Binaural And Stereophonic Patents (Class 381/1)
  • Patent number: 6925184
    Abstract: The present invention provides a method to convert the conventional two-channel uncoded audio system into multichannel system. There is no coding/decoding procedure in the invention, but just process the phases of the original two audio channels to provide different audio sources for surrounding distribution and achieve the best effect of reproducing the original audios. The present invention also provides an audio processor for implementing the method.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: August 2, 2005
    Assignee: Princeton Technology Corp.
    Inventor: Ko-Kang Wang
  • Patent number: 6925426
    Abstract: A local performance simulation system simulates an ensemble sound pattern. The simulation system includes a signal generation system for simultaneously generating contact recording signals based on vibrations from the ensemble, where the ensemble produces an ensemble sound pattern. A signal processing system channelizes the contact recording signals and generates final instrument signals based on the channelized contact recording signals. The simulation system further includes a reproduction system with dedicated loudspeaker systems for generating audible sound waves based on the final instrument signals, where the sound waves simulate the ensemble sound pattern. Contact recording the vibrations and channelizing the contact recording signals eliminates all reverberation and reflection effects of the recording environment from the contact recording signals.
    Type: Grant
    Filed: February 22, 2000
    Date of Patent: August 2, 2005
    Assignee: Board of Trustees operating Michigan State University
    Inventor: William M. Hartmann
  • Patent number: 6868161
    Abstract: A transmitting/receiving device and a transmitting/receiving method for transmitting and receiving an acoustic signal through infrared radiation or the like are obtained wherein noise and interruption of the sound due to overmodulation of a transmitting device in compressing/expanding and transmitting the acoustic signal are not generated. In a transmitting/receiving device or a transmitting/receiving method having a receiving device for receiving a signal wireless-transmitted from a transmitting device, demodulating the signal to obtain an analog signal, and outputting the signal, wherein an analog acoustic signal input into the transmitting device is digitized, subjected to signal processing, analog-converted, and output. In the signal processing, the input digital signal is delayed and a level of the delay output signal is compressed or expanded according to a level of the input signal.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: March 15, 2005
    Assignee: Sony Corporation
    Inventors: Yuji Yamada, Hirofumi Kurisu
  • Patent number: 6862356
    Abstract: A dummy listener and right and left speakers 13 and 14 are disposed in an anechoic room as a model of the layout of those a car cabin 15 or the like. Transfer functions ALL, ALR, ARL and ARR in a space ranging from the speakers 13 and 14 to the right and left ears of a listener 16 in a car cabin 15 or the like are calculated from impulse response series aLL(t) to aRR(t) obtained when pulse sounds are respectively emitted from the speakers 13 and 14. A correction circuit 10b contains correction transfer functions H11, H12, H21 and H22, which are obtained by an inverse matrix of a 2-row and 2-column regular matrix of which the elements are the transfer functions ALL, ALR, ARL and ARR. Audio signals SL and SR on which head related transfer functions are superimposed are applied to the correction circuit 10b, and the output signals of the correction circuit 10b are supplied to the speakers 13 and 14.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: March 1, 2005
    Assignee: Pioneer Corporation
    Inventor: Atsushi Makino
  • Patent number: 6853869
    Abstract: A surround-sound circuit has a delay time memory (31) for storing a digital audio input signal IN, and outputs the stored input signal as a surround-sound signal a predetermined time later. The input signal is compressed by a compressor (32) in the form of ADPCM encoder before it is stored in the memory (31), and the compressed signal retrieved from the memory is expanded by an expander (33) in the form of ADPCM decoder before it is added to the input signal. The invention may reduce appreciably the amount of data to be stored in the memory, and hence the storage capacity of the RAM, without directly loping the audio input signal IN and hence avoiding appreciable deterioration of the signal IN.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: February 8, 2005
    Assignee: Rohm Co., Ltd.
    Inventor: Kei Nishioka
  • Patent number: 6842524
    Abstract: To provide a method for localizing sound image of reproducing sound outside right and left speakers, by processing and controlling audio signals which allows sound image localization outside the speakers for reproducing the controlled audio signals by means of a very concise hardware architecture. When the audio signals 1L, 1R of right and left channels recorded on fit media for stereophonic reproduction are reproduced, process to emphasize a factor of a sense of direction that listener's hearing has is applied by delaying phase characteristic of the audio signals 1L, 1R without change of frequency characteristics with increase in frequency to drive the speakers 7L , 7R of right and left channels.
    Type: Grant
    Filed: May 26, 2000
    Date of Patent: January 11, 2005
    Assignees: OpenHeart Ltd., A Limited Responsibility Company, Research Network
    Inventor: Wataru Kobayashi
  • Publication number: 20040264703
    Abstract: When a plug of a monaural microphone is connected to an external microphone input section, a right channel terminal is connected to a GND terminal, and a voltage Vdet will be a GND potential. A DC voltage detection section detects this GND potential, and outputs, for example, an H level signal as a detection signal. In response to this detection signal, a system control section controls a DSP so that, for example, an audio signal of the left channel is recorded by use of both right and left recording channels.
    Type: Application
    Filed: March 17, 2004
    Publication date: December 30, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Atsushi Fujita
  • Publication number: 20040258246
    Abstract: The invention relates to an apparatus (1) for amplifying bass frequencies of an audio signal (AL, AR). The bass components are applied to a controllable amplifier (17).
    Type: Application
    Filed: April 14, 2004
    Publication date: December 23, 2004
    Inventor: Loic Bernard Tanghe
  • Publication number: 20040252852
    Abstract: The present invention, generally speaking, picks up a voice or other sound signal of interest and creates a higher voice-to-background-noise ratio in the output signal so that a user enjoys higher intelligibility of the voice signal. In particular, beamforming techniques are used to provide optimized signals to the user for further increasing the understanding of speech in noisy environments and for reducing user listening fatigue. In one embodiment, signal-to-noise performance is optimized even if some of the binaural cues are sacrificed. In this embodiment, an optimum mix ratio or weighting ratio is determined in accordance with the ratio of noise power in the binaural signals. Enhancement circuitry is easily implemented in either analog or digital form and is compatible with existing sound processing methods, e.g., noise reduction algorithms and compression/expansion processing. The sound enhancement approach is compatible with, and additive to, any microphone directionality or noise cancelling technology.
    Type: Application
    Filed: March 29, 2004
    Publication date: December 16, 2004
    Inventor: Jon C. Taenzer
  • Publication number: 20040247132
    Abstract: An acoustic correction apparatus processes a pair of left and right input signals to compensate for spatial distortion as a function of frequency when the input signals are reproduced through speakers in a sound system. The sound-energy of the left and right input signals is separated and corrected in a first low-frequency range and a second high-frequency range. The resultant signals are recombined to create image-corrected audio signals having a desired sound-pressure response when reproduced by the speakers in the sound system. The desired sound-pressure response creates an apparent sound image location with respect to a listener. The image-corrected signals may then be spatially enhanced to broaden the apparent sound image.
    Type: Application
    Filed: January 22, 2004
    Publication date: December 9, 2004
    Inventors: Arnold I. Klayman, Alan D. Kraemer
  • Publication number: 20040218764
    Abstract: The system of the present invention includes, briefly, a point source speaker system, comprising a processor which produces a left minus right (L−R) audio signal, a right plus left (R+L) and a right minus left (R−L) audio signal; three speakers each for audibly transmitting one of the L−R, R+L and R−L audio signals; and a point source speaker enclosure for housing the three speakers in a single enclosure.
    Type: Application
    Filed: May 24, 2004
    Publication date: November 4, 2004
    Applicant: Kentech Interactive
    Inventor: Francis Allen Miller
  • Publication number: 20040213412
    Abstract: A stereo sounding method which can provide realistic sounds such as stereo sounds for a large number of listeners while reducing the number of speakers. A stereo sounding system is comprised of a plurality of stereo sound sources, and a plurality of speakers. A smaller number of speakers than twice the number of the plurality of stereo sound sources are arranged, and an R-channel output from at least one stereo sound source among the plurality of stereo sound sources and an L-channel output from a stereo sound source other than the at least one stereo sound source are mixed, and the mixing result is output to at least one of the arranged speakers.
    Type: Application
    Filed: April 28, 2004
    Publication date: October 28, 2004
    Inventors: Yoshiki Nishitani, Kenichi Miyazawa, Akira Miki, Kenji Ishida
  • Publication number: 20040213411
    Abstract: A reproducing time until audio data is transmitted to a speaker (300) connected in a wireless transmission system is converted into a sound travel distance. A computing section (213F) performs delay processing so that the audio data transmitted for a shorter distance becomes equal to the one for a longer distance based on a parameter information on a delay time of a data area stored in a memory (213E) when comparing the sum of the sound travel distance and another locating distance to the speaker (300) from a reference point and a locating distance of the speaker in a wired transmission system. Image data is also delayed corresponding to a maximum delay time of the audio data so as to reproduce the image data on a display (400).
    Type: Application
    Filed: April 21, 2004
    Publication date: October 28, 2004
    Applicant: PIONEER CORPORATION
    Inventor: Kei Sakagami
  • Patent number: 6804358
    Abstract: A sound image localization processor comprises a first processing circuit 10 receiving a sound left signal and comprising a first delay unit 11 and a first sound image localization filter 12, a second processing circuit 20 receiving a surround right signal and comprising a second delay unit 21 and a second sound image localization filter 22, an adder 1 for adding the surround left signal and an output signal of the second processing circuit 20 and outputting the result of the addition as a voice signal to a left loudspeaker located ahead of a listener, and an adder 2 for adding the surround right signal and an output signal of the first processing circuit 10 and outputting the result of the addition as a voice signal to a right loudspeaker located ahead of the listener.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: October 12, 2004
    Assignee: Sanyo Electric Co., LTD
    Inventor: Seiji Kawano
  • Publication number: 20040196991
    Abstract: The present invention relates to a sound image localizing apparatus for generating a sound image localized in an arbitrarily set three-dimensional direction. The sound image direction setting unit (111) is operable to set a three-dimensional direction to which the sound image is to be localized in accordance with a listener's instruction; the angle conversion unit (112) is operable to convert the direction into a lateral angle (&agr;) and a rising angle (&bgr;), each of which serves as a cue for the listener to perceive the direction. The convolution operation unit 116 is operable to obtain lateral angle control information corresponding to the lateral angle (&agr;) from the lateral angle control information storage unit (113), a listener's front direction head-related impulse response from the front direction head-related impulse response storage unit (115), and rising angle difference information corresponding to the rising angle (&bgr;) from the rising angle difference information storage unit (114).
    Type: Application
    Filed: January 20, 2004
    Publication date: October 7, 2004
    Inventors: Kazuhiro Iida, Kazuhiro Nakamura
  • Publication number: 20040190384
    Abstract: A multi-jack detector for detecting states of a plurality of jacks. Each jack comprises a first switch having a first normally closed terminal and a first output terminal. The multi-jack detector comprises a plurality of bias resistors each coupled to one of the first output terminals, respectively; a control unit for determining the states of the plurality of jacks; wherein the first normally closed terminals are commonly coupled to a first node and the control unit determines the states of the plurality of jacks according to a voltage at the first node. Because the voltage at the first node is different for each state of the jacks, the detector can detects the states of the jacks using a single I/O pin.
    Type: Application
    Filed: February 12, 2004
    Publication date: September 30, 2004
    Inventors: Ming-Jane Hsieh, Chuting Su, Yi-Shu Chang, Ming-Lih Lin
  • Patent number: 6798887
    Abstract: A key click masker and method for disguising key clicks protect sensitive information by randomly varying key click echo generated by a computer system. The key click masker and method disguise the actual keystrokes by generating sounds that would confuse a listener trying to determine the actual keystrokes entered by a user while the user is inputting sensitive information on an input device.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: September 28, 2004
    Assignee: International Business Machines Corporation
    Inventor: Robert Floyd Andre
  • Patent number: 6795556
    Abstract: Original head-related transfer functions (HRTFs) are modified for a non-standard dimensioned head. The HRTF includes a near-ear response function, a far-ear response function, and an inter-aural time delay (ITD). The modified HRTF resembles an HRTF approximating that derived for a listener having different head and/or ear dimensions to the standard dimensions. The ITD value of the HRTF is multiplied by a given scaling factor independent of frequency. The near ear and/or far ear response function of the HRTF is multiplied by a constant scaling factor in the frequency domain independent of time delay, to expand or compress the functions in the frequency domain. The near ear and/or far ear response function of the HRTF are provided with a positive or negative offset value in the frequency domain. The amplitude of the near ear and/or far ear response function of the original HRTF(s) is (are) multiplied by a given gain factor.
    Type: Grant
    Filed: May 25, 2000
    Date of Patent: September 21, 2004
    Assignee: Creative Technology, Ltd.
    Inventors: Alastair Sibbald, Richard David Clemow, Michael Percy
  • Publication number: 20040179693
    Abstract: The invention is a crosstalk canceler wherein different frequency bands are canceled at different locations so as to allow greater listener movement about the “sweet spot” while maintaining effective crosstalk cancellation. A spectrally smooth canceler equalization is used, reducing artifacts for listeners away from the sweet spot and further enlarging the sweet spot. Finally, the canceler equalization is adapted to either the anticipated or the actual crosscoherence among the input channels, producing a natural equalization regardless of the input.
    Type: Application
    Filed: October 21, 2003
    Publication date: September 16, 2004
    Inventor: Jonathan S. Abel
  • Patent number: 6788789
    Abstract: A phase-conversion surround circuitry gives surround effects to right- and left-channel audio signals. An audio difference signal between the right- and left-channel audio signals is delayed at a specific time constant. The delayed audio difference signal is combined with the right- and left-channel audio signals, thus composite audio signals being generated. The time constant is periodically varying under oscillation at frequency of 12 Hz or less.
    Type: Grant
    Filed: November 15, 2002
    Date of Patent: September 7, 2004
    Assignee: Victor Company of Japan, Ltd.
    Inventor: Kazuhito Otsuka
  • Patent number: 6782308
    Abstract: In a music information reproducing device 1, a music information reproducing unit 2 reads a music information file 6 stored in a storage unit 4 and reproduces it as consecutive audible sound signal to sound audible sounds from a loud speaker 5. The music information file 6 comprises predetermined music information that a robot can recognize by analyzing as an audible sound signal and that specifies a movement pattern data for making the robot perform a movement pattern and normal music information for reproducing music. The robot 2 is a human form or an animal form robot that moves each part of the robot 2 in accordance with the specified movement pattern. A robot that performs a movement pattern along music by inputting the music as an audible sound signal and a movement pattern control program of the robot is provided in a cheap price.
    Type: Grant
    Filed: October 4, 2002
    Date of Patent: August 24, 2004
    Assignee: Yamaha Corporation
    Inventor: Atsushi Yamaura
  • Publication number: 20040161117
    Abstract: The invention relates to a method for at least two audio signals (A1, A2) each being impressed with a process function, particularly a transformation function. According to the invention, upper values (8) of a function-impressed audio signal (A3) are decreased after the function by a rate and subsequently all values (8, 9) of the partially decreased signal (A4) are increased.
    Type: Application
    Filed: January 14, 2004
    Publication date: August 19, 2004
    Inventors: Roelof E Reusens, Jean-Christophe Lallemand, Raf Coomans, Sandrine Laurence Yael Resler
  • Publication number: 20040161114
    Abstract: A filter circuit is composed of FIR filters, and the filter factor is of a symmetrical type, thereby realizing a linear phase characteristic and preventing phase distortion even if a desired frequency band is emphasized. The first filter factors of a low-pass filter are determined so that the first filter factors may be the terms of a sequence in which the sum of the terms is not zero, the sign of the sum of every other terms is the same as that of the other every other terms, and the sum of the every other terms is equal to that of the other every other terms. Thus, by only changing a part of the signs of the filter factors, second filter factors of a high-pass filter can be simply determined so that they may be the terms of a sequence in which the sum of the terms is zero, the sign of the sum of every other terms is opposite to that of the other every other terms, and the absolute value of the sum of the every other terms is equal to that of the other every other terms.
    Type: Application
    Filed: February 27, 2004
    Publication date: August 19, 2004
    Applicant: NEURO SOLUTION CORP.
    Inventor: Yukio Koyanagi
  • Patent number: 6777718
    Abstract: A semiconductor optical device includes a substrate, an optical waveguide layer on the substrate and having well and barrier layers. The semiconductor optical device also includes an optical absorbing layer on the substrate and adjacent to the optical waveguide layer so that incident light having an incident wavelength &lgr;LD is guided into the optical absorbing layer. Each of the well layers has a wavelength &lgr;g corresponding to the band gap of the well layers and that is larger than the incident wavelength &lgr;LD. Also, the band gap energy between base levels of a conduction band and a valence band of the optical waveguide layer is larger than the energy of the incident light having the incident wavelength &lgr;LD.
    Type: Grant
    Filed: February 4, 2003
    Date of Patent: August 17, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Kazuhisa Takagi
  • Publication number: 20040151330
    Abstract: The present invention has all the properties and capabilities of a standard direct-box, which is an audio adapter circuit in a rugged chassis. It allows high-impedance stereo headphones to be connected. It comes equipped with a switch that turns the signal to the exterior sound system on/off without interrupting sound to the headphones. The present invention also comes with a locking cover, which prevents inadvertent operation of additional switches, such as a ground lift switch or attenuation level switch. The cover also functions as a mounting structure.
    Type: Application
    Filed: February 4, 2003
    Publication date: August 5, 2004
    Inventor: John E. Lehmkuhl
  • Patent number: 6771778
    Abstract: The invention relates to a method for converting signals in two-channel stereo format to become suitable to be played back using headphones. The invention also relates to a signal processing device for carrying out said method. According to the invention left direct path (Ld) and left cross-talk path (LX) signals are formed from the left input signal (Lin), and correspondingly right direct path (Rd) and right cross-talk path (RX) signals are formed from the right input signal (Rin), and further the left output signal (Lout) is formed by combining said left direct-path (Ld) and said right cross-talk path (Rx) signals, and correspondingly, the right output signal (Rout) is formed by combining said right direct-path (Rd) and said left cross-talk path (Lx) signals.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: August 3, 2004
    Assignee: Nokia Mobile Phonés Ltd.
    Inventor: Ole Kirkeby
  • Publication number: 20040146166
    Abstract: The invention concerns a circuit for adapting the signals from different channels (L, R) delivered by an audio reproduction system (10) in conditions specific to headset listening.
    Type: Application
    Filed: October 18, 2003
    Publication date: July 29, 2004
    Inventor: Valentin Chareyron
  • Patent number: 6768798
    Abstract: A method of customizing the HRTF for each tested individual for providing all tested individuals an optimum audio experience by providing convincing and realistic three-dimensional sounds. Customization can be achieved by playing a series of sample sounds and having the tested individual locate where the sound is emanating from. In this way, the method can identify for each test subject which audible positional cues are most important, how frequency changes are interpreted as position, and what effects are most convincing and pleasurable. This information is used to effect the HRTF for each tested individual. The customized HRTF will then be applied to all three-dimensional sounds giving the listener an optimum audio experience.
    Type: Grant
    Filed: November 19, 1997
    Date of Patent: July 27, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Morgan James Dempsey
  • Publication number: 20040141619
    Abstract: The invention relates to a method of generating a left modified and a right modified audio signal for a stereo system from multichannel audio signals (XL, XR, XLS, XRS, and XC) with a left and a right channel and at least one further audio channel. According to the invention, the signal of the channel of highest energy is modified in a filter (1) with a transformation function in a first parallel branch (2) and is modified in a second filter (6) with a reverberation function in a second parallel branch (5), whereupon the modified signals are joined together in a summation unit (8).
    Type: Application
    Filed: November 24, 2003
    Publication date: July 22, 2004
    Inventor: Daniel Willem Elisabeth Schobben
  • Publication number: 20040141622
    Abstract: A method and apparatus is provided for presenting a user with a visual indication of the likely user-perceived location of sound sources in an audio field generated from left and right audio channel signals. To produce this visual indication, corresponding components in the left and right channel signals are detected by a correlation arrangement. These corresponding components are then used by a source-determination arrangement to infer the presence of at least one sound source and to determine the azimuth location of this source within the audio field. A display processing arrangement causes a visual indication of the sound source and its location to be presented to the user.
    Type: Application
    Filed: October 9, 2003
    Publication date: July 22, 2004
    Applicant: HEWLETT-PACKARD DEVELOPMENT COMPANY, L. P.
    Inventor: Robert Francis Squibbs
  • Publication number: 20040136549
    Abstract: An effects and recording system is provided which is capable of recording at least one of a received audio signal and a processed audio signal generated by the application of musical effects to the received audio signal. The audio signal may be captured from any device capable of producing an audio signal. The effects and recording system may provide various recording capabilities including auto track selection and arming, automatic signal routing, delayed recording initialization, automatic level setting and panning settings, editing capabilities, and the merging of recorded tracks. Additionally, the effects and recording system may provide various monitoring capabilities, including automatic level, panning, and/or effects or other filtering of signals recorded or monitored via the system, as well as an enhanced mix-down feature, and music mix-down type.
    Type: Application
    Filed: January 14, 2003
    Publication date: July 15, 2004
    Inventors: James D. Pennock, Peter Chaikin, Josh Kapp, John Hanson
  • Publication number: 20040136538
    Abstract: The invention provides a method for simulating a 3D sound environment in an audio system using an at least two-channel reproduction device, the method including generating first and second pseudo head-related transfer function (HRTF) data, first using at least one speaker and then using headphones; dividing the first and second frequency representation of the data or using a deconvolution operator on the time domain representation of the first and second data, or subtracting the cepstrum representation of the first and second data, and using the results of the division or subtraction to prepare filters having an impulse response operable to initiate natural sounds of a remote speaker for preparing at least two filters connectable to the system in the audio path from an audio source to sound reproduction devices to be used by a listener.
    Type: Application
    Filed: March 5, 2004
    Publication date: July 15, 2004
    Inventors: Yuval Cohen, Amir Bar On, Giora Naveh, Haim Levy
  • Publication number: 20040131205
    Abstract: Comprising:
    Type: Application
    Filed: December 18, 2003
    Publication date: July 8, 2004
    Inventor: Jose Ramon Labiaga Larrea
  • Publication number: 20040131212
    Abstract: An LCD display has a built-in audio processing device. The audio processing device receives audio signals from a piece of Audio/Video equipment and modulates the received audio signals. The modulated audio signals are further wirelessly emitted by infrared emitting diodes that are mounted in a position near the screen of the LCD display. When a user wears wireless earphones, the audio signals can be received and played by the earphones so people in the proximity of the LCD display will not be distracted by the sound.
    Type: Application
    Filed: February 19, 2003
    Publication date: July 8, 2004
    Inventor: Steven Chang
  • Publication number: 20040131192
    Abstract: A sound system for capturing and reproducing sounds produced by a plurality of sound sources. The system comprises a device for receiving sounds produced by the plurality of sound sources and converting the separately received sounds to a plurality of separate audio signals without mixing the audio signals. The system may further comprise a device for separately storing the plurality of separate audio signals on a recording medium without mixing the audio signals and a device for reading the stored audio signals from the recording medium. The system further includes a reproduction system for recreating the plurality of separate audio signals. Also, the system comprises an amplification network which comprises a plurality of amplifier systems, with one or more separate amplifiers in each amplifier system for separately amplifying each of the separate audio signals.
    Type: Application
    Filed: September 30, 2003
    Publication date: July 8, 2004
    Inventor: Randall B. Metcalf
  • Patent number: 6760446
    Abstract: The system of the present invention includes, briefly, a point source speaker system, comprising a processor which produces a left minus right (L−R) audio signal, a right plus left (R+L) and a right minus left (R−L) audio signal; three speakers each for audibly transmitting one of the L−R, R+L and R−L audio signals; and a point source speaker enclosure for housing the three speakers in a single enclosure.
    Type: Grant
    Filed: October 5, 2000
    Date of Patent: July 6, 2004
    Inventor: Francis Allen Miller
  • Patent number: 6754350
    Abstract: A surround reproducing circuit includes a first adder for generating a difference signal of an L signal and an R signal which are inputted, a low-pass filter connected to an output side of the first adder, and second and third adders for mixing an output signal of the low-pass filter as a surround signal with the L signal and the R signal in an opposite phase relationship to each other. Change in a phase is lessened within a frequency band of 20 Hz to 20 KHz and the localization can become definite, and furthermore, a harsh high pass is also lessened. Consequently, it is possible to realize a surround effect having natural spread. Furthermore, the number of capacitors to be required can also be decreased.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: June 22, 2004
    Assignee: New Japan Radio Co., Ind.
    Inventor: Yositugu Sugimoto
  • Publication number: 20040107016
    Abstract: A computer including HI-FI stereo is provided. The BIOS of the computer including HI-FI stereo in the embodiment includes a function menu that shows selections of HI-FI stereo and general-purpose computer when the computer including HI-FI stereo is just booted up. The HI-FI stereo function is set up bypassing the routine procedure that is used to activate the operating system of the computer unit and plays associated AV data immediately, while the operating system is activated for setting up a general-purpose computer if the general-purpose computer selection is selected.
    Type: Application
    Filed: October 9, 2003
    Publication date: June 3, 2004
    Inventor: Shyh-Dar Geeng
  • Patent number: 6738479
    Abstract: A method of audio signal processing for a loudspeaker located close to an ear in use, the method consisting of or including:- creating one or more derived signals from an original monophonic input signal, the derived signals being representative of the original signal being scattered by one or more bodies remote from said ear (excluding room boundary reflection or reverberation), combining the derived signal or signals with said input signal to form a combined signal, and feeding the combined signal to said loudspeaker, thereby providing cues for enabling the listener to perceive the source of the sound of the original monophonic input signal to be located remote from said ear.
    Type: Grant
    Filed: November 13, 2000
    Date of Patent: May 18, 2004
    Assignee: Creative Technology Ltd.
    Inventors: Alastair Sibbald, Max Andrew Little
  • Publication number: 20040091121
    Abstract: This invention may provide a headphone driving circuit needless of coupling condenser even if the power supply supplies a single output voltage. The headphone driving circuit comprises (1) a first amplifier to amplify a first composite signal generated by subtracting a second channel audio signal from a first channel audio signal, then driving one end of a first voice coil of a stereo-headphone, (2) a second amplifier to amplify a second composite signal generated by subtracting the first channel audio signal from the second channel audio signal, then driving one end of a second voice coil of the stereo-headphone, (3) a third amplifier to amplify a third composite signal generated by adding the first channel audio signal and the second channel audio signal for driving the other end of the first and the second voice coil of the stereo-headphone.
    Type: Application
    Filed: March 21, 2003
    Publication date: May 13, 2004
    Inventor: Masashi Morimoto
  • Patent number: 6735314
    Abstract: A stereophonic processing system provided with spatial expansion of the stereophonic sound so that a pair of spaced-apart loudspeakers will acoustically appear to be spaced apart further then they actually are. The spatial expansion circuit includes tonal compensation.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: May 11, 2004
    Assignee: Thomson Licensing S.A.
    Inventor: Alan Henderson Hoover
  • Publication number: 20040086128
    Abstract: A method and apparatus for creating a third signal channel from an input signal received in each of a first and second channel involves inverting a predetermined frequency range of signals in the first channel out of phase with a corresponding frequency range of signals in the second channel. Thereafter, the inverted signal in the first channel and the corresponding frequency signal in the second channel may be communicated to a speaker, which is bridged across the first and second channels, as the third signal channel. This speaker produces sound corresponding to the difference (i.e., the frequency range determined by the predetermined bandwidth of the inverted signal) between the inverted signal in the first channel and the corresponding frequency signal in the second channel.
    Type: Application
    Filed: November 1, 2002
    Publication date: May 6, 2004
    Inventors: Jon M. Risch, Emmett E. Heath
  • Publication number: 20040066937
    Abstract: A sound imaging system, which by processing left and right stereo channel audio signals of a conventional two channel stereo system, distributes signals to a speaker array of a number of speakers determined by a listening area. Listeners located in different places within the listening area, can have an audible perception of an equivalent distribution to that of the conventional two channel stereo system. Additionally they will have an audible central perception of the centered program material equivalent to that obtained from the conventional two channel stereo system when the listeners are located in a median plane of the conventional two channel stereo system speakers.
    Type: Application
    Filed: October 8, 2002
    Publication date: April 8, 2004
    Inventor: Juan Serrano
  • Patent number: 6718039
    Abstract: An acoustic correction apparatus processes a pair of left and right input signals to compensate for spatial distortion as a function of frequency when the input signals are reproduced through speakers in a sound system. The sound-energy of the left and right input signals is separated and corrected in a first low-frequency range and a second high-frequency range. The resultant signals are recombined to create image-corrected audio signals having a desired sound-pressure response when reproduced by the speakers in the sound system. The desired sound-pressure response creates an apparent sound image location with respect to a listener. The image-corrected signals may then be spatially-enhanced to broaden the apparent sound image.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: April 6, 2004
    Assignee: SRS Labs, Inc.
    Inventors: Arnold I. Klayman, Alan D. Kraemer
  • Publication number: 20040062401
    Abstract: A process for translating M audio input channels representing a soundfield to N audio output channels representing the same soundfield, wherein each channel is a single audio stream representing audio arriving from a direction, M and N are positive whole integers, and M is at least 2, generates one or more sets of output channels, each set having one or more output channels. Each set is associated with two or more spatially adjacent input channels and each output channel in a set is generated by a process that includes determining a measure of the correlation of the two or more input channels and the level interrelationships of the two or more input channels.
    Type: Application
    Filed: August 5, 2003
    Publication date: April 1, 2004
    Inventor: Mark Franklin Davis
  • Patent number: 6714652
    Abstract: A system and method are described for rendering a left rear surround input signal at a left rear virtual speaker location and rendering a right rear surround input signal at a right rear virtual speaker location. The method includes phase shifting the left rear surround input signal by a first phase shift. The right rear surround input signal is phase shifted by a second phase shift. The phase shifted left rear surround input signal is phase shifted using an HRTF selected to render the left rear surround input signal at the left rear virtual speaker location. The phase shifted right rear surround input signal is transformed using an HRTF selected to render the right rear surround input signal at the right rear virtual speaker location.
    Type: Grant
    Filed: October 3, 2000
    Date of Patent: March 30, 2004
    Assignee: Creative Technology, Ltd.
    Inventors: Stephen A. Davis, Martin Walsh, David Berners
  • Patent number: 6711268
    Abstract: A stereo headphone employing a standard stereo headphone plug is adapted for automatically hearing a monaural signal at both earpieces, when accessing a typical monaural source. In the first embodiment of the invention, an impedance element couples the signal from a first acoustical driver that receives the monaural signal from the stereo plug tip, to a second acoustical driver that is connected to the stereo plug ring and normally receives no signal when plugged into a conventional monaural audio source output jack. The magnitude of the coupling impedance is selected with respect to the impedance of the acoustical driver so that the reduction in loudness at the second earpiece due to the signal voltage drop across the coupling impedance is not perceptible to the listener. This will occur when the reduction in loudness at the second earpiece is less than the threshold of perceivable loudness reduction at one ear when there is no reduction in loudness at the other ear.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: March 23, 2004
    Assignee: Enztec Audio Ltd.
    Inventors: Arthur Barry Colegrave, Richard Goldstein
  • Patent number: 6707917
    Abstract: A monaural and stereo audio signal control system for use in cable-signal set-top boxes selects signal processing paths as a function of the monaural and stereo nature of the incoming audio component of the television signal and an indication as to whether the audio component is a “clear” or “masked” signal. A clear audio signal is a signal that conforms to a NTSC or BTSC standard that can be processed by a conventional television receiver while a “masked” signal is one in which the carrier frequency has been changed or otherwise modified so that a conventional television receiver cannot extract the audio content. A signal-processing path is provided for conventional clear monaural and stereo audio and for a masked monaural signal and for a masked stereo signal.
    Type: Grant
    Filed: June 9, 1999
    Date of Patent: March 16, 2004
    Assignee: General Instrument Corporation
    Inventors: Henry S. Landgraf, Anthony Troiano, Dipakkumar R. Patel
  • Patent number: 6700980
    Abstract: The invention relates to a method for synthesizing a virtual sound source in a system (40) which comprises at least a right and a left channel for transmitting a stereo signal and in which the channels are connected to a filter block (42) for expanding the sound image. In the method, the amplifications of the separated monophonic and stereophonic signal components are optimized according to the stereophony of the signal coming to the system. The method according to the invention can also be applied to producing early room reflections by means of a separate filter block (71). The invention also relates to a device for synthesizing a virtual sound source, which device comprises at least a first and a second channel for transmitting the signal, at least one amplifier and filter and means for estimating the stereophony of the signal, for determining the amplification coefficient of the filtered signal and for controlling the amplifier according to the calculated amplification coefficient.
    Type: Grant
    Filed: May 5, 1999
    Date of Patent: March 2, 2004
    Assignee: Nokia Display Products Oy
    Inventors: Matti Sakari Hämäläinen, Jukka Holm
  • Publication number: 20040039464
    Abstract: An error concealment method for multi-channel digital audio involves receiving an audio signal having audio data forming a first audio channel and a second audio channel included therein, wherein the first and second audio channels are correlated with each other in a manner so that a spatial sensation is typically perceived when listened to by a user. Erroneous first-channel data is detected in the first audio channel, and second-channel data is obtained from the second audio channel. The erroneous first-channel data of the first audio channel is corrected by using the second-channel data. Upon detection of the erroneous first-channel data, a spatially perceivable inter-channel relation between the first and second audio channels is determined, and the determined inter-channel relation is used when correcting the erroneous first-channel data of the first audio channel so as to preserve the spatial sensation perceived by the user.
    Type: Application
    Filed: June 13, 2003
    Publication date: February 26, 2004
    Applicant: Nokia Corporation
    Inventors: Jussi Virolainen, Ari Lakaniemi