19, 2008
    Assignee: International Business Machines Corporation
    Inventors: Gregory J Boss, Carl P. Gusler, Rick A. Hamilton, II, James W. Seaman
  • Patent number: 7403627
    Abstract: A method for audio downmix apparatus with dynamic-range control includes steps as follows. The procedure first calculates the power of a surround audio channel and a central audio channel and then estimates whether a gain of the surround audio channel and the central audio channel saturate or not. When the gain is saturated, the procedure enters a step for adjusting a gain of dynamic range control; while the gain is not saturated, the procedure enters a saturation process. After the step of adjusting a gain of dynamic range control, then processes a gain calculation; and then changes the gain and estimates whether the gain reaches a default value or not. When the gain reaches the default value, then the gain will be outputted. When the gain does not reach the default value, continues to process the gain calculation and change the gain.
    Type: Grant
    Filed: January 22, 2004
    Date of Patent: July 22, 2008
    Assignee: Ali Corporation
    Inventor: Gin-Der Wu
  • Patent number: 7403626
    Abstract: Arrangements are made such that a plurality of operators, such as faders, can be set to opposite operational directions. When any one of the operators has been operated in a particular direction, a control value of each of the other operator, set to the same operational direction as the operated operator, is controlled in the same direction as the particular operated direction, while a control value of each of the other operators, set to the opposite operational direction from the operated operator, is controlled in the opposite direction from the particular operated direction. Where control values of a plurality of channels are to be controlled via a collective control controller, each of the channels is set to a forward or inverse operational direction. Thus, even faders that are to be operated in opposite directions can be appropriately operated collectively as a group.
    Type: Grant
    Filed: July 9, 2003
    Date of Patent: July 22, 2008
    Assignee: Yamaha Corporation
    Inventors: Masaru Aiso, Akio Suyama
  • Patent number: 7391875
    Abstract: A method for processing audio signal that includes receiving a plurality of digital audio signals and calculating signal levels of them. The next step is calculating smooth attenuation signal for each one of the input audio signals. The smooth attenuation signals are calculated according to the signal levels and smoothing criteria, such that the mixing of signals that include the input audio signals multiplied by their respective smooth attenuation signals is peak limited by a given threshold level.
    Type: Grant
    Filed: June 21, 2004
    Date of Patent: June 24, 2008
    Assignee: Waves Audio Ltd.
    Inventor: Meir Shashoua
  • Patent number: 7388959
    Abstract: A Harmonic Generator for audio applications and a Pre-Amplifier circuit are combined to form a Harmonic Generator and Pre-Amplifier circuit. The Harmonic Generator is formed from a Buffer Circuit responsive to an input program signal for buffering the input program signal and for providing a buffered input program signal. A Modulator Circuit is coupled to receive the buffered input program signal and generates harmonics in response to changes in amplitude of the program input signal to provide a modulated input program signal. A Summing Circuit adds the buffered input program signal and the modulated input program signal to provide a composite modulated input program signal. The Pre-Amplifier is coupled to receive the composite modulated input programing signal and process the signal in three audio frequency bands to provide a compensated output signal that includes harmonics generated by the modulator.
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: June 17, 2008
    Assignee: BBE Sound, Inc.
    Inventor: Paul R. Gagon
  • Publication number: 20080123873
    Abstract: A digital audio system including a combination of analog and digital volume control is disclosed. A variable power supply voltage biases a power amplifier for each channel, and applies a bias voltage corresponding to an analog volume control signal. In one disclosed embodiment, digital gain control circuitry compares the bias voltage with the level expected for the analog volume control signal; if the bias voltage has not dropped in response to a reduction in the analog volume control signal, the digital gain control circuitry reduces the digital gain of the input digital audio signal, until the bias voltage responds to the reduced volume. In another disclosed embodiment, modeling or characterization of the audio system is used to derive a digital gain control signal based on the desired volume signal and the amplitude of the digital audio signal itself.
    Type: Application
    Filed: November 29, 2006
    Publication date: May 29, 2008
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Anker Bjorn-Josefsen, David E. Zaucha, Thomas Morch
  • Publication number: 20080112576
    Abstract: In accordance with the invention, audio signals are specially processed for sound presentation in a high noise environment. The electrical signal representative of the sound is first subjected to equalization to preferentially reduce the magnitude of bass signals while increasing the magnitude of treble signals. The equalized signal is then compressed, and the compressed signal is subjected to “mirror image” equalization which increases the magnitude of bass signals while reducing the magnitude of treble signals. The resulting signal fed to the speakers provides a sound presentation of compressed volume range and a bass-rich sound spectrum. It is particularly useful for providing quality sound presentation in a high noise environment.
    Type: Application
    Filed: June 18, 2007
    Publication date: May 15, 2008
    Inventor: Anthony Bongiovi
  • Patent number: 7362872
    Abstract: A compander for noise reduction of a FM signal is described, wherein a group delay (?) linked to the generation of the compressor gain (cc(t)) is equalised during generation of the multiplex signal (m(t)), and a group delay (?) linked to the generation of the expander gain (ce(t)) is equalised during generation of the sum signal (us(t)) and the expanded difference signal (ue(t)). Alternatively or additionally the compressor gain and/or the expander gain is controlled by an auxiliary signal on the basis of a combination of sum signal and difference signal of the FM signal. Such companders avoid overmodulation in the transmitter.
    Type: Grant
    Filed: August 22, 2002
    Date of Patent: April 22, 2008
    Assignee: Sony Deutschland GmbH
    Inventor: Jens Wildhagen
  • Patent number: 7363096
    Abstract: Essentially all of the processing parameters which control processing of a source audio signal to produce an encoded audio signal are stored in an audio processing profile. Multiple audio processing profiles are stored in a processing profile database such that specific combinations of processing parameters can be retrieved and used at a later time. Audio processing profiles are organized according to specific delivery bandwidths such that a sound engineer can quickly and efficiently encode audio signals for each of a number of distinct delivery media. Synchronized A/B switching during playback of various encoded audio signals allows the sound engineer to detect nuances in the sound characteristics of the various encoded audio signals.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: April 22, 2008
    Assignee: Microsoft Corporation
    Inventors: Philip R. Wiser, Leeann Heringer, Gerry Kearby, Leon Rishniw, Jason S. Brownell
  • Publication number: 20080069385
    Abstract: A method of amplification includes amplifying an input signal with a predetermined or user adjustable maximum gain to produce a second signal and compressing the dynamic range of the second signal with an automatic gain control to produce an output signal. The compression ratio of the automatic gain control is greater than one for output signals below a predetermined threshold output signal level and is essentially one for output signals above the predetermined threshold output signal level. The compression ratio may be predetermined or the method may include determining the compression ratio of the automatic gain control. The compression ratio may be determined according to the amplitude of the output signal or according to an input-output curve. The input-output curve my be predetermined and may be selected according to the auditory needs of a listener. Preferably the input-output curve is determined according to the predetermined or user adjustable maximum gain.
    Type: Application
    Filed: September 18, 2007
    Publication date: March 20, 2008
    Applicant: Revitronix
    Inventor: Lawrence Jay Revit
  • Patent number: 7343019
    Abstract: A normalization for streaming digital audio signals applies a gain factor according to the maximum sample magnitude in a window of samples and compare the gain factor to prior gain factors to adjust the gain factor for the samples in the window of samples. Adaptation of the gain factor with rapid decreases but slow increases avoids saturation but allows quiet passages.
    Type: Grant
    Filed: July 25, 2002
    Date of Patent: March 11, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy C. Hankins, Thomas Millikan, Christopher A. Scarr, Jason Kridner, Gabriel Dagani
  • Patent number: 7340069
    Abstract: A system and method for automatically controlling gain in a signal chain are presented. A first signal is processed to produce a processed signal. A gain is adjustably applied to the processed signal using an automatic gain control (AGC) mechanism. A resulting signal is produced. The gain is adjusted based on the first signal. As such, even when a desired signal is not substantially present in the first signal, gain is not excessively applied to the processed signal.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: March 4, 2008
    Assignee: Intel Corporation
    Inventor: Arthur E. Sheiman
  • Publication number: 20080044039
    Abstract: An audio signal processing method includes: controlling the volume of a digital audio signal according to a latest value of an adaptive gain value which is adjustable; detecting whether data carried by the digital audio signal satisfies a specific criterion and utilizing a pendulum counter to count a number of times the data carried by the digital audio signal satisfies the specific criterion; if the counter value of the pendulum counter reaches an upper bond, selectively decreasing the adaptive gain value according to a decrement to decrease the volume of the digital audio signal; and if the counter value of the pendulum counter reaches a lower bond, selectively increasing the adaptive gain value according to an increment to increase the volume of the digital audio signal, where the magnitude of the decrement and the magnitude of the increment are different from each other.
    Type: Application
    Filed: August 16, 2007
    Publication date: February 21, 2008
    Inventors: Chung-Ko Chiu, Hung-Chuan Wei, Che-Wei Liao, Po-Chang Ho
  • Patent number: 7330554
    Abstract: A volume control apparatus and a method enable the volume of sound output from a sound output system to be adjusted in units of an increase/decrease interval set by a user, the volume control apparatus controlling the volume of sound output from the sound output system on a basis of volume level information set by the user.
    Type: Grant
    Filed: June 24, 2003
    Date of Patent: February 12, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hyun-sig Lim, Eun-young Kim
  • Publication number: 20080025528
    Abstract: A noise reduction system is used in a BTSC system to reduce noise of an audio signal. The noise reduction system has an audio spectral compressing unit that has a filter and a memory in the approach of the digital processing. The filter is arranged to filter an input signal according to a transfer function, a variable d, and several parameters b0/a0, a0/b0, b1/b0 and a1/a0. The memory is arranged to store the parameters.
    Type: Application
    Filed: July 27, 2006
    Publication date: January 31, 2008
    Applicant: Himax Technologies, Inc.
    Inventors: Kai-Ting Lee, Tien-Ju Tsai
  • Publication number: 20080025530
    Abstract: A method and apparatus for limiting an audio signal by establishing a maximum magnitude level that is responsive to a volume control and limiting a reproduced sound to that maximum allowable magnitude level. Limiting circuitry may include analog and digital solutions and may be executed through soft-limiting, hard-limiting, or a combination thereof. A limiter may include circuitry to dynamically detect peak levels in an audio signal. A desired gain may be associated with the audio signal and, if applied, produces a desired peak. This desired peak may be compared to the maximum magnitude level, which may be set relative to a peak acoustic capacity. Audio signal amplification may be set in response to this comparison, such as scaling gain by a ratio of desired peak to maximum magnitude level.
    Type: Application
    Filed: July 26, 2006
    Publication date: January 31, 2008
    Inventor: Eric Douglas Romesburg
  • Patent number: 7319761
    Abstract: The invention describes a graphical method for detecting and adjusting audio overload conditions. The graphical user interface provides a user complete playback control of several audio tracks, detection of overload conditions such as audio clipping, and graphical methods to correct the overload conditions. The graphical interface provides drag handles which the user can use to adjust the various characteristics of an audio file. The characteristics, such as amplitude and temp, may be adjusted as a function of time.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: January 15, 2008
    Assignee: Apple Inc.
    Inventors: Curt Bianchi, Nikhil Bhatt, Christopher Moulios
  • Patent number: 7317800
    Abstract: A circuit for processing an input audio signal received at an input of the circuit provides a processed audio signal at a circuit output. The circuit includes first and second conductive paths through which the received audio signal travels. The audio signal is processed such that harmonics of the signal components with a low-frequency are generated in the second path and are admixed to the signal in the first path. In the second path the audio signal is sequentially bandpass filtered, weighted with a correction factor, amplified, limited to a predetermined value, and bandpass filtered, where the correction factor is reduced when the predetermined value is exceeded.
    Type: Grant
    Filed: May 26, 2000
    Date of Patent: January 8, 2008
    Assignee: Micronas GmbH
    Inventors: Matthias Vierthaler, Martin Winterer
  • Patent number: 7305100
    Abstract: The present invention relates to a hearing aid with a compressor having a low and gain independent delay and low power consumption. The hearing aid comprises a multi-channel compressor for compensation of dynamic range loss and with a digital input for inputting a digital sound signal, and an output connected to an amplifier with a selectable gain as a function of frequency for compensation of frequency dependent hearing loss, and connected to an output for outputting the processed digital sound signal.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: December 4, 2007
    Assignee: GN ReSound A/S
    Inventor: Brian Dam Pedersen
  • Patent number: 7305346
    Abstract: A volume adjustment unit reduces the volume of audio data. By coding the audio data where the volume is reduced in advance, the possibility of being decoded in a manner of exceeding the maximum bit number at a reproduction-side apparatus is reduced. Thus, the volume adjustment unit needs to reduce the volume of the audio data during a processing at a data input unit up to a quantization coding unit, that is, before the end of quantizing, based on a compression ratio.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: December 4, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tatsushi Oyama, Hideki Yamauchi
  • Publication number: 20070258603
    Abstract: A frequency band of an audio input signal is analyzed to determine if a transient is present. When transients are detected, modifications are made to the intensity levels corresponding to the frequency band for a brief time period.
    Type: Application
    Filed: May 4, 2007
    Publication date: November 8, 2007
    Applicant: CREATIVE TECHNOLOGY LTD
    Inventors: Carlos Avendano, Jean Laroche, Michael M. Goodwin
  • Patent number: 7274795
    Abstract: The present invention relates to novel systems, methods, and circuits useful for achieving quality sound presentation in high-noise environments. Specifically, the present invention provides systems, methods, and circuits for processing audio signals. The present invention further provides methods for hard-programming adjustments into a multi-band equalizer that compensates for anomalies associated with an anticipated listening environment.
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: September 25, 2007
    Inventor: Anthony Bongiovi
  • Patent number: RE40960
    Abstract: An expander circuit for decoding audio signals which were encoded in accordance with the BTSC multichannel sound system standard including DBX commanding is presented. A wideband expander circuit is utilized and a DBX expander can be accommodated. The wideband expander circuit is provided with a signal path having an input LPF (low pass filter), a stereo difference signal (L?R) demodulator, a second LPF, and a voltage controlled amplifier (VCA), the gain of which is controlled by a control signal derived from the demodulated difference signal which has been operated on by a bandpass filter (BPF) and an integrating peak detector. The output of the VCA is provided to a deemphasis network before being fed to a decoder matrix for combining with the sum stereo signal (L+R) for reconstructing the original L and R signals.
    Type: Grant
    Filed: May 5, 2005
    Date of Patent: November 10, 2009
    Assignee: Thomson Licensing
    Inventor: David Lawrence Albean