Abstract: A system and a method for correcting, simultaneously at multiple-listener positions, distortions introduced by the acoustical characteristics includes warping room responses, intelligently weighing the warped room acoustical responses to form a weighted response, a low order spectral fitting to the weighted response, forming a warped filter from the low order spectral fit, and unwarping the warped filter to form the room acoustical correction filter.

Abstract: According to some embodiments, a first audio stream associated with a first image stream and a second audio stream associated with a second image are determined. The first and second audio streams may each have, for example, at least two channels. The first and second audio streams may then be provided to an audio device as a single input stream, the audio device being adapted to receive a single audio input stream having at least four channels.

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 sound system (30) for a portable electronic device (20) is provided. The sound system includes a sound generator (28), a sound processor (25), and a speaker subsystem (24). The sound generator is configured for generating sound recordings with single sound format. The sound processor electronically connects with the sound generator and is configured for receiving the sound recordings with single sound format transmitted from the sound processor. The sound processor is configured for processing the sound recordings with single sound format into sound recordings with 5.1 surround format. The speaker subsystem electronically connects with the sound processor and is configured for receiving the sound recordings with 5.1 surround format transmitted from the sound processor and playing the sound recordings with 5.1 surround format.

Abstract: A system for 3D sound processing. The system includes a first processing section including a first left lattice filter and a first right lattice filter, respectively electrically connected to a second left lattice filter and a second right lattice filter, and including two negative couplers, each electrically connected to the first left and right lattice filters and also electrically connected to the second left and right lattice filters, and a second processing section including a left filter and a right filter, respectively electrically connected to the second left lattice filter and the second right lattice filter.

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: The invention generally relates to a method and apparatus for taking an input signal, replicating it a number of times and modifying each of the replicas before routing them to respective output transducers such that a desired sound field is created. This sound field may comprise a directed beam, focussed beam or a simulated origin. In a first aspect, delays are added to sound channels to remove the effects of different travelling distances. In a second aspect, a delay is added to a video signal to account for the delays added to the sound channels. In a third aspect, different window functions are applied to each channel to give improved flexibility of use. In a fourth aspect, a smaller extent of transducers is used top output high frequencies than are used to output low frequencies. An array having a larger density of transducers near the centre is also provided. In a fifth aspect, a line of elongate transducers is provided to give good directivity in a plane.

Abstract: A distributing circuit distributes audio signals of a predetermined number of channels to audio signals of a predetermined number of channels. A first signal processing circuit processes audio signals that are output from the distributing circuit in parallel, reproduces the resultant signals with a plurality of speakers, and localizes sound images of the individual audio signals at predetermined positions. A second signal processing circuit inputs audio signals that are output to the plurality of speakers and performs signal processes equivalent to the transfer functions from the individual speakers to both the ears of the listener. The output signals of the second signal processing circuit are reproduced with the headsets.

Abstract: The beginning detection, accommodation and frequency bias properties of the human hearing mechanism have been modeled to create systems that can detect directional transients (“sound events”) in a sound field and localize them. These systems break down a sound field into sound events and non-sound events and separately localize the sound events and non-sound events. Sound events are generally identified according to the frequency bias and beginning detection properties. Once detected, the sound events are generally localized according to differential steering angles (steering angles to which the steady-state signals have been accommodated) or ordinary steering angles, both of which reflect the direction of a sound event indicated during the rise-time of the sound event. When no sound events are detected, non-sound events are localized according to a steering angle that does not reflect rapid motion.

Abstract: The beginning detection, accommodation and frequency bias properties of the human hearing mechanism have been modeled to create systems that can detect directional transients (“sound events”) in a sound field and localize them. These systems break down a sound field into sound events and non-sound events and separately localize the sound events and non-sound events. Sound events are generally identified according to the frequency bias and beginning detection properties. Once detected, the sound events are generally localized according to differential steering angles (steering angles to which the steady-state signals have been accommodated) or ordinary steering angles, both of which reflect the direction of a sound event indicated during the rise-time of the sound event. When no sound events are detected, non-sound events are localized according to a steering angle that does not reflect rapid motion.

Abstract: An audio enhancement system and method for use receives a group of multi-channel audio signals and provides a simulated surround sound environment through playback of only two output signals. The multi-channel audio signals comprise a pair of front signals intended for playback from a forward sound stage and a pair of rear signals intended for playback from a rear sound stage. The front and rear signals are modified in pairs by separating an ambient component of each pair of signals from a direct component and processing at least some of the components with a head-related transfer function. Processing of the individual audio signal components is determined by an intended playback position of the corresponding original audio signals. The individual audio signal components are then selectively combined with the original audio signals to form two enhanced output signals for generating a surround sound experience upon playback.

Abstract: To date, there has been no speaker-characteristic compensation method including a processing step of reducing crosstalk between speakers incorporated in a mobile terminal. Accordingly, it has been impossible to reduce crosstalk that, in a mobile terminal, occurs between speakers. A speaker-characteristic compensation method, for a mobile terminal device having at least two speakers in a case, according to the present invention includes steps of reducing mutual crosstalk between the speakers, thereby reducing crosstalk between the speakers.

Abstract: An apparatus for processing a media signal and method thereof are disclosed, by which the media signal can be converted to a surround signal by using spatial information of the media signal. The present invention provides a method of processing a signal, the method comprising of generating rendering information by using spatial information indicating features between multi-sources and filter information having a surround effect; and generating a surround signal by applying the rendering information to a downmix signal generated by downmixing the multi-sources, wherein a tab number of a filter used in applying the rendering information to generate the surround signal is variable.

Abstract: A data processing apparatus is designed for simulating an acoustic characteristic of an acoustic space which contains a sound source for generating a sound and a sound receiving point for receiving the sound. In the apparatus, each of a plurality of characteristic control sections processes sound data and outputs the processed sound data. The characteristic control sections correspond to transmission paths which must exist in the acoustic space such that the sound generated from the sound source travels to the sound receiving point through the respective transmission paths. An instruction section provides a processing instruction of the sound data to each characteristic control section such that each characteristic control section processes the sound data according to the provided processing instruction to thereby execute the simulation of the sound traveling through the corresponding transmission path.

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: Input digital sound signals are subjected to filtering for convolution of respective impulse responses, and the resulting signals are supplied to time delay setting circuits. In each of the time delay setting circuits, output signals from two adjacent stages of the time delay setting circuits, which correspond to a direction closest to a detected facing direction of a listener, are taken out as two pairs of signals. In crossfade processing circuits, the signals in each pair are added at a proportion depending on the detected facing direction of the listener. Output signals of the crossfade processing circuits are taken out through correction filters for compensating frequency characteristic changes in a high frequency range. As a result, when listening to sound with headphones and localizing a sound image at an arbitrary fixed position outside the listener's head, noises generated upon a change in the facing direction of the listener are reduced.

Abstract: Provided are sound field reproducing apparatus and method. The sound field reproducing apparatus includes an input unit for receiving reflection reproducing information, a signal processor for selecting loudspeakers and calculating reflection signal for applying a panning algorithm based on the reflection reproducing information, a signal treatment unit for localizing the calculated reflection signal on a virtual sound image according to the panning algorithm; and a reproducer for reproducing the localized reflection signals through the selected loudspeakers.

Abstract: The invention relates to a method, signal processing device and computer program for stereo widening (SW) of stereo format signals to become suitable for headphone listening. The invention also relates to a mobile appliance performing signal processing according to the invention. According to the invention a separate monophonic signal path (ME) is formed in order to equalize the frequency spectrum of the monophonic component of the left and right output signals (Lout,Rout) by at least extracting from the left and right input signals (Lin,Rin) an at least substantially monophonic signal component contained in said signals (Lin,Rin), processing the extracted monophonic signal component to obtain a processed monophonic signal component, and combining said processed monophonic signal component with at least one of the left (Lout) or the right (Rout) output signals.

Abstract: A subwoofer (72) is equipped with a wireless receiver (80) to receive signals containing information for a Low Frequency Effects (LFE) channel and information for both surround channels. In one form, the LFE is added to one or both surround channels to provide a stereo surround signal (containing both surround channels including a multiplexed LFE channel). The subwoofer (72) utilizes the LFE channel, powers surround speakers (74, 76), and passes the surround signals to respective surround speakers. A receiver (66) multiplexes LFE signals into either one or both surround sound audio channels. A digital RF transmitter (70) of the receiver transmits the combined subwoofer/surround channels to the wireless receiver (80) of the subwoofer. The remote subwoofer is connected to a power source (78). The surround speakers (74, 76) are connected to the subwoofer so as to receive the surround channels and be powered thereby.

Abstract: Apparatus and method for transmitting and reproducing stereophonic audio signals are disclosed. The method comprises splitting first and second channels into two frequency bands, combining the lower frequency band signals of the two channels, and transmitting the combined signals of the two channels or signals representative thereof. The apparatus comprises: a splitter for splitting each of the two channels into two frequency bands, a combiner, for combining the lower frequency band signals of the two channels, and a transmitter for transmitting the combined signals, or signals representative thereof, and the higher frequency band signals of the two channels, or signals representative thereof.

Abstract: An audio apparatus includes an input unit for inputting stereo signals in which multi-channel surround-sound signals are mixed in accordance with a predetermined algorithm and a parameter indicating encoded contents of the algorithm, a surround-sound signal generator for generating left-side surround-sound signals and right-side surround-sound signals by decorrelating left-side signals and right-side signals contained in the stereo signals, and a controller for controlling the decorrelation performed by the surround-sound signal generator based on the parameter.

Abstract: An audio signal processing method that performs virtual acoustic image localization processing for sound source signals having at least one type of information among position information, movement information, and localization information based on this information there are a plurality of changes in this information within a prescribed time unit, a single information change is generated based on this plurality of information changes, and virtual acoustic image localization processing is performed for the sound source signals based on this generated information change.

Abstract: Signal processing apparatus produces an audio signal suitable for conveying a psychoacoustic perception of a low frequency audio signal to a listener, the apparatus generates harmonics of the low frequency signal by shaping the waveform of the low frequency signal with respect to time and/or level. This may be achieved using a peak-hold generator and a rectifier, or using a peak-hold-decay generator.

Abstract: The present invention provides an apparatus and a method for emulating audio. The apparatus comprises an echo device, a reverberation device, an audio source device and a first signal synthesizer. Wherein, the echo device receives an audio source signals and applies thereof for generating echo signal and feedback signal; the reverberation device receives the audio source signal and applies thereof in accordance with the feedback signal of the echo device for generating a reverberation signal; the audio source device receives the audio source signal and applies thereof for outputting a direct audio source signal; and the first signal synthesizer is used to receive and synthesize the echo signal, the reverberation signal and the direct audio source signal so as to output a first synthesized signal, which is an audio effect emulation signal.

Abstract: A system and method for enhancing the stereo sound effect produced by speaker systems having two or more speakers fed by two or more channels or audio, respectively. Second-order high pass filtering is applied to first and second audio signals of a stereo signal. A phase shift of approximately 180 degrees is applied to the resulting signals. A mixer mixes the processed first audio signal with the original second audio signal and mixes the processed second audio signal with the original first audio signal, whereby an expanded stereo sound field effect is created.

Abstract: The apparatus for constructing a multi-channel output signal using an input signal and parametric side information, the input signal including the first input channel and the second input channel derived from an original multi-channel signal, and the parametric side information describing interrelations between channels of the multi-channel original signal uses base channels for synthesizing first and second output channels on one side of an assumed listener position, which are different from each other. The base channels are different from each other because of a coherence measure. Coherence between the base channels (for example the left and the left surround reconstructed channel) is reduced by calculating a base channel for one of those channels by a combination of the input channels, the combination being determined by the coherence measure. Thus, a high subjective quality of the reconstruction can be obtained because of an approximated original front/back coherence.

Abstract: Said method for control of a reproduction unit (2) for an acoustic field with a number of reproduction elements (31 to 3N) is characterised in comprising: a step for establishing a finite number of coefficients representative of the temporal distribution and in the three spatial dimensions of said acoustic field, a step for determination of representative reconstruction filters for said reproduction unit (2) and at least the spatial configuration of said reproduction unit (2); a step for determination of at least on control signal (SC1 to SCN) for said elements (31 to 3N) by the application of said coefficients to said reconstruction filters and a step for providing said at least one control signal for application to said elements (31 to 3N) for generation of said acoustic field for reproduction.

Abstract: Sound processing systems have been developed that create a surround effect without quality degradation experienced by known sound processing systems in non-optimum listening environments. The sound processing systems may include matrix decoding systems that manipulate input signals prior to converting them into a number of output signals so that the output signals are a function of a greater number of input signals. These sound processing systems may also or alternately include a bass management system that from the input signals preserves the low frequency components of the input signals in separate channels. Both the matrix decoding systems and bass management systems may also produce additional signals. Further, the matrix decoding and bass management systems may be implemented separately or jointly in vehicular sound systems.

Abstract: An apparatus for generating a multi-channel output signal performs a center channel cancellation to obtain improved base channels for reconstructing left-side output channels or right-side output channels. In particular, the apparatus includes a cancellation channel calculator for calculating a cancellation channel using information related to the original center channel available at the decoder. The device furthermore includes a combiner for combining a transmission channel with the cancellation channel. Finally, the apparatus includes a reconstructor for generating the multi-channel output signal. Due to the center channel cancellation, the channel reconstructor not only uses a different base channel for reconstructing the center channel but also uses base channels different from the transmission channels for reconstructing left and right output channels which have a reduced or even completely cancelled influence of the original center channel.

Abstract: The present invention provides an audio information transforming device, an audio information transforming method, and an audio information transforming program, which are capable changing a listening point freely only by one audio stream and also achieving multiple channels only by the 1-channel audio information. In the provided method, a virtual listening point 105 is decided, and then an allocation ratio of the audio to a plurality of loudspeakers is changed based on a ratio of a distance between the virtual listening point 105 and an object 103 and a distance between the object 103 and a basic listening point 102. Accordingly, a large number of audio environments can be produced by changing information of the virtual listening point 105 based on one audio information.

Abstract: A sound reproduction system has been developed, for converting signals on two input channels into surround signals on five or seven output channels and vice-versa. A decoder is included in the sound reproduction system which enhances the correlated component of the input signals in the desired direction and reduces the strength of such signals in channels not associated with the encoded direction, while preserving the apparent loudness of all output channels, the separation between the respective left and right output channels and the total energy of the uncorrelated component of the input channels in each output channel. The decoder may include a uniquely defined matrix that helps to ensure that the surface of the output signals is smooth and continuous.

Abstract: A sound reproduction system comprises a left and right speakers located in close proximity, and a sound processor which provides audio signals to the pair of speakers. The sound processor preferably derives a cancellation signal from the difference between the left and right channels. The resulting difference signal is scaled, delayed (if necessary), and spectrally modified before being added to the left channel and, in opposite polarity, to the right channel. The spectral modification to the difference channel preferably takes the form of a low-frequency boost over a specified frequency range, in order to restore the correct timbral balance after the differencing process. Additional phase-compensating all-pass networks may be inserted in the difference channel to correct for any extra phase shift contributed by the spectral modifying circuit. The technique may be used in a surround sound system.

Abstract: A multi-channel audio reproduction apparatus and method for loudspeaker reproduction using virtual sound images whose positions can be adjusted is provided. The multi-channel audio reproduction apparatus includes a virtual sound image forming unit for compensating for the occurrence of cross-talk in at least one input audio signal according to the arrangement of loudspeakers, obtaining transfer functions occurring when sound from a position in a three dimensional space is transmitted to both ears of a listener, and forming a plurality of first virtual sound images in a three dimensional space using the transfer functions. A controller generates adjusting factors for adjusting the position of at least one second virtual sound image.

Abstract: An acoustic virtual environment is processed in an electronic device. The acoustic virtual environment comprises at least one sound source (300). In order to model the manner in which the sound is directed, a direction dependent filtering arrangement (306, 307, 308, 309) is attached to the sound source, whereby the effect of the filtering arrangement on the sound depends on predetermined parameters. The directivity can depend on the frequency of the sound.

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.

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: The present invention relates to audio visual devices, and is aimed to provide an audio box with stereo surround effect; an integrated multi-channel audio box having simple structure and neat appearances, no complex wiring necessary to connect to the source. The structure of the audio box is in rectangular shape. There are three or more than three independent audio channels, including at least one base channel. The present invention adopts one audio box instead of the current stereo system structure with many audio boxes; three or more than three independent channels are integrated into one rectangular audio box, the wiring connection between the audio boxes and source is greatly simplified. Only one cable is necessary to carry out the communication among all channels, or wireless connection can be adopted.

Abstract: There is provided a multichannel audio amplification apparatus including a speaker detection circuit for detecting whether or not a speaker is connected to an arbitrary speaker terminal of speaker terminal groups TA and TB, and an operating circuit and a display circuit connected to a control circuit. Even in a case where one of two speaker groups of A and B types connected to the multichannel audio amplification apparatus cannot be connected with a surround speaker for reproducing only a surround sound, a listener is prevented, by indication, from carrying out on the operating circuit an erroneous operation or setting which otherwise might be liable to occur both in a case where the B-type speaker group including no surround speaker is connected to the multichannel audio amplification apparatus and in a case where the B-type speaker group is not connected thereto.

Abstract: An acoustic image localization processing device that can localize an acoustic image of reproduced sound in an arbitrary position according to the circumstances of reproduction. To accomplish this, an acoustic image localization processing device includes a decoder that reproduces reproduction acoustic signals and angle selection signals SA from a DVD disc; angle selection specification signals that specify modification of the acoustic image position with respect to an angle selection signal; a synthesis circuit that performs processing to modify the acoustic image localization position of reproduced acoustic signals by using the angle selection signal, modified by the angle selection specification signal; and speakers that output reproduced sound, with the acoustic image localized in the modified acoustic image localization position.

Abstract: A method and system accept left and right channel inputs of audio data and provide output audio data for at least three channels in a fashion that may effect a facsimile of the original soundstage on which the left and right inputs were recorded.

Abstract: The invention provides transducer arrays which are capable of outputting sound beams having a relatively constant width, and with minimal sidelobes, across a range of frequencies. This is achieved by utilising one or more digital signal modifiers within the signal path between the input sound signal and the array of transducers. Variable window functions are also disclosed.

Abstract: Systems and techniques for controlling a surround sound system having multiple input signals and multiple spatially diverse transducers may include defining a first control region and a second control region. When operating in the first control region, a first set of functions is performed. For example, for each of the spatially diverse transducers, an input signal may be selected, a relative strength of the selected input signal may be adjusted, and the adjusted input signal may be applied to the transducer. When operating in the second control region, a second set of functions is performed. For example, for each of the spatially diverse transducers, two or more input signals may be selected, a relative strength of the selected input signals may be adjusted, the adjusted input signals may be mixed, and the mixed input signals may be applied to the transducer.

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: This invention addresses sound recording and mixing methods for 3-D audio rendering of multiple sound sources over headphones or loudspeaker playback systems. Economical techniques are provided, whereby directional panning and mixing of sounds are performed in a multi-channel encoding format which preserves interaural time difference information and does not contain head-related spectral information. Decoders are provided for converting the multi-channel encoded signal into signals for playback over headphones or various loudspeaker arrangements. These decoders ensure faithful reproduction of directional auditory information at the eardrums of the listener and can be adapted to the number and geometrical layout of the loudspeakers and the individual characteristics of the listener. A particular multi-channel encoding format is disclosed, which, in addition to the above advantages, is associated with a practical microphone technique for producing 3-D audio recordings compliant with the decoders described.

Abstract: An automotive in-cabin audio system comprising a plurality of speakers installed at different positions in the cabin is disclosed, in which the playback signal from a multichannel player having sources of at least three channels recorded therein is processed in accordance with the position of a listener seated in the cabin thereby to reproduce a sound similar to the original sound at the position of the listener. The signal of the sound reproduced from a speaker far from each seat in the cabin is retrieved as a branch signal and delayed in accordance with the law of the first wave front. At the same time, the level of the particular signal is attenuated to produce a processed sound signal, which is added to the signal of the sound reproduced from the speaker near each seat. As a result, a sound similar to the original sound can be heard at any hearing position in the cabin.

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: An audio enhancement system and method for use receives a group of multi-channel audio signals and provides a simulated surround sound environment through playback of only two output signals. The multi-channel audio signals comprise a pair of front signals intended for playback from a forward sound stage and a pair of rear signals intended for playback from a rear sound stage. The front and rear signals are modified in pairs by separating an ambient component of each pair of signals from a direct component and processing at least some of the components with a head-related transfer function. Processing of the individual audio signal components is determined by an intended playback position of the corresponding original audio signals. The individual audio signal components are then selectively combined with the original audio signals to form two enhanced output signals for generating a surround sound experience upon playback.

Abstract: An audio “desktop” user-interface is provided in which services are represented by audio labels presented in an audio field through respective synthesized sound sources. A desired service is selected by identifying it through its sound source or audio label. A user can modify the layout of service-representing sound sources and preferably add and remove services.

Abstract: A sound processing system adaptively mixes active matrix decoding and passive matrix processing of incoming audio signals. Mixed output signals are generated with active matrix decoding where the audio signals are stereo. Mixed output signals are generated with passive matrix processing where the audio signals are monaural. The sound processing system reduces the degree of active matrix decoding in the mixed output signals where the incoming audio signals are stereo and monaural. The sound processing system also generates virtual stereo signals from incoming audio signals having monaural signals. Mixed output signals are generated of the virtual stereo signals using active matrix decoding.