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 separately localize them. These models 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, 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 and which reflect the direction of a sound event indicated in its rise-time. When no sound events are detected, non-sound events are localized according to a steering angle that does not reflect rapid motion.

Abstract: A car-borne sound system that reproduces a recorded multi-channel music source in the 5. 1 system or the like system into a natural sound environment in a room of an automobile. Conventionally, at a driver's seat or at a front passenger seat, a sound image of vocal sounds (singing voice) was locating deviated from the natural placement. The present sound system eliminates such unnatural sound image positioning. A front center signal and a front right and a front left signals, which include much of the vocal components, are added on to a rear right and a rear left signals so that rear speakers (106 and 107) also reproduce the vocal components. Thus the vocal sound image is placed and fixed in the central place to provide a natural listening environment.

Abstract: The data put to the digital filter operation and the data not put to the digital filter operation are synthesized together at a predetermined distribution ratio to form a stereophonic sound image. A digital filter operation is executed for forming a sound image in the vertical direction that reaches one ear being diffracted by the head, and a digital filter operation is executed for forming a sound image in the vertical direction in the other ear, thereby to form a stereophonic sound image in the vertical direction. Of the sound generated from one of the different sound systems, the sound reaching one ear is canceled and the only sound reaching the other ear is validated by generating a counterbalance sound component. Excess sound component is erased, the excess sound component being generated from the other sound system and being not desired for forming the stereophonic sound image.

Abstract: An audio signal processing apparatus includes an input unit to which at least an audio signal of a left channel, an audio signal of a right channel, and an audio signal of a center channel are supplied, a first output terminal unit for outputting the audio signal of the left channel, the audio signal of the right channel, and the audio signal of the center channel which are supplied to the input unit, a mixing unit for mixing the audio signal of the center channel to the audio signal of the left channel and mixing the audio signal of the center channel to the audio signal of the right channel to output the mixed signals as audio signals of two channels, and a second output terminal unit for outputting the audio signals of the two channels from the mixing unit.

Abstract: A method and an apparatus for producing multi-channel stereophonic sound by which output 5.1-channel sound is converted into 7.1-channel sound are provided. An encoded audio stream is received and decoded. The decoded audio stream is reproduced as sound through 5.1 channels. Outputs of left and right speakers of a TV set are also produced using signals of a left stereo channel, a right stereo channel, and a center channel of the 5.1 channels.

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 separately localize them. These models 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, 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 and which reflect the direction of a sound event indicated in its rise-time. 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 separately localize them. These models 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, 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 and which reflect the direction of a sound event indicated in its rise-time. When no sound events are detected, non-sound events are localized according to a steering angle that does not reflect rapid motion.

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: Sound Space Replication is a multichannel audio system optimization and management system. The replication begins by mapping and storing volumetric acoustic topological data of the primary (audio creation) venue's sound system in situ, associated with the completion of an audio program material. Prior to playback, the secondary (audio listening) venue's sound system is similarly mapped in situ. The secondary data is compared to the primary data, with discrepancies articulated as corrections data. The corrections data applied to the secondary audio system include wave shaping, phase, spatial repositioning, miss-configured and phantom channel replacement, etc. The secondary audio system sound space is thus optimized as directly referenced to the primary audio system sound space.

Abstract: A sound field effect control apparatus and and a sound field effect control method are provided, which are capable of enabling a listener to listen to reflected sounds close to initial reflected sounds generated in an actual acoustic space, by utilizing information reflecting the position of a sound source possessed by multichannel audio source signals. Sound field effects are applied to multichannel audio source signals that are input to a sound field effect control apparatus. The multichannel audio source signals cause sound generated from an imaginary sound source at a predetermined position to be heard by the listener when converted into sound and generated by a plurality of loudspeakers. Multichannel initial reflected sound signals corresponding to initial reflected sounds that will be heard by the listener when the sound is generated from said imaginary sound source at said predetermined position in a predetermined acoustic space, are generated from the multichannel audio source signals.

Abstract: A method for decoding an audio signal includes receiving a digital audio signal having a plurality of channels defined thereon, wherein one of the plurality of channels is a center channel and at least one of the other of said plurality of channels is a remaining audio channel; comparing the center channel with the at least one of the other of the plurality of channels to determine a ratio of the center channel to the other of the plurality of channels; and automatically adjusting the center channel and the at least one of the plurality of other channels when a predetermined value for the ratio is not met.

Abstract: A matrix surround decoding system comprises a DIR 10 detecting a sampling frequency FS included in a stereophonic source, and a microcomputer 12 determining the type of stereo source on the basis of the sampling frequency detected by the DIR 10, and outputting to a matrix surround decoder 11 a mode switching signal CL for switching the output mode of the matrix surround decoder 11 to a mode corresponding to the determined type of stereophonic source.

Abstract: A pseudo-stereo circuit is provided which processes an input monophonic signal into stereophic audio signals. A phase-shift circuit shifts a phase of the input monophonic signal by a phase shift amount that depends upon a frequency of the monophonic signal, to produce an output signal having a gain with respect to the input monophonic signal which is equal to or larger than a predetermined level over an entire frequency band thereof, and reaches a peak at a frequency at which the phase shift amount of the output signal with respect to the input monophonic signal assumes a value equal or closer to −&pgr;. A mixing circuit produces a first mixed signal by mixing a signal obtained by inverting a phase of the output signal of the phase-shift circuit with the input monophonic signal by a first mixing ratio, and produces a second mixed signal obtained by mixing the output signal of the phase-shift circuit with the input monophonic signal by a second mixing ratio.

Abstract: An improved method and apparatus for creating multi-channel (or binaural) signals from a B-format sound-field source is disclosed. The method allows the encoded spatial format (B-format) to be separated into multiple bands, with each band assigned a short-term direction factor, from which the higher-resolution multi-channel (or binaural) output signals may be determined. The direction factor is determined, for each filter band, based on the short-term statistics of the soundfield signals in those bands. Based on this direction factor, the speaker drive signals are computed for each band by panning the signals to drive the nearest speakers. In addition, residual signal components are apportioned to the speaker signals by means of previously known decoding techniques.

Abstract: A technique for enhancing audio signals generated from compressed digital audio files is described. The technique uses a Bass Maximizer module, a Harmonic Exciter module and a Quasi Stereo module. The Bass Exciter module enhances the intensity, depth and punch of the bass audio content by creating harmonic sequences from low frequency components contained in the original input signal. The Harmonic Exciter module adds to the treble audio content of the original input signal by generating harmonic series from the high frequency components contained in the input signal. The Quasi Stereo Module creates a stereo image of the enhanced input signal by adding and subtracting delayed and filtered versions of the enhanced input signal with itself to create left and right channeled stereo-like outputs. The technique provides a useful tool to regenerate from an audio signal more pleasant and joyful sounds.

Abstract: The invention relates to a method and an arrangement for recording and playing back sounds, especially music, whereby stereo recording and playback techniques are at least partially used. The aim of the invention is to allow for a three-dimensional acoustic reproduction, especially music reproduction, that comes as close to a natural experience as possible. According to the inventive method, the aim of the invention is achieved by at least one 2+2+2 recording and playback technique and by means of a corresponding number of sound tracks for producing a sound impression which is realistic, three-dimensional and closely resembling nature in width, depth and height.

Abstract: A sound enhancement system (synthesizer) disclosed. The enhancement system synthesizes pseudo-stereophonic left and right output channels output from a monophonic input channel. The monophonic input signal is applied to a perspective filter that produces a differential-mode signal and to an equalizer filter that produces a common-mode signal. The perspective filter attenuates signal components in a frequency range corresponding to the human voice. The equalizer filter attenuates signal components in a frequency range outside the frequency range of the human voice. The equalizer filter also provides a 90 degree phase shift. The differential-mode and the common-mode signals are combined to produce the output channels. The pseudo-stereo output provided by the synthesizer has relatively less ambience in the frequency range corresponding to the human voice and relatively more ambience in frequency ranges that do not correspond to the human voice.

Abstract: A method of synthesizing a three dimensional sound-field using a pair of front and a pair of rear loudspeakers, including: a) determining the desired position of a sound source; b) providing a binaural pair of signals corresponding to the sound source using an HRTF filter; c) providing the left signal of said binaural pair of signals to both the left front and left rear loudspeakers through a front and a rear gain control means respectively; d) providing the right signal of said binaural pair of signals to both the right front and right rear loudspeakers through a front and a rear gain control means respectively; e) controlling the ratio of the front signal gains to the rear signal gains as a function of the azimuth angle of the sound source; and f) performing transaural crosstalk cancellation on the front and rear signal pairs through respective transaural crosstalk cancellation means.

Abstract: The production of multidirectional or instantaneous live virtual surround sound broadcasting is obtained by positioning a plurality of microphones on an oval frame in a predetermined pattern and with a predetermined orientation, connecting the microphones to a virtual surround semiconductor chip and connecting outputs from the semiconductor chip to a pair of speakers.

Abstract: A background-sound control apparatus, a background-sound control method, readable recording medium containing a background-sound control program, and a video game apparatus improve effectiveness of background-sound data provided over a predetermined number of channels. When background sounds are produced through a speaker, a sound-level controller controls output ratios for sound levels defined in background-sound data on a channel basis and uses a sound-level control function to perform crossfading sound-level control.

Abstract: A stereo broadcasting receiving device comprises pseudo stereo signal generation means for generating a pseudo left stereo signal and a pseudo right stereo signal from an L+R signal, first multiplication means for multiplying the pseudo left stereo signal by a first coefficient, second multiplication means for multiplying the pseudo right stereo signal by the first coefficient, third multiplication means for multiplying the L+R signal by a second coefficient, fourth multiplication means for multiplying an L−R signal by a third coefficient, coefficient determination means for determining the first coefficient, the second coefficient, and the third coefficient on the basis of the result of judgment in receiving state judgment means, means for generating a left stereo output signal on the basis of an output signal of the first multiplication means, an output signal of the third multiplication means, and an output signal of the fourth multiplication means, and means for generating a right stereo o

Abstract: A multimedia computer speaker system includes a pair of amplifiers that provide amplified right and left audio signals to a pair of wide-band speakers. The amplifiers are configured to provide the amplified right and left audio signals that are out of phase with each other. The amplified right and left audio signals are applied to opposite terminals of the two wide-band speakers. These reversed terminal couplings to the wide-band speakers of the phase-reversed signals provide phase-aligned right and left audio playback at the speakers. A subwoofer and a low pass filter are connected as a bridge-tied load to receive the amplified right and left audio signals. The phase of one amplified audio signal is in effect reversed by applying it to the negative terminal of the subwoofer. As a result, low frequency components of a phase reversed amplified audio signal are summed by the subwoofer with low frequency components of the other amplified audio signal to provide a low frequency audio playback.

Abstract: This invention provides a system capable of transitioning from surround sound effect to stereo sound effect, and then to a monophonic sound effect using front speakers. A user may control the amount of surround sound effect that is combined with stereo sound effect, and the amount of stereo sound effect that is combined with monophonic sound effect. The user may also control the system to hear pure surround sound effect, stereo sound effect, or monophonic sound effect. The system may allow a user to control the contribution of a particular sound effect by controlling the relative proportions of the filtered dipole signals and the attenuated unfiltered dipole signals. The signal processing may be also done through an analog device. The system may also process some audio channels in an inverted form and compensate for these inversions by reversing the polarity of that output to the speaker, as well as accept two-channel and four-channel audio inputs.

Abstract: The present invention includes: a front L-channel speaker unit for outputting a front L-minus-R signal; a front R-channel speaker unit for outputting a front R-minus-L signal; a front center speaker unit for outputting a front center signal consisting of front R-plus-front L; a rear L-channel speaker unit for outputting a rear L-minus-R signal; a rear R-channel speaker unit for outputting a rear R-minus-L signal; and a rear center speaker unit for outputting a rear L-plus-R signal. The subtracted signals contain only frequency components below a predetermined frequency.

Abstract: A method and apparatus implements a novel surround sound panning paradigm. Rather than controlling the x-y position of a perceived sound source within a linear grid, the perceived sound is characterized by specifying perceived arrival energy as a function of direction of arrival. In one embodiment, perceived sound source azimuth and width (or spatial extent) are specified, which parameters are used in a novel panning law to control each output channel. In a preferred implementation, the panning control is provided in a Plug-In application for a conventional DAW environment such as Pro Tools, which application includes an interface that provides precise control over the direction and spatial extent of audio.

Abstract: An automotive audio reproducing apparatus according to the present invention comprises: a sound image position correction circuit 52 for converting a left-channel input digital audio signal XL(Z) and a right-channel input digital audio signal XR(Z) into a digital audio signal YL(Z) and a digital audio signal YR(Z), respectively, for output expressed by: YL(Z)·GLL(Z)+YR(Z)·GLR(Z)=XL(Z)·FLL(Z)+XR(Z)·FLR(Z) YR(Z)·GLL(Z)+YL(Z)·GLR(Z)=XR(Z)·FLL(Z)+XL(Z)·FLR(Z) where FLL(Z) to GLR(Z) are given head related transfer functions; a depth correction circuit 53 for adding reflected sound signals to the signals YL(Z) and YR(Z), respectively; a D/A converter circuit 6 for subjecting output signals of the correction circuit 53 to D/A conversion; and a level control circuit 522 for controlling level of a difference signal in the sound image position correction circuit 52; whereby analog audio signals outputted from the D/A converter

Abstract: An automatic LFE audio signal derivation processor incorporating signal measurement functions, signal filtering functions, signal limiting/compressing functions, signal gain adjusting functions, and operating indication functions, for use with multichannel soundtracks. Audio input signals are fed to the processor and split for processing in three blocks, including a detector, which analyzes the low frequency content of the incoming signal and controls each of two subsequent blocks, a variable low frequency shelving network in which the amount of low frequency attenuation is variable and which responds to a control signal from the detector, and a variable gain amplifier in which the gain responds to the control signal from the detector circuit.

Abstract: A multi-channel stereo converter is described comprising stereo magnitude determining means for generating a stereo information signal (a/b; &rgr;), which represents a degree of stereo between audio input signals (L, R), and transforming means for transforming said audio signals (L, R) based on said stereo information signal (a/b; &rgr;) into at least a surround signal (S). A space mapping interpretation is presented and an audio center signal may be derived from the stereo input signals as well. The result is more flexibility in application and design, without substantial cross talk in the audio signals.

Abstract: A surround sound field reproduction system and method is disclosed by which, in such a case that a listener changes its posture so that a portion of a video image to which attention should be paid may be observed in front of the listener, a sound image can be localized accordingly in a direction in which the video image is observed in front of the listener. Specifically, the surround sound field reproduction apparatus includes a plurality of horizontal panners for receiving a plurality of sound signals from microphones disposed horizontally and cooperating with each other to control the horizontal localization, and a vertical panner for receiving sound signals from microphones disposed vertically to control the vertical localization. The horizontal panners level-distribute the received sound signals to a plurality of output channels provided corresponding to surround reproduction output channels.

Abstract: There are provided a plurality of filter units provided in corresponding relation to a plurality of predetermined directions on a one-to-one basis, and each of the filter units processes an input tone signal with predetermined transfer characteristics peculiar to the predetermined direction corresponding thereto. Each of the filter units processes the tone signal with transfer characteristics for simulating transfer of a sound from the corresponding predetermined direction to left and right ears of a human listener, and thereby outputs processed tone signals corresponding to the left and right ears. Namely, sound image localization is achieved by synthesis of sound components arriving from a plurality of different predetermined directions. Variation of the sound image localization can be controlled by controlling respective levels of input signals to the individual filter units.

Abstract: A device and a method for reproducing a multi-channel audio signal with only two speakers preserving the sound field of multi-channel audio reproduction, thereby providing vivid realism to a user (listener).

Abstract: An audio user interface is provided in which items are represented in an audio field by corresponding synthesized sound sources from where sounds related to the items appear to emanate. The sound sources are located in the audio field relative to an audio field reference. In order to rotate the audio field either in response to user input or to achieve a particular stabilisation of the audio field, the audio-field reference can be offset relative to presentation reference determined by a mounting configuration of audio output devices through which the sound sources are synthesised. To assist the user in appreciating the current orientation of the audio field, a visual indication is given of the orientation of the audio-field reference relative to a predetermined indicator reference taking account, at least at a component level, of any change in value of said offset and any change in value of indicator-reference orientation relative to the presentation reference.

Abstract: An audio mixer system is described for producing coded output in which at least a left audio signal, a right audio signal and a surround audio signal are encoded in two output channels so that the surround signal can be decoded from the difference of the two output channels. The system comprises means for generating position data designating a desired position for a sound source in a 360 degree sound field. Logic is provided for determining the relative volume of the sound source in the left, right and surround audio signals from the position data. A signed continuity factor is maintained so that the sign of the continuity factor is changed in response the desired position crossing a nominal position of the surround signal in the sound field and logic is provided for encoding the sound source data into the two output channels in accordance with the determined relative volume of the sound source in at least two of the left, right and surround signals each multiplied by the continuity factor.

Abstract: An artificial stereophonic circuit which includes a monophonic signal input terminal, a signal output terminal of one of an L channel and an R channel which are connected to the signal input terminal, a phase-shifting circuit having an input side connected to the signal input terminal, and a signal output terminal of the other channel of the L channel and the R channel having an output side connected to the phase-shifting circuit. The phase-shifting circuit has an almost equal gain in a full frequency band of an input signal, and a phase shift for a change from 0 to 180 degrees according to an increase in a frequency of the input signal is carried out. The change of the phase can be minimized and a natural stereophonic effect can be realized. Moreover, only one capacitor is enough and only one pin for external attachment is enough for wholly forming an IC.

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.

Abstract: The present invention is to provide a system and method for setting various acoustic and visual parameters for optimal or intended reproduction of digital multi-channel surround encoded audio and for optimal or intended reproduction of a visual image from a display device in a home theater system. For example, one feature of the present invention is to incorporate a hand-held remote control device which operates the main surround sound unit (e.g., home theater receiver and/or digital decoder) and the display device via electromagnetic link, for example. Of course, it is not necessary to the invention that the device be incorporated in the remote control device of the surround sound unit, or the display device.

Abstract: A method and audio converter for generating further audio signals (u, ul, ur, uc, us) from initial audio signal (x, xl, xr), wherein optionally an information signal (in means 23) is derived from said initial audio signals (x). On basis of the initial audio signal (x, xr, xl), a dominant signal y(k) and a residue signal (or signals) q(k), substantially transverse to each other, are determined (means 21 and 22). In at least two frequency ranges frequency components of the dominant signal are analysed (means 24), and a difference signal yr ({y(k)−yb(k)) corresponding to the dominant signal minus a frequency range component of the dominant signal in one or more frequency ranges (yb(k)) is formed. The difference audio signal yr and the residue signal q(k) are transformed into said further audio signal u (means 25), i.e. 1 u = T ⁡ ( y r ⁡ ( k ) q ⁡ ( k ) ) .

Abstract: By using special frequency response manipulation in the difference channel of a stereo signal, the stereo image appears to extend beyond the actual placement of the loudspeakers. This is accomplished by shaping the difference channel response to simulate the response one would be subjected to if the sources were physically moved to the virtual position, and by additionally cancelling the crosstalk effect in each channel.

Abstract: A method for decoding an audio signal includes receiving a digital audio signal having a plurality of channels defined thereon, wherein one of the plurality of channels is a center channel and at least one of the other of said plurality of channels is a remaining audio channel; comparing the center channel with the at least one of the other of the plurality of channels to determine a ratio of the center channel to the other of the plurality of channels; and automatically adjusting the center channel and the at least one of the plurality of other channels when a predetermined value for the ratio is not met.

Abstract: The present invention discloses a differential audio device applicable to notebook computers. The device uses differential signal characters to improve the audio signal quality and its transmission distance. The device contains at least an audio controller to output audio signals, a single-ended signal to differential signal converter to convert audio signals into differential signals, a differential signal to single-ended signal converter to convert differential signals into audio signals for output.

Abstract: A method of generating surround sound with channels processing separately includes steps of transmitting left and right channel signals separately to a first multiple frequency phase shift processor, a pre-set equalizer and a second multiple frequency phase shift processor without addition and subtraction thereby providing a stereo sound position enhancement processing, transmitting left and right space signals separately to two multiple frequency phase shift processors, two stereo signal difference processors and a pre-set equalizer to provide a surround sound enhancement processing, and transmitting left channel signals, left space signals, right channel signals and right space signals separately to respective variable amplifiers to adjust output amplitude after the sound position enhancement processing and the surround sound enhancement processing and then summing up output signals to obtain three dimensional effect enhancement.

Abstract: An audio system for a vehicle that includes a first passenger location and a second passenger location, the second passenger location situated behind the first passenger location, the audio system including a first directional audio channel signal source; a surround audio channel signal source; a first electroacoustical transducer coupled to the first directional audio signal source and to the surround audio channel source, situated forward of the second passenger location and behind the first passenger location. The first electroacoustical transducer radiates sound waves corresponding to audio signals from the first directional audio channel signal source and corresponding to audio signals from the surround audio channel signal source. The system further includes a second electroacoustical transducer coupled to the first directional audio signal source, situated forward of the first electroacoustical transducer.

Abstract: A sound apparatus is constructed for directing a sound image of a virtual sound source at a designated source point to a listener in a virtual sound field. In the sound apparatus, a database provisionally memorizes acoustic transfer characteristics of the virtual sound field in correspondence to reference source points distributed radially around a center point of the listener. Left and right filters respectively filter audio signals of left and right channels according to the acoustic transfer characteristics loaded from the database. A processor computes a leftward acoustic direction from the designated source point to a left ear of the listener, and computes a rightward acoustic direction from the designated source point to a right ear of the listener.

Abstract: An architecture allows two-channel sound effect hardware to output four-channel analog signal, comprising sound effect application program for processing multi-channel information of application software. An operation system kernel program is received the multi-channel information by a multi-channel sound effect interface. Means for transforming a four-channel signal to two-channel signal is coupled to the operation system kernel program to transform a four-channel information to a two-channel information. A two-channel sound effect hardware is coupled to the means for transforming a four-channel signal to two-channel signal. A converter is coupled to the two-channel sound effect hardware to transform the two-channel signal to a four-channel analog signal.

Abstract: A sound processing circuit for distributing low frequency signal components of multichannel audio signals. The sound processing circuit filters low frequency signal components from the digital audio signals of m (m≦n) specified channels using an exclusive channel having low frequency signals and n (n>1) multiple independent channels, and outputs the filtered low frequency signal components as part of a low frequency signal channel.

Abstract: A signal of a whole audio frequency band is input to input lines CHL and CHR having band-split digital band pass filters BFL1 to BFLn and BFR1 to BFRn, attenuators ATL1 to ATLn and ATR1 to ATRn, delay elements ZL1 to ZLn and ZR1 to ZRn, and adders 21 to 24, thereby causing speakers 25 and 26 to generate sounds. The reproduced sounds are picked up by microphones 27 and 28 placed at listening positions. The obtained pick-up signals PR and PL are passed through band-split digital band pass filters BFL1′ to BFLn′ and BFR1′ to BFRn′ which are set to the same bands as those of the band-split digital band pass filters BFL1 to BFRn, to generate test data DL1(t) to DLn(t) and DR1(t) to DRn(t). On a basis of the test data, an interaural correlation coefficient &rgr;RL is calculated.

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.

Abstract: The present invention is directed to a process and device for mixing a plurality of sound signals. The process includes separating each sound signal and selectively delaying each separated sound signal. The process also includes selectively weighting each separated and selectively delayed sound signal and adding corresponding ones of the selectively weighted signals to an intermediary signal. The process also includes separating and filtering each intermediary signal, and adding the intermediary signals to form an output signal. The device for mixing sound signals of a plurality of input channels into a plurality of output channels includes each input channel having a plurality of partial channels, a decoder providing the plurality of outputs, and a plurality of intermediary channels coupled to the plurality of partial channels and to the decoder.

Abstract: M (M is in the plural) sound source signals T1, T2, T3, T4, each having at least one information of position information, movement information and localization information, are synthesized to N sound source signals SL, SR based on this information where N is smaller than the number (M) of the sound source signals and N synthesized sound source signals SL, SR having this synthesized information are localized in virtual sound image An amount of data to be processed can be reduced while virtual reality can be realized by sounds.

Abstract: An automotive audio reproducing apparatus according to the present invention comprises: a sound image position correction circuit 52 for converting a left-channel input digital audio signal XL(Z) and a right-channel input digital audio signal XR(Z) into a digital audio signal YL(Z) and a digital audio signal YR(Z), respectively, for output expressed by: