WO1999027520A1 - Active soundproofing method and device - Google Patents

Active soundproofing method and device Download PDF

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Publication number
WO1999027520A1
WO1999027520A1 PCT/FR1998/002468 FR9802468W WO9927520A1 WO 1999027520 A1 WO1999027520 A1 WO 1999027520A1 FR 9802468 W FR9802468 W FR 9802468W WO 9927520 A1 WO9927520 A1 WO 9927520A1
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WO
WIPO (PCT)
Prior art keywords
electrical
electrical signal
noise
signal
space
Prior art date
Application number
PCT/FR1998/002468
Other languages
French (fr)
Inventor
Jean-Claude Decaux
Jacques Lewiner
Bruno Salle
Damien Lebrun
Sylvain Javelot
Original Assignee
Decaux Jean Claude
Jacques Lewiner
Bruno Salle
Damien Lebrun
Sylvain Javelot
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Decaux Jean Claude, Jacques Lewiner, Bruno Salle, Damien Lebrun, Sylvain Javelot filed Critical Decaux Jean Claude
Priority to EP98955694A priority Critical patent/EP1032932A1/en
Priority to AU12446/99A priority patent/AU1244699A/en
Priority to JP2000522581A priority patent/JP2001524701A/en
Publication of WO1999027520A1 publication Critical patent/WO1999027520A1/en

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Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17813—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
    • G10K11/17817—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the output signals and the error signals, i.e. secondary path
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17821—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the input signals only
    • G10K11/17825—Error signals
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17853—Methods, e.g. algorithms; Devices of the filter
    • G10K11/17854—Methods, e.g. algorithms; Devices of the filter the filter being an adaptive filter
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1787—General system configurations
    • G10K11/17879—General system configurations using both a reference signal and an error signal
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G10K2210/12—Rooms, e.g. ANC inside a room, office, concert hall or automobile cabin
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/301—Computational
    • G10K2210/3053—Speeding up computation or convergence, or decreasing the computational load

