Orange

France Telecom

Université Du Mans

Rozenn Nicol

Adrien Daniel

Georges Roussel

Julien Faure

Marc Emerit

Alexandre Guerin

Grégory Pallone

François-Gaël Ottogalli

Julien Riera

Cyril Plapous

Gregory Pallone

Katell Peron

Julian Moreira

Pierre Lecomte

Laurent Simon

Manuel Melon

Kais Hassan

Pierre Guillon

Romain Deprez

Julian Palacino

Franck Roudet

Vincent Lemaire

Sylvain Busson

A sound capture device is disclosed, including plural microphone capsules, distributed over portion P of sphere S circumscribed between two or three planes perpendicular to each other, the three planes intersecting at a point corresponding to the center of the sphere S, and the two planes intersecting at a straight line passing through the center of the sphere S, and the sphere portion P being such that P=n S/8, with n=1,2; and a processing unit connected to the capsules to receive the signals captured by the capsules. The processing unit is arranged to matrix the signals in an ambisonic representation which retains only the ambisonic components associated with spherical harmonics that are symmetrical in relation to at least two of the aforementioned planes, and process a matrix thus obtained to identify a sound source surrounding the sphere portion and interpret a sound signal from the source.

Sound capture device with improved microphone array

A computer-assisted method for spatialized sound reproduction based on an array of loudspeakers, for the purpose of producing a selected sound field at a position of a listener. The method includes iteratively and continuously: obtaining a current position of a listener; determining respective acoustic transfer functions of the loudspeakers at a virtual microphone of which the position is defined dynamically as a function of the current position of the listener, estimating a sound pressure at the virtual microphone; calculating an error between the estimated sound pressure and a target sound pressure; calculating and applying respective weights to the control signals of the loudspeakers as a function of the error and of a weight forgetting factor, the forgetting factor being calculated as a function of a movement of the listener, and calculating the sound pressure at the current position of the listener.

Method for the spatialized sound reproduction of a sound field that is audible in a position of a moving listener and system implementing such a method

A method for spatialized sound reproduction using an array of loudspeakers, to generate a chosen sound field selectively audible in a first predetermined sub-area of an area covered by the loudspeakers, the area further including a second sub-area in which the chosen sound field is inaudible. The loudspeakers are supplied with respective control signals so that each one continuously emits an audio signal. The method includes, iteratively and continuously: estimating a sound pressure in the second sub-area as a function of the respective control signals of the loudspeakers, and of a respective initial weight of the control signals; calculating an error between the estimated sound pressure and a target sound pressure in the second sub-area; and, calculating and applying respective weights to the control signals, based on the error. The sound pressure in the second sub-area is calculated again based on the respective weighted control signals of the loudspeakers.

Method for the spatialized sound reproduction of a sound field which is selectively audible in a sub-area of an area

Systems and methods are disclosed for modelling of individual acoustic transfer functions relative to the audition of an individual in three-dimensional space. A method is provided for modelling sets of acoustic transfer functions specific to an individual according to a multiplicity of directions in space, where a set of acoustic transfer functions specific to the individual in a given direction is determined depending on the result of a statistical analysis of a plurality of distinct stimuli emitted in the direction of the individual. A stimulus can be dependent on at least one set of predetermined acoustic transfer functions that are associated with the given direction, and on responses received from the individual to each emitted stimulus.

System for modelling acoustic transfer functions and reproducing three-dimensional sound

The present invention relates to the management of devices (AP, AP, AP) connected to an equipment item (EQ) in an environment (ENV). The equipment item receives and interprets signals from the environment (S, S, S) and, based on an interpretation of the signals, transmits adjustment instructions (C, C, C) to the devices. In particular, there is provided a sound sensor (ANT) connected to the equipment item (EQ), and one or more mechanical members (OM, OM) which when actuated for the purpose of adjusting at least one of the devices, causes the emission of a characteristic sound (S, S). The equipment item, upon receiving these sound signals from the environment, compares each sound signal to acoustic signatures predefined in a correlation table (TAB) which lists adjustment instructions (C, C, . . . ) according to these acoustic signatures (S, S; S, S, S; . . . ) and transmits an adjustment instruction for a device based on at least one acoustic signature of the table, recognized in the received sound signals.

Adjustment control for one or more devices

A data-processing method for determining at least one spatial coordinate of a sound source emitting a sound signal, in a three-dimensional space, includes the following steps: obtaining at least one first signal and one second signal from the sound signal, collected according to separate directivities by a first sensor and a second sensor; deducing from the first and second signals an expression of at least one first spatial coordinate of the sound source, the expression comprising an uncertainty; determining additional information relating to the first spatial coordinate of the sound source, from a comparison between the respective features of the signals collected by the first and second sensors; and determining the first spatial coordinate of the sound source on the basis of the expression and the additional information.

Acquisition of spatialized sound data

A method of calibrating a sound restitution assembly for a multichannel sound signal, which includes a plurality of loudspeakers. The method includes: obtaining multidirectional impulse responses of the loudspeakers to reproduction of a predetermined audio signal; analyzing the multidirectional impulse responses obtained, in a domain of spatio-temporal representation, over at least one time window encompassing the instants of arrival of the first reflections of the audio signal reproduced to determine a set of characteristics of the first reflections; comparing the amplitude of each of the reflections with a predetermined perceptibility threshold and identifying imperceptible reflections for which the amplitude is below the predetermined threshold; modifying the impulse responses obtained to obtain perceptive impulse responses, by deleting the reflections identified as imperceptible; and determining a filtering matrix on the basis of the perceptive impulse responses for an application of this filtering matrix to the multichannel audio signal before sound restitution.

Optimized calibration of a multi-loudspeaker sound playback system

A method is provided for allocating bits for quantifying spatial information parameters by frequency sub-band for parametric encoding/decoding of a multichannel audio stream representative of a soundstage consisting of a plurality of sound sources. The method includes a step of quantifying or inversely quantifying, by frequency sub-band, spatial information parameters for the sound sources of the soundscape. The method further includes: assessing a spatial resolution of the current sub-band on the basis of the spectral properties of the sub-band; and determining a number of bits to be allocated to the current sub-band, the number of bits to be allocated being inversely proportional to the estimated spatial resolution. Also provided is a device for allocating quantification bits implementing the above-described method.

Allocation, by sub-bands, of bits for quantifying spatial information parameters for parametric encoding

A method for compressing an audio stream, including a plurality of signals, describing a sound scene produced by a plurality of sources in a space, by: identifying the sources from an audio stream; determining a frequency band, energy level and spatial position in the space for each of the identified sources; determining, for each identified source, a spatial resolution corresponding to the smallest difference in position of said source in the space which a listener is capable of perceiving, on the basis of: the frequency band, the energy level, and the spatial position of said source; and, on the frequency band, energy level, and spatial position of at least one subset of the other identified sources; generating a compressed stream comprising the information required to restore each identified source with at least the same corresponding spatial resolution.

Multichannel audio stream compression

Processing of sound data encoded in a sub-band domain, for dual-channel playback of binaural or Transaural&#xae; type is provided, in which a matrix filtering is applied so as to pass from a sound representation with N channels with N&#x3e;0, to a dual-channel representation. This sound representation with N channels comprises considering N virtual loudspeakers surrounding the head of a listener, and, for each virtual loudspeaker of at least some of the loudspeakers: a first transfer function specific to an ipsilateral path from the loudspeaker to a first ear of the listener, facing the loudspeaker, and a second transfer function specific to a contralateral path from said loudspeaker to the second ear of the listener, masked from the loudspeaker by the listener's head. The matrix filtering comprises a multiplicative coefficient defined by the spectrum, in the sub-band domain, of the second transfer function deconvolved with the first transfer function.

Processing of sound data encoded in a sub-band domain

The invention relates to a method for determining transfer functions of the HRTF type for an individual, that includes: measuring, for a first number of directions, the transfer functions of the HRTF type specific to the individual; matching the directivity functions associated with the measured functions of the HRTF type, with reference directivity functions associated with reference transfer functions of the HRTF type, the reference functions of the HRTF type being determined for a second number of directions higher that the first number of directions and reconstructing the measured directivity functions from the reference directivity functions.

Method and device for determining transfer functions of the HRTF type

The invention concerns a method for three-dimensional spatialization of audio channels from a filter BRIR incorporating a theater effect. For a specific number N of samples corresponding to the size of the pulse response of the BRIR filter, it consists in breaking down (A) the BRIR filter into at least a set of delay and amplitude values associated with the times of arrival of reflections; extracting (B) on the number of B samples at least one spectral module of the BRIR filter; and constituting (C) from each successive delay, its amplitude and its spectral module associated with an elementary BRIR filter (BRIR) directly applied to the audio channels in the time, frequency or transformed domain. The invention is applicable to binaural or multichannel spatialization.

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La Roche Derrien, France

Rozenn Nicol