669 results about "Sound image" patented technology

A digital wavetable audio synthesizer is described. The synthesizer can generate up to 32 high-quality audio digital signals or voices, including delay-based effects, at either a 44.1 KHz sample rate or at sample rates compatible with a prior art wavetable synthesizer. The synthesizer includes an address generator which has several modes of addressing wavetable data. The address generator's addressing rate controls the pitch of the synthesizer's output signal. The synthesizer performs a 10-bit interpolation, using the wavetable data addressed by the address generator, to interpolate additional data samples. When the address generator loops through a block of data, the signal path interpolates between the data at the end and start addresses of the block of data to prevent discontinuities in the generated signal. A synthesizer volume generator, which has several modes of controlling the volume, adds envelope, right offset, left offset, and effects volume to the data. The data can be placed in one of sixteen fixed stereo pan positions, or left and right offsets can be programmed to place the data anywhere in the stereo field. The left and right offset values can also be programmed to control the overall volume. Zipper noise is prevented by controlling the volume increment. A synthesizer LFO generator can add LFO variation to: (i) the wavetable data addressing rate, for creating a vibrato effect; and (ii) a voice's volume, for creating a tremolo effect. Generated data to be output from the synthesizer is stored in left and right accumulators. However, when creating delay-based effects, data is stored in one of several effects accumulators. This data is then written to a wavetable. The difference between the wavetable write and read addresses for this data provides a delay for echo and reverb effects. LFO variations added to the read address create chorus and flange effects. The volume of the delay-based effects data can be attenuated to provide volume decay for an echo effect. After the delay-based effects processing, the data can be provided with left and right offset volume components which determine how much of the effect is heard and its stereo position. The data is then stored in the left and right accumulators.

A method for synthesizing a binaural audio signal, the method comprising: inputting a parametrically encoded audio signal comprising at least one combined signal of a plurality of audio channels and one or more corresponding sets of side information describing a multi-channel sound image; and applying a predetermined set of head-related transfer function filters to the at least one combined signal in proportion determined by the corresponding set of side information to synthesize a binaural audio signal. A corresponding parametric audio decoder, parametric audio encoder, computer program product, and apparatus for synthesizing a binaural audio signal are also described.

Inputting of a parametrically encoded audio signal comprising at least one combined signal of a plurality of audio channels and one or more corresponding sets of side information describing a multi-channel sound image and including channel configuration information is shown along with deriving, from the channel configuration information, audio source location data describing at least one of horizontal and vertical positions of audio sources in the binaural audio signal; selecting, from a predetermined set of head-related transfer function filters, a left-right pair of head-related transfer function filters matching closest to the audio source location data, wherein the left-right pair of head-related transfer function filters is searched in a stepwise motion in a horizontal plane; and synthesizing a binaural audio signal from the at least one processed signal according to side information and the channel configuration information.

Using an M:N variable matrix, M audio input signals, each associated with a direction, are translated to N audio output signals, each associated with a direction, wherein N is larger than M, M is two or more and N is a positive integer equal to three or more. The variable matrix is controlled in response to measures of: (1) the relative levels of the input signals, and (2) the cross-correlation of the input signals so that a soundfield generated by the output signals has a compact sound image in the nominal ongoing primary direction of the input signals when the input signals are highly correlated, the image spreading from compact to broad as the correlation decreases and progressively splitting into multiple compact sound images, each in a direction associated with an input signal, as the correlation continues to decrease to highly uncorrelated.

In a sound source display system, an omnidirectional camera captures an image of a monitoring area. A microphone array collects a voice in the monitoring area. A monitoring monitor displays the image of an imaging area captured by the omnidirectional camera. A sound pressure calculator in a directivity control device calculates a sound pressure indicating a source of a sound in the image of the imaging area using voice data of the voice collected by the microphone array. An output controller in the directivity control device compares the sound pressure and threshold values (first threshold value, second threshold value), and causes sound image information in which the sound pressure is converted into visual information according to the result of comparison, to be displayed on the monitoring monitor so as to be superimposed on the image of the imaging area.

A method for synthesizing a binaural audio signal, the method comprising: inputting a parametrically encoded audio signal comprising at least one combined signal of a plurality of audio channels and one or more corresponding sets of side information describing a multi-channel sound image; and applying a predetermined set of head-related transfer function filters to the at least one combined signal in proportion determined by said corresponding set of side information to synthesize a binaural audio signal.

An acoustic correction apparatus processes a pair of left and right input signals to compensate for spatial distortion as a function of frequency when said input signals are reproduced through loudspeakers in a sound system. The sound-energy of the left and right input signals is separated and corrected in a first low-frequency range and a second high-frequency range. The resultant signals are recombined to create image-corrected audio signals having a desired sound-pressure response when reproduced by the loudspeakers in the sound system. The desired sound-pressure response creates an apparent sound image location with respect to a listener. The image-corrected signals can also be spatially-enhanced to broaden the apparent sound image and improve the low frequency characteristics of the sound when played on small loudspeakers.

An audio signal processing method comprises the steps of emitting a sound at a virtual sound image location in space on the outer side of a closed surface, generating measurement-based directional transfer functions corresponding to a plurality of positions on the closed surface based on a result of measuring the sound at the plurality of respective positions on the closed surface by using a directional microphone, generating composite transfer functions corresponding to the plurality of respective positions on the closed surface by respectively adding, at a specified ratio, the measurement-based directional transfer functions and auxiliary transfer functions and generating reproduction audio signals corresponding to the plurality of respective positions on the closed surface by performing a calculation process on an input audio signal in accordance with the set of composite functions.

There are provided: a means (101a) for storing standard head related transfer functions for reference positions from a virtual listener; a means (101) for, when given information (DIR, DIST) about a virtual sound source position, forming head related transfer functions (hL(k), hR(k)) as left ear and right ear head related transfer functions by selecting one of the stored standard head related transfer functions or by selecting two or more of them and interpolating; means (102, 103) for imprinting a sense of direction and distance on the audio listening signal by using the head related transfer functions thus obtained; and means (104, 105) for correcting a distance related to the obtained head related transfer functions and the sense of distance to the virtual sound source position, in the audio listening signals (sL(n), sR(n)) given the sense of direction and distance or the source audio listening signal (s(n)). A highly precise sense of distance can be provided in a small structure.

A headphone apparatus is presented so that a sound image of game sound outputted from an on-line game machine having a communication function is localized at one or more positions out of the head of the listener wearing a headphone while a sound image of an opponent player's voice outputted from the game machine is localized at a position in the head of the listener.

The object of the present invention is to provide a stereoscopic video and audio recording method, a stereoscopic video and audio recording medium, a stereoscopic video and audio reproducing method, a stereoscopic video and audio recording apparatus, and a stereoscopic video and audio reproducing apparatus. An audio information storage region for three-dimensional video is arranged in advance, separately from audio information for ordinary two-dimensional video, in a media recording format for recording stereoscopic video and audio. Therefore, when stereoscopic reproduction is selected, an audio can be reproduced with realistic sensation in a depth direction in sound-image processing or surround processing.

A head-related transfer function (HRTF) convolution method arranged, when an audio signal is reproduced acoustically by an electro-acoustic conversion unit disposed in a nearby position of both ears of a listener, to convolute an HRTF into the audio signal, which allows the listener to listen to the audio signal such that a sound image is localized in a perceived virtual sound image localization position, the method including the steps of: measuring, when a sound source is disposed in the virtual sound image localization position, and a sound-collecting unit is disposed in the position of the electro-acoustic conversion unit, a direct-wave direction HRTF regarding the direction of a direct wave, and reflected-wave direction HRTFs regarding the directions of selected one or more reflected waves, from the sound source to the sound-collecting unit, separately beforehand; and convoluting the obtained direct-wave direction HRTF, and the reflected-wave direction HRTFs into the audio signal.

The sound image control device filters transfer functions H3 and H1 indicating transfer characteristics of a sound from an acoustic transducer (8) to entrances to respective ear canals (1) and (2) as well as filtering transfer functions H4 and H2 from an acoustic transducer (9) to the entrances to the respective ear canals (1) and (2) and generates second transfer functions H6 and H5 indicating transfer characteristics of a sound to the entrances to the respective ear canals (1) and (2) from a target sound source (11) at a location different from the sound sources, the sound image control device being equipped with correction filters (13) and (14) that (i) store characteristic functions E1 and E2 for performing filtering operations on the first transfer functions H1, H2, H3, and H4 and (ii) generate the second transfer functions H5 and H6 from the first transfer functions H1, H2, H3, and H4 using such characteristic functions E1 and E2.

An acoustic correction apparatus processes a pair of left and right input signals to compensate for spatial distortion as a function of frequency when the input signals are reproduced through speakers in a sound system. The sound-energy of the left and right input signals is separated and corrected in a first low-frequency range and a second high-frequency range. The resultant signals are recombined to create image-corrected audio signals having a desired sound-pressure response when reproduced by the speakers in the sound system. The desired sound-pressure response creates an apparent sound image location with respect to a listener. The image-corrected signals may then be spatially enhanced to broaden the apparent sound image.

A sound reproducing system includes a first speaker that is supplied with audio signals of a first channel and that is placed so that a reproduced sound image generated by the audio signals of the first channel is localized in a position in a front direction of a listener; a pair of second speakers that are supplied with audio signals on which a virtual sound source process is performed; a virtual sound source processing unit to perform the virtual sound source process on the audio signals of a plurality of channels; a volume detecting unit to detect the volumes of the first channel and the other channels; a volume comparing unit to compare the volume of the first channel with each of the volumes of the other channels; and a control unit to control the gains of the audio signals of the first channel and the other channels.

The invention discloses a fault detecting device of near field acoustic holography sound image mode identification and a detecting method thereof in the field of industrial detection. The device comprises a microphone array, a scanner frame, a reference source, a clamped rib plate, an excitation source and a data acquiring system. The invention adopts sound pressure amplitude and distribution changes under mechanical normal and fault states, borrows ideas from applications of an image diagnosis technology in other fields and utilizes image processing, feature extracting and mode identifying technologies to process a near field acoustic holography image. Experiments show that the method is effective, vibration source positioning and identifying functions coordinated with the holographic imaging technology is proven, the image feather extracting and mode identifying technologies are combined with the acoustic imaging technology, thus broadening the application range of the acoustic imaging technology and bringing a set of effective acoustic fault diagnosis technologies and feasibility of being widely used in engineering thereof.

The invention particularly relates to an audio / video combined monitoring method and a system thereof, belongs to the technical field of industrial environment monitoring, and aims to solve the problems in the prior art, for example, the monitoring is only conducted by video monitoring operators on duty, who are easy to be fatigue and hardly identify places with potential safety hazards, moreover, video monitoring is limited by functions and viewing angles, so that the potential hazard cannot be found in time, thereby missing rescue opportunities. The audio / video combined monitoring method uses audio signals and video signals at the same time to conduct environmental monitoring, and guides the operators on duty to selectively observe video windows by using the identification results of the audio signals. The processing method of the audio signals comprises the following steps: (1) feature extraction, (2) model training, (3) sound classification, (4) online study, and (5) hazard rating evaluation.

An audio reproducing system includes a pair of speaker units, a mounting unit for mounting the pair of speaker units, without being attached to a baffle board, to the vicinity of a listener's ears in a manner such that sounds emitted from the front and back of a diaphragm of each speaker unit are mixed, and an audio signal output unit for virtual sound imaging an input audio signal and outputting the virtual sound imaged signal to the pair of speaker units in a manner such that the listener listens to a sound reproduced by the pair of speaker units feeling as if the sound is emitted from a different speaker device.

Methods and apparatuses for encoding and decoding an object-based audio signal are provided. The method of decoding an object-based audio signal includes extracting a down-mix signal and object-based parameter information from an input audio signal, generating an object-audio signal using the down-mix signal and the object-based parameter information, and generating an object audio signal with three-dimensional (3D) effects by applying 3D information to the object audio signal. Accordingly, it is possible to localize a sound image for each object audio signal and thus provide a vivid sense of reality during the reproduction of object audio signals.

A digital wavetable audio synthesizer is described. A synthesizer volume generator, which has several modes of controlling the volume, adds envelope, right offset, left offset, and effects volume to the data. The data can be placed in one of sixteen fixed stereo pan positions, or left and right offsets can be programmed to place the data anywhere in the stereo field. The left and right offset values can also be programmed to control the overall volume. Zipper noise is prevented by controlling the volume increment. A synthesizer LFO generator can ad LFO variation to: (i) the wavetable data addressing rate, for creating a vibrato effect; and (ii) a voice's volume, for creating a tremolo effect. Generated data to be output from the synthesizer is stored in left and right accumulators. However, when creating delay-based effects, data is stored in one of several effects accumulators. This data is then written to a wavetable. The difference between the wavetable write and read addresses for this data provides a delay for echo and reverb effects. LFO variations added to the read address create a chorus and flange effects. The volume of the delay-based effects data can be attenuated to provide volume decay for an echo effect. After the delay-based effects processing, the data can be provided with left and right offset volume components which determine how much of the effect is heard and its stereo position. The data is then stored in the left and right accumulators.

An audio signal processing apparatus includes: a division section that divides at least two or more channel audio signals into components in a plurality of frequency bands; a phase difference calculation section that calculates a phase difference between the two or more channel audio signals at each the frequency band; a level ratio calculation section that calculates a level ratio between the two or more channel audio signals at each the frequency band; a sound image localization estimation section that estimates, based on the level ratio or the phase difference, sound image localization at each the frequency band; and a control section that controls the estimated sound image localization at each the frequency band by adjusting the level ratio or the phase difference.

A sound image localization device which includes a signal source for outputting an audio signal, a signal divider for dividing the audio signal output from the signal source into two digital audio signals respectively for two channels, and a first signal processor for receiving one of the two digital signals and processing the digital signal so as to localize a virtual sound image using a filter having a first frequency characteristic. In addition, the sound image localization device includes a first D / A converter for converting the digital signal output from the first signal processor into an analog signal, a second D / A converter for receiving the other digital signal obtained from the signal divider and converting the signal into an analog signal, a first control speaker for outputting the audio signal obtained by the first D / A converter to a prescribed space area; and a second control speaker for outputting the audio signal obtained by the second D / A converter to a prescribed space area.

An audio signal high frequency component controlled in terms of directivity is reproduced, or an audio signal high frequency component compensated in terms of frequency characteristic or controlled in terms of directivity is reproduced, such that the reflected sound comes from a direction in which the high frequency component is intended to be localized. The sound pressure in a seat where a desired localization effect is not provided due to the arrangement of speakers is compensated such that the interaural amplitude level in the seat is equal to that of another seat. Thus, an equivalent level of localization effect is provided in a plurality of seats, especially for an audio signal high frequency component, without significantly increasing the number of the speakers.

An audio signal processing device includes: head related transfer function convolution processing units convoluting head related transfer functions with audio signals of respective channels of plural channels, which allow the listener to listen to sound so that sound images are localized at assumed virtual sound image localization positions concerning respective channels of the plural channels of two or more channels when sound is reproduced by electro-acoustic transducer means; and 2-channel signal generation means for generating 2-channel audio signals to be supplied to the electro-acoustic transducer means from audio signals of plural channels from the head related transfer function convolution processing units, wherein, in the head related transfer function convolution processing units, at least a head related transfer function concerning direct waves from the assumed virtual image localization positions concerning a left channel and a right channel in the plural channels to both ears of the listener is not convoluted.

An acoustic correction apparatus processes a pair of left and right input signals to compensate for spatial distortion as a function of frequency when the input signals are reproduced through speakers in a sound system. The sound-energy of the left and right input signals is separated and corrected in a first low-frequency range and a second high-frequency range. The resultant signals are recombined to create image-corrected audio signals having a desired sound-pressure response when reproduced by the speakers in the sound system. The desired sound-pressure response creates an apparent sound image location with respect to a listener. The image-corrected signals may then be spatially enhanced to broaden the apparent sound image.

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.

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.

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. An output position adjustor controls the at least one audio signal, with respect to which the plurality of first virtual sound images are formed by the virtual sound image forming unit, with the adjusting factors generated by the controller and adjusts positions of the at least one second virtual sound image. An adder sums up left output related signals of the at least one audio signal with respect to which the position of the at least one second virtual sound image is adjusted, and sums up right output related signals of the at least one audio signal with respect to which the position of the at least one second virtual sound image is adjusted, to generate left and right audio signals for forming the at least one second virtual sound image.

An effects and recording system is provided which is capable of recording at least one of a received audio signal and a processed audio signal generated by the application of musical effects to the received audio signal. The audio signal may be captured from any device capable of producing an audio signal. The effects and recording system may provide various recording capabilities including auto track selection and arming, automatic signal routing, delayed recording initialization, automatic level setting and panning settings, editing capabilities, and the merging of recorded tracks. Additionally, the effects and recording system may provide various monitoring capabilities, including automatic level, panning, and / or effects or other filtering of signals recorded or monitored via the system, as well as an enhanced mix-down feature, and music mix-down type.