Definitions

  • the present invention relates to methods and devices for active soundproofing. More particularly, the invention relates to a method for soundproofing a space receiving noise, by emitting noise in said space.
  • the document EP-A-0 601 934 describes an example of such a method, in which: - the noises to be attenuated are captured outside the space to be soundproofed, by means of microphones, the noises are calculated during the propagation of the noises towards the space to be soundproofed, then said noises are emitted so that they arrive in said space to be soundproofed at the same time as the noises to be attenuated.
  • the process described in this document is satisfactory, in particular for attenuating random noises such as those coming from the street, but it nevertheless has the disadvantage that the counter noises must be calculated and emitted extremely quickly before the noises to be attenuated reach the space to be soundproofed, which limits the volume of the calculations made to determine the noise abatements, and therefore the quality of the soundproofing.
  • the object of the present invention is in particular to overcome this drawback, when the noises to be attenuated are emitted by an electric sound generating apparatus such as a radio, television receiver, a hi-fi system, or the like.
  • a method of the kind in question is essentially characterized in that an electrical signal known as a reference signal, used read by an electrical sound generator which transforms this reference electrical signal into sound waves at the origin of at least part of the noise to be attenuated, this acquisition being carried out directly by electromagnetic means (for example, direct acquisition of the electrical signal by wire, acquisition by capturing a wave, radio or light, modulated as a function of the reference signal, or others) at the latest when the electric sound generating apparatus transforms said electric reference signal into sound waves, and what one determines the noises according to this electrical reference signal.
  • electromagnetic means for example, direct acquisition of the electrical signal by wire, acquisition by capturing a wave, radio or light, modulated as a function of the reference signal, or others
  • the signal which is used to determine the noises is acquired at the latest when the noises are emitted, whereas in the methods of the prior art, this signal was acquired by transducers, for example microphones, that after the sound waves at the origin of the noises have already traveled a certain distance: the invention avoids this delay in acquiring the reference signal used to determine the noises, which makes it possible to have more time to determine said counter noises, and therefore to use a process for preparing said noises which is finer and more efficient than in the subsequent art.
  • the counter-noises are emitted by means of a non-zero number n high -speakers, and the noise countermeasures are also determined as a function of data relating to the propagation of sounds, on the one hand, between the electrical sound generating apparatus and the space to be soundproofed, and on the other hand, between the loudspeakers and the space to be soundproofed;
  • h ⁇ :, (- t) represents the time feedback of the impulse response h 1D (t), previously determined and stored, between the speaker i and a predetermined point j called "calibration" belonging to the space to be soundproofed, the space to be soundproofed comprising a non-zero number p of calibration points
  • the impulse response h 1D (t) corresponding to the acoustic signal received at point j when the loudspeaker i emits a short acoustic pulse
  • g D (t) is the impulse response, previously determined and stored, between the sound-generating electrical apparatus and the calibration point j, this impulse response g ** (t) corresponding to the acoustic signal received at the calibration point j when the electric sound generator emits a short acoustic pulse
  • S (t) is an estimate of the acoustic signal emitted by the electric sound generating apparatus, this estimate being determined as a function of the reference electric signal, and ⁇ £> denotes the convolution product;
  • S (t) is expressed in the form As (t), where A is a constant coefficient at least by periods and s (t) is a signal determined directly from the electric signal reference point, and the noise in the space to be soundproofed is measured to determine the coefficient A; the coefficient A is determined by a process of minimizing the noise in the space to be soundproofed.
  • the subject of the invention is also a device for implementing a method as defined above, this device comprising: an electromagnetic acquisition system for acquiring the reference electrical signal, - a electronic central unit which is connected electromagnetically (radio link, electric wire link, fiber optic link, or the like) to the acquisition system and which is suitable for determining noise abatements, - and a non-zero number n of loudspeakers which are connected to the electronic central unit to emit the noise towards the space to be soundproofed.
  • the device comprises the electrical sound generating apparatus, and the device d acquisition is integrated into this electrical appliance;
  • the electrical sound generator is adapted to generate the sound waves corresponding to the reference electrical signal with a certain delay with respect to the acquisition of said reference electrical signal by the acquisition device; - said delay is between 0.01 and 2 seconds;
  • the sound generating electrical apparatus also generates images, with the same delay as for the generation of said sound waves;
  • the acquisition device is connected to the electrical sound generator;
  • the electrical sound generating apparatus is a receiver adapted to receive said reference electrical signal on a reception channel from a number of predetermined reception channels, the acquisition device itself being a receiver which is independent of said electrical apparatus sound generator and which is adapted to receive an electrical signal on a reception channel among said predetermined reception channels, the device further comprising means for selecting the reception channel on which the reference electrical signal is received;
  • the device further comprises at least one microphone which is adapted to receive the noises generated by the
  • FIG. 1 is a diagrammatic view illustrating a first embodiment of the invention
  • FIG. 2 is a diagrammatic view of the electrical sound generator apparatus for which noise is sought to be reduced, in a second embodiment embodiment of the invention
  • FIG. 3 is a schematic view similar to FIG. 1, illustrating a third embodiment of the invention.
  • the same references designate identical or similar elements.
  • the electrical sound generating device is a television receiver, but it could be any other electrical device which transforms an analog or digital electrical signal, known as the reference electrical signal, into sound waves at the origin at least some of the noise that we are trying to reduce in space 1.
  • the electrical sound generating device could also be constituted by a radio receiver, an optical disc player, a microgroove disc player, a magnetic tape player (presented or not in the form of a cassette), a loudspeaker receiving by wire or other means the signal to be broadcast, etc., or a combination of these.
  • the electrical sound generating appliance whose noise is sought to be attenuated is generally located in another room 5 of the same building 3 as space 1, but this appliance could also be located outside of building 3, for example when trying to attenuate the noises coming from a street sound system or an outdoor concert sound system.
  • the space 1 to be soundproofed could if necessary be located outside a building.
  • the soundproofing of the space 1 is carried out by generating in this space counter-noise, in phase opposition with the noise coming from the electrical apparatus 4 generating sounds.
  • noises are generated by a number n, at least equal to 1 and generally at least equal to 2, of loudspeakers 6 controlled by an electronic central unit 7, which generally consists of a computer connected by wire or wireless to the high -speakers 6 by means of analog-digital converters integrated for example into said computer.
  • the computer 7 is also connected electromagnetically to the sound generating electrical device 4, so as to receive from this device the above-mentioned reference electrical signal.
  • This electromagnetic link can be made by wire (point-to-point link or home automation bus, by solid cable, by coaxial cable or by optical fiber) or by radio, as in the example shown in FIG. 1.
  • the computer 7 is connected to a radio receiver 8 while a radio transmitter 9 is connected to the television 4, for example by means of the audio output or the "Scart" socket of this television. or any other interface, for transmitting the reference electrical signal to the receiver 8 and the computer 7.
  • the computer 7 Given the fact that the acquisition and transmission of the reference electrical signal by electromagnetic means is almost instantaneous in comparison with the propagation of the sound, the computer 7 thus knows the reference signal s (t) corresponding to the emitted sound signal by the electric sound generator 4, well before this sound signal reaches room 2. The computer 7 thus has maximum time to optimally assess the noise to be emitted by the various speakers 6.
  • This determination of the noises can be carried out by any known means, for example by adaptive filtering for example as taught in the document EP-A-0 505 949 (see FIG. 16 of this document, where the signal s (t) would be applied to the circuit in place of the signal from the microphone 25 of said FIG. 16), or according to a method similar to the method taught in document EP-A-0 601 934. ⁇
  • the impulse responses h ⁇ ;) (t) and g-- (t) can be measured for example by placing a microphone 11 successively at the different calibration points 10 (or by placing several microphones simultaneously at the different points 10) and by transmitting the aforementioned acoustic pulses by the loudspeakers 6, and from the location of the electric sound generating apparatus 4, this microphone 11 being connected to the computer 7 by wire or wireless, by means of an analog converter- digital integrated into said computer so that the impulse responses can be acquired and stored by the computer 7.
  • the computer 7 then sends a signal from each speaker i where: h ⁇ ;) (-t) represents the time return of the impulse response h 1D (t),
  • S (t) is an estimate of the acoustic signal emitted by the sound-generating electrical device, this estimate being determined as a function of the reference electrical signal s (t), and ® denotes the convolution product.
  • f (t) the convolution product of a function f (t) by a function g (t) is worth:
  • the computer 7 In order to evaluate the coefficient A, it is possible for example to leave the microphone 11 (or more microphones) permanently in the space 1 to be soundproofed, and the computer 7 gradually varies the coefficient A so as to minimize the noise perceived by said microphone.
  • This minimization process can be implemented continuously or at close time intervals by the computer 7, or even when the microphone 11 measures a noise level above a determined threshold, in the case where the use of the device 4 would have changed the volume of this device. If necessary, the coefficient A (or the estimate S (t)) could be transmitted by the transmitter 9 from data acquired directly in the device 4.
  • the radio transmitter 9 ′ or any other device for acquiring the reference electrical signal s (t), could be integrated into the electric sound generator 4 which would then be an integral part of the active soundproofing device according to the invention.
  • the electrical sound generator 4 can be adapted to generate the sound waves corresponding to the reference electrical signal with a certain delay with respect to the acquisition of said signal by the transmitter 9, this delay possibly being for example between 0.01 and 2 seconds: it is thus possible to give additional time to the computer 7 to optimally determine the noise to be emitted by the different speakers 6.
  • the device 4 also generates images, such as in the case of a television receiver, it generates these images with the same delay as for sound waves.
  • the electrical sound generator 4 is a radio or television receiver, or more generally any device adapted to receive the electrical signal reference s (t) on a reception channel among a certain number of predetermined reception channels, it is possibly possible to avoid connecting or integrating with this apparatus 4 a special device for acquiring the reference electric signal.
  • an acquisition device 12 is used, consisting of a receiver which is independent of the receiver 4 and which is connected to the computer 7.
  • This receiver 12 is similar to the receiver 4, and it is adapted to receive electrical signals on the same reception channels as the receiver 4.
  • the receiver 12 can for example be controlled by the computer 7, so as to scan the various reception channels, the computer 7 then comparing the electrical signals thus received with the electrical signals coming from the microphone 11.
  • the computer 7 can select a reception channel, on which the electrical signal closest to the signal from the microphone is received, the electrical signal s (t) received on this reception channel being then used by the computer 7 as an electrical reference signal.
  • This process can be implemented at regular time intervals by the computer 7, or when the noise level measured by the microphone 11 exceeds a certain threshold, in the case where the user of the receiver 4 has changed the reception channel.
  • noise emitted according to the invention could be superimposed on the noise calculated according to the prior art from measurements made by microphones located inside the space 1, to attenuate the noises other than those generated by the electrical sound generator 4.

Abstract

The invention concerns a method for soundproofing a space (1) receiving noises, by emitting counternoises in said space, which consists in acquiring an electric signal used by an electric sound-generating apparatus (4) which transforms said electric signal into sound waves causing at least part of the noises to be attenuated, said acquisition being carried out at latest at the time when the sound-generating electric apparatus transforms said electric signal into sound waves, and in determining the counternoises on the basis of said electric signals.

Description

Procédé et dispositif d'insonorisation active.Method and device for active soundproofing.
La présente invention est relative aux procédés et dispositifs d'insonorisation active. Plus particulièrement, l'invention concerne un procédé pour insonoriser un espace recevant des bruits, en émettant des contrebruits dans ledit espace.The present invention relates to methods and devices for active soundproofing. More particularly, the invention relates to a method for soundproofing a space receiving noise, by emitting noise in said space.
Le document EP-A-0 601 934 décrit un exemple d'un tel procédé, dans lequel : - on capte les bruits à atténuer à l'extérieur de l'espace à insonoriser, au moyen de microphones, on calcule les contrebruits pendant la propagation des bruits vers l'espace à insonoriser, puis on émet lesdits contrebruits de façon qu'ils parviennent dans ledit espace à insonoriser en même temps que les bruits à atténuer.The document EP-A-0 601 934 describes an example of such a method, in which: - the noises to be attenuated are captured outside the space to be soundproofed, by means of microphones, the noises are calculated during the propagation of the noises towards the space to be soundproofed, then said noises are emitted so that they arrive in said space to be soundproofed at the same time as the noises to be attenuated.
Le procédé décrit dans ce document donne satisfaction, notamment pour atténuer des bruits aléatoires tels que ceux provenant de la rue, mais il présente néanmoins l'inconvénient que les contrebruits doivent être calculés et émis extrêmement rapidement avant que les bruits à atténuer n'atteignent l'espace à insonoriser, ce qui limite le volume des calculs effectués pour déterminer les contrebruits, et donc la qualité de l'insonorisation. La présente invention a notamment pour but de pallier cet inconvénient, lorsque les bruits à atténuer sont émis par un appareil électrique générateur de sons tel qu'un récepteur de radio, de télévision, une chaîne hi-fi, ou similaires. A cet effet, selon l'invention, un procédé du genre en question est essentiellement caractérisé en ce qu'on acquiert un signal électrique dit de référence, uti- lise par un appareil électrique générateur de sons qui transforme ce signal électrique de référence en ondes sonores à l'origine d'au moins une partie des bruits à atténuer, cette acquisition étant réalisée directement par voie électromagnétique (par exemple, acquisition directe du signal électrique par voie filaire, acquisition en captant une onde, radio ou lumineuse, modulée en fonction du signal de référence, ou autres) au plus tard au moment où l'appareil électrique générateur de sons transforme ledit signal électrique de référence en ondes sonores, et en ce qu'on détermine les contrebruits en fonction de ce signal électrique de référence.The process described in this document is satisfactory, in particular for attenuating random noises such as those coming from the street, but it nevertheless has the disadvantage that the counter noises must be calculated and emitted extremely quickly before the noises to be attenuated reach the space to be soundproofed, which limits the volume of the calculations made to determine the noise abatements, and therefore the quality of the soundproofing. The object of the present invention is in particular to overcome this drawback, when the noises to be attenuated are emitted by an electric sound generating apparatus such as a radio, television receiver, a hi-fi system, or the like. To this end, according to the invention, a method of the kind in question is essentially characterized in that an electrical signal known as a reference signal, used read by an electrical sound generator which transforms this reference electrical signal into sound waves at the origin of at least part of the noise to be attenuated, this acquisition being carried out directly by electromagnetic means (for example, direct acquisition of the electrical signal by wire, acquisition by capturing a wave, radio or light, modulated as a function of the reference signal, or others) at the latest when the electric sound generating apparatus transforms said electric reference signal into sound waves, and what one determines the noises according to this electrical reference signal.
Grâce à ces dispositions, le signal qui sert à déterminer les contrebruits est acquis au plus tard lors de l'émission des bruits, alors que dans les procédés de l'art antérieur, ce signal était acquis par des transducteurs, par exemple des microphones, qu'après que les ondes sonores à l'origine des bruits aient déjà parcouru une certaine distance : l'invention évite ce retard dans 1 ' ac- quisition du signal de référence utilisé pour déterminer les contrebruits, ce qui permet de disposer de plus de temps pour déterminer lesdits contrebruits, et donc d'utiliser un processus d'élaboration desdits contrebruits qui soit plus fin et plus efficace que dans l'art ultérieur. Dans des modes de réalisation préférés du procédé selon l'invention, on peut éventuellement avoir recours en outre à l'une et/ou à l'autre des dispositions suivantes : les contrebruits sont émis au moyen d'un nombre n non nul de haut-parleurs, et on détermine les contre- bruits également en fonction de données relatives à la propagation des sons, d'une part, entre l'appareil électrique générