Abstract: An apparatus for effecting sound stage expansion in an audio system presenting two sound channels includes: (a) A first signal source coupled for providing at least one first signal representing a first sound channel to at least one first input locus of a first amplifying unit. The first amplifying unit participates in presenting the first sound channel. (b) A second signal source coupled for providing at least one second signal representing a second sound channel to at least one second input locus of a second amplifying unit. The second amplifying unit participates in presenting the second sound channel. (c) At least one first filter unit coupling the first signal source with at least one of the at least one second input locus. (d) At least one second filter unit coupling the second signal source with at least one of the at least one first input locus.

Abstract: Two-channel input audio signals are processed to construct output audio signals by decomposing the two-channel input audio signals into a plurality of two-channel subband audio signals. Separately, in each of a plurality of subbands, at least three generated subband audio signals are generated by steering the two-channel subband audio signals into at least three generated signal locations. The output audio signals are synthesized from the generated subband audio signals. The steering applies differing construction rules in at least two of the plurality of subbands.

Abstract: In accordance with some embodiments of the present invention there is provided a system, a method and a circuit for processing a stereo audio signal. According to some embodiments, the system for processing a stereo audio signal may include an audio processing circuit. The audio processing module or circuit may be operatively connected to an audio input interface and to an output audio interface. Through the audio input interface, the audio processing circuit may be adapted for receiving a 2-channels stereo audio signal. The audio processing module may be adapted for determining an output mono audio signal representing the center sound and a stereo audio signal representing the stereo sound without the center. Through the output interface the audio processing circuit may provide each of an output mono audio signal representing the center sound and a stereo audio signal representing the stereo sound without the center.

Abstract: An audio system including a rendering processor for separately rendering a dialogue channel and a center music channel. The audio system may include circuitry for extracting one or both of the dialogue channel or the center music channel from program material that does not include both a dialogue channel and a center music channel. The dialogue channel and the center music channel may be radiated with different radiation patterns.

Abstract: A center channel positioning apparatus is provided, which does not cause strange feeling in sound quality even at a position apart from an original listener position. A sound signal processing unit (40) changes a phase of at least one of a left sound signal for center channel positioning (CL) and a right sound signal for center channel positioning (CR), based on a processing coefficient, and causes a left speaker (46) and a right speaker (52) to output sound based on a center channel sound signal (C). The processing coefficient is calculated based on the difference in level between both ears in the case where the left sound signal for center channel positioning (CL) for the left speaker (46), and the right sound signal for center channel positioning (CR) for the right speaker (52) are reproduced simultaneously.

Abstract: A transmission signal processing device 10 includes a transmission signal data demultiplexing circuit RX for receiving multiplexed transmission signal data and demultiplexing the transmission signal data into video signal data and multi-channel audio signal data, a decoder circuit 100 for decoding the multi-channel audio signal data to obtain a plurality of multi-channel audio signal data including at least front center channel audio signal data, and a transmission signal data multiplexing circuit TX for multiplexing the video signal data and the front center channel audio signal data to obtain output transmission signal data.

Abstract: The invention relates to a method of processing an input signal into a phantomized signal, including adding at least one attenuated delayed signal to the input signal, the phantomized signal having at least one delayed attenuated signal and the input signal. A phantomized signal according to the invention offers a new and impressive integration of a center channel signal of a multi channel audio system into the complete audio image provided by the system.

Abstract: For synthesizing at least three output channels using two stereo input channels, the stereo input channels are analyzed to detect signal components occurring in both input channels. A signal generator is operative to introduce at least a part of the detected signal components into the second channel associated with a second speaker in an intended speaker scheme, which is positioned between a first and a third speaker in the speaker scheme. When, however, feeding of the complete detected signal components would result in a clipping situation, then only a part of the detected signal components is fed into the second channel as a real center channel and the remainder is located in the first and third channels as a phantom center channel.

Abstract: A system and method for processing multiple channel audio signals to create a realistic soundscape in a space largely independent of the number of loudspeakers and audio source channels is provided. The system includes an encoding system in the recording process and a decoding system in the local listening area.

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.

Abstract: The method and system of present invention sequences audio post-processing algorithms to simulate live or theater sound. An audio signal is selectively post-processed according to equipment availability and listener preferences. Downmixing or Prologic algorithms are applied to a signal arriving at sound system. A listener inputs their speaker configuration to a player console. Desired post-processing effects are likewise indicated to the console. For instance, if surround sound equipment is both available and selected, then surround portions of the audio signal are parsed to surround speakers. Bass management techniques then transfer low frequency channels of the signal to compatible speakers. VES or DCS algorithms further manipulate the surround portion of the signal to create an illusion of immersion, and a center channel equalizer balances the signal playback. Alternatively, the post-processed signal is transmitted to a headphone set.

Abstract: An audio upmixer, such as a two-channel to three-channel upmixer, employs a difference in a measure of sound at the ears of a listener in accordance with first and second models, one based on a reproduction of the original channels and the other based on a reproduction of the upmixed channels. The difference is minimized while simultaneously causing a, portion of one or more of the stereophonic channels to be applied to the center loudspeaker under some conditions of the signals in the stereophonic channels, the portion being commensurate with the value of a weighting factor, such that the weighting factor controls a balance between two opposing conditions, one in which no signals are applied to the center loudspeaker and another in which no signals are applied to the left and right loudspeakers.

Abstract: A method of disassembling a pair of input signals L(t) and R(t) to form subband representations of N output channel signals o1(t), o2(t), . . . , oN(t), wherein t is time. The method includes the steps of generating a subband representation of the signal L(t) containing a plurality of subband components Lk(t) where k is an integer ranging from 1 to M; generating a subband representation of the signal R(t) containing a plurality of subband components Rk(t); and constructing the subband representation for each of the plurality of output channel signals, each of those subband representations containing a plurality of subband components oj,k(t), wherein oj,k(t) represents the kth subband of the jth output channel signal and is constructed by combining components of the input signals L(t) and R(t) according to an output construction rule: oj,k(t)=f(Lk(t),Rk(t)) for k=1, 2, . . . , M and j=1, 2, . . . , N.

Abstract: A vehicle sound system is constructed and arranged to establish a sound image at a desired location spaced from the sound source.

Abstract: A system and method of producing an output sound field that is representative of an input sound field compatible with both existing prior art sound reproduction systems, for example ITU 5.1/6.1, and with a three-dimensional reproduction system unique to this disclosure. One embodiment of the disclosed system is comprised of a microphone array, an encoder, a decoder, and a plurality of speakers, some of which may not be located in the plane of the listener. A further embodiment discloses matrices to encode and decode the signals representative of the input and output sound fields respectively.

Abstract: A digital audio signal processing system and method transforms two-channel stereo time-domain data into the frequency domain. Vector operations are performed upon the frequency-domain data by which signal components unique to one of the input channels are routed to one of the output channels, signal components unique to the other of the input channels are routed to another of the output channels, and signal components common to both channels are routed to a third and optionally to a fourth output channel. The frequency-domain output channels are then transformed back into the time-domain, forming an equivalent number of channels of output audio data. The vector operations are performed in a manner that preserves the overall information content of the input data.

Abstract: Provided are an apparatus and a method for reproducing a surround wave field using wave field synthesis. The apparatus includes an audio signal analyzer for analyzing a received multi-channel audio signal to check the number of audio signal channels, and extracting a sound source signal for each checked channel from the multi-channel audio signal; a wave field synthesis renderer for localizing the extracted sound source signal for each channel at a virtual sound image outside a narrow space using wave field synthesis so that the extracted sound source signal is suitable for the number of the checked audio signal channels; and an audio reproducer for reproducing the localized virtual sound source signal.

Abstract: A technique for reducing inherent noise in a real time digital audio wireless system. The technique allows for low power stereo analog to digital and digital to analog converters to be used in a battery operated real time digital audio wireless applications. The audio signal is sent to the left and right channels of an analog to digital converter with a preceding audio amp of different gain at the input to each channel. The signals are simultaneously digitized then combined to generate a new digital value resulting in noise reduction at lower amplitudes. This new data word is then transmitted via radio waves to a digital audio receiver. Once the data is received it is output simultaneously to a stereo digital to analog converter. The digital to analog conversion of both left and right channels is then summed using a resistor network and an audio amplifier. The audio amplifier output is then reduced to create further reduction of noise at all amplitudes.

Abstract: An audio system for processing two channels of audio input to provide more than two output channels. The input may be conventional stereo material or compressed audio signal data. The audio processing includes separating the input signals into frequency bands and processing the frequency bands according to processes which may differ from band to band. The audio processing includes no processing of L?R signals.

Abstract: A stereo signal with enhanced perceptual quality using a mid-signal and a side-signal, can be generated, when a enhanced side signal is created prior to the upmix of the stereo signal. A decorrelated representation of at least a portion of the sum signal and/or a decorrelated representation of at least a portion of the side-signal is generated. The enhanced side-signal is generated combining a representation of the side-signal with the decorrelated representation of the portion of the mid signal, with the decorrelated representation of the side-signal and the decorrelated representation of the portion of the mid-signal or with the portion of the mid-signal and the decorrelated representation of the portion of the side-signal. The stereo signal with enhanced perceptual quality is created using a representation of the mid-signal and the enhanced side-signal.

Abstract: Aspects of the invention provide methods, computer-readable media, and apparatuses for digital processing of acoustic signals to create a reproduction of a natural or an artificial spatial sound environment. An aspect of the invention supports spatial audio processing such as extracting a center channel in up-mixing stereo sound for multi-channel loudspeaker setup or headphone virtualization. An aspect of the invention also supports directional listening in which sound sources in a desired direction may be amplified or attenuated. Direction and diffuseness parameters for regions of input channels are determined and an extracted channel is extracted from the input channels according to the direction and diffuseness parameters. A gain estimate is estimated for each signal component being fed into the extracted channel and an extracted channel may be synthesized from a base signal and the gain estimate. The input channels may be partitioned into a plurality of time-frequency regions.

Abstract: An audio system for processing two channels of audio input to provide more than two output channels. The input may be conventional stereo material or compressed audio signal data. The audio processing includes separating the input signals into frequency bands and processing the frequency bands according to processes which may differ from band to band. The audio processing includes no processing of L?R signals.

Abstract: A circuit for processing multichannel audio signals, comprises a frequency characteristics correction device and an output device. The frequency characteristics correction device corrects frequency characteristics of an audio signal of a channel including an audio signal component having a predetermined frequency band, of audio signals of a multichannel comprising at least a right channel and a left channel, in accordance with correction characteristics determined based on a head related transfer function. The output device mixes the audio signal component having the frequency characteristics corrected with an audio signal of the right channel and an audio signal of the left channel to generate mixed output audio signals, and outputting the mixed output audio signals as a right channel output audio signal and a left channel output audio signal.

Abstract: A sound processing system increases the robustness of surround sound in various playback situations. The system may process an incoming signal, such as a five channel surround sound signal, with a first and a second matrix. The first and second matrices produce outputs signals from the input incoming signals. At least one of the output signals may be combined before being sent to the speakers.

Abstract: Separating a source in a stereo signal having a left channel and a right channel includes transforming the signal into a short-time transform domain; classifying portions of the signals having similar panning coefficients; segregating a selected one of the classified portions of the signals corresponding to the source; and reconstructing the source from the selected portions of the signals.

Abstract: A method and an apparatus to reproduce a multi-channel audio signal, in which mixing of a center channel signal is performed with a center channel signal in a home theater system. The method of reproducing a multi-channel audio signal includes calculating a delay value of a center channel signal according to location relationships of a listener, a center channel speaker and other channel speakers, regulating a time delay of the center channel signal according to the calculated delay value, and mixing the time-delay regulated center channel signal with other channel signals.

Abstract: A plural-channel audio signal (e.g., a stereo audio) is processed to modify a gain (e.g., a volume level or loudness) of an estimated dialogue signal (e.g., dialogue spoken by actors in a movie) relative to other signals (e.g., reflected or reverberated sound). In some aspects, a controller is used to control master volume and dialogue volume. In some aspects, one or more graphical objects and/or user interface elements are used to indicate volume levels and other information.

Abstract: Separating a source in a stereo signal having a left channel and a right channel includes transforming the signal into a short-time transform domain; classifying portions of the signals having similar panning coefficients; segregating a selected one of the classified portions of the signals corresponding to the source; and reconstructing the source from the selected portions of the signals.

Abstract: High and low frequency components Cn1, Cn2 are generated by causing a center channel audio signal Cn to pass through a high-pass filter HPF and a low-pass filter LPF, and the high frequency component Cn1 is supplied to the center channel loudspeaker SPC. Also, two low frequency components Cn2L, Cn2R, which have a different phase mutually, are generated by causing the low frequency component Cn2 to pass through phase shifters 2, 3. An synthesized audio signal SL is generated by synthesizing the low frequency component Cn2L and the front-left channel audio signal FL, and then supplied to the front-left channel loudspeaker SPL. An synthesized audio signal SR is generated by synthesizing the low frequency component Cn2R and the front-right channel audio signal FR, and is supplied to the front-right channel loudspeaker SPR.

Abstract: A two-channel to three-channel audio converter that separates the lower frequency output signals from one of the left channel and the right channel is provided. Respective filters are used to separate the lower frequency outputs and the middle to high frequency outputs from the audio output signals of the computer device. An equalizer balances the powers of the left channel and the right channel outputs, so that the mismatches in the resistance may be avoided. A wireless receiver is integrated into the two-channel to three-channel audio converter to facilitate the multimedia applications.

Abstract: A two-channel to three-channel audio converter that separates the lower frequency output signals from one of the left channel and the right channel is provided. Respective filters are used to separate the lower frequency outputs and the middle to high frequency outputs from the audio output signals of the computer device. An equalizer balances the powers of the left channel and the right channel outputs, so that the mismatches in the resistance may be avoided.

Abstract: High and low frequency components Cn1, Cn2 are generated by causing a center channel audio signal Cn to pass through a high-pass filter HPF and a low-pass filter LPF, and the high frequency component Cn1 is supplied to the center channel loudspeaker SPC. Also, two low frequency components Cn2L, Cn2R, which have a different phase mutually, are generated by causing the low frequency component Cn2 to pass through phase shifters 2, 3. An synthesized audio signal SL is generated by synthesizing the low frequency component Cn2L and the front-left channel audio signal FL, and then supplied to the front-left channel loudspeaker SPL. An synthesized audio signal SR is generated by synthesizing the low frequency component Cn2R and the front-right channel audio signal FR, and is supplied to the front-right channel loudspeaker SPR.

Abstract: In an audio apparatus 10 to which plural kinds of audio signals of different numbers of channels are input, a sound field control section 3 which performs a sound field control on the audio signals on the basis of a sound field control data is provided, and the sound field control data is stored in a memory 6 for each of the kinds of audio signals.

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.

Abstract: A motion picture soundtrack reproduction system has a center front soundtrack channel and a plurality of other soundtrack channels. A volume control adjusts the gain of all the channels. The volume control has a range of settings from a minimum to a maximum, the gain of the center front channel having substantially a first relationship to the volume control settings and the gain of the other channels having substantially a second relationship to the volume control settings, the relationships being such that for a range of volume control settings less than a first setting the gain of the center front channel remains substantially constant while the gain of the other channels decreases as the setting decreases or decreases more gradually than the gain of the other channels as the setting decreases.

Abstract: An apparatus and method of generating multi-channel audio signals includes a voice signal removal unit to generate a first signal by removing one or more components of a plurality of frequency bands corresponding to a voice frequency range from an input signal, a voice signal amplification unit to generate a second signal by calculating a sum of channel signals of the input signal and amplifying one or more components of the plurality of the frequency bands corresponding to the voice frequency range of the sum signal, a control filter to generate a third signal by compensating for a level of the first signal, and a multi-channel audio generation unit to generate a center-channel audio signal and a front-channel audio signal using the second, third, and fourth signals.

Abstract: In a loudspeaker system with main and sub-speakers, a modified and inverted left surround signal is added to the signals driving the right main speaker and a modified and inverted right surround signal is added to the signals driving the Left Main Speaker for the purpose of creating more credible rear located phantom sound images. In a system using variations of a difference signal to create phantom rear located sound images, the components of the difference signal are modified by introducing a time delay to one of the components for the purpose of preventing the components of the difference signal from substantially canceling each other. The components of the difference signal may be modified by altering the relative level and frequency response of the components for the purpose of preventing the components of the difference signal from substantially canceling each other.

Abstract: A multichannel audio format provides a truly discrete as well as a backward compatible mix for surround-sound, front or other discrete audio channels in cinema, home theater, or music environments. The additional discrete audio signals are mixed with the existing discrete audio channels into a predetermined format such as the 5.1 audio format. In addition these additional discrete audio channels are encoded and appended to the predetermined format as extension bits in the bitstream. The existing base of multichannel decoders can be used in combination with a mix decoder to reproduce truly discrete N.1 multichannel audio.

Abstract: A sound processing system reduces the instances when only a center speaker is heard. The gain of a volume setting is adjusted for individual speakers in response to one or more input signals. The gain of the center speaker is attenuated in relation to the global volume setting. In addition or as an alternative, the gain of front and/or rear speakers is increased. A virtual center channel is generated for locations where the center speaker may not be heard.

Abstract: The present invention uses multivoice coil drivers in conjunction with the small satellite speakers of multichannel surround sound systems to achieve an overall linear response between 100 Hz to above 15 KHz. The multivoice coil drivers are designed to respond only to frequencies that fall between conventional upper base and lower midrange crossover frequencies which typically extend between 75 Hz and 225 Hz. The invention relies on the characteristics of human hearing which limits the listener's ability to localize the source of sound approximately to the wavelength of the sound being heard. The system may be incorporated in existing front and rear center speakers or separate enclosures to supplement the overall surround sound system.

Abstract: A central speaker and personal headset speakers are used to create a three-dimensional phantom sound space for each listener. The speakers of the headset are located in close proximity to, but do not isolate, the ears of the listener such that external sounds are allowed to impinge upon the pinna of the ears. The headset speakers form an isosceles triangle with the distant central speaker as the apex. This speaker configuration with personal controls can achieve a state of sound equilibrium for a phantom three-dimensional sound space. The sound signal may be synchronized with a video signal, and the sound pressure level of the left and right speakers can be adjusted to control the listener's perception of the virtual movement of phantom sound source image within the sound space according to changes in the point of view represented in a displayed video image.

Abstract: The present invention was developed in order to realize a multi-channel sound system wherein appropriate output (balance and fader) control can be conducted without adversely affecting the program contents, and a sound system, which can reproduce a plurality of channel signals including at least left and right front channels and a center channel for forward-placed speakers, comprises a gain controller to control the gain of either left or right channel signal and a gain controller to control the gain of the center channel signal depending on the gain control of the left or right channel signal.

Abstract: A three-dimensional sound reproducing apparatus is configured by cascading a sound field effect adding unit and a crosstalk canceling unit. The sound field effect adding unit adds a predetermined three-dimensional sound field effect to an input audio signal, thereby generating audio signals respectively corresponding to left and right channels. The crosstalk canceling unit performs a calculation process on the audio signals of the two channels so that, when the audio signals are respectively generated by two loudspeakers positioned in front of a listener, the audio signals reach the left and right ears of the listener without producing crosstalk. The resulting audio signals are supplied to the loudspeakers, respectively.

Abstract: The inventive mechanism uses several sub-systems to generate outputs from the stereo input signal. A first sub-system synthesizes the phantom center output, which places the monaural center image between the left and right speakers in front of the listener. A second sub-system synthesizes the virtual surround (or rear) output signals, which places the sound images to the sides of the listener. A third sub-system synthesizes the left and right stereo outputs, and expands the locations of the left and right sound images.

Abstract: A surround sound reproduction system uses a series of filters and a system of main and sub-speakers to produce phantom rear surround sound channels or a phantom surround sound effect from a loudspeaker system or pair of loudspeaker systems located in front of the listener. The sound system includes left and right surround input signals, and left and right front input signals. Left and right sub-speakers, and left and right main speakers are located in front of a listening location. Spacing between respective main and sub-speakers is approximately equal to ear spacing for an average person. The input to the left sub-speaker comprises the right surround signal subtracted from the left surround signal each signal having previously passed through a front-to-back filter and a series of high and low pass filters. The input into the left main speaker comprises the left front signal added to the left surround signal after the left surround signal has passed through a front-to-back filter.

Abstract: A multi-dimensional audio processor receives as an input either a single channel signal or a two channel signal from an audio signal source; for example a musical instrument or an audio mixer. The processor is programmable to divide the input among at least 3 output channels in a user-defined manner. The processor is also user programmable to provide a variety of effect and mixing functions for the output channel signals.

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.

Abstract: A pair of matched monaural speakers are added inside conventional left and right stereo speaker housings so that the left, right and flat panel monitor appear joined in a seamless aesthetic effect. The added speakers are provided with center channel monaural sound, making it appear as though such sound emanates from the center of the monitor, thereby enhancing home theater impact to provide stereo and center channel sound from each left and right speaker housing.

Abstract: An audio reproducing device includes an input for receiving an n-channel input signal, an output for supplying an 1-channel output signal to 1 loudspeakers, and an audio processing unit for processing the input signal. The audio processing unit a signal enhancer for enhancing an m-channel signal part of the n-channel input signal, where m<n, the signal enhancer having, for each channel signal part of said m-channel signal part, a non-linear anti-symmetric monotone transfer function. The audio reproducing device is further provided with a speech-music discriminator, which, in response to one of the channel signal parts of the m-channel signal part designated for speech, generates a control signal indicating the probability p that the one of the channel signal parts contains speech signals. This control signal is used to control the signal enhancer.

Abstract: Method and related apparatus for canceling vocal portions containing in two signals of two stereo channels and providing two corresponding output signals. The method includes: generating a mono signal according to a sum of the signals of the stereo channels; respectively performing vocal cancellation to each signal of one stereo channel according to a difference between the signal of the stereo channel and the mono signal, and performing low-frequency band and high-frequency band compensation to results of vocal cancellation to generate the two output signals. Because vocal cancellation is performed for respective signal of one stereo channel, the two output signals will have substantial difference in frequency band other than the high-frequency band to increase effect of stereo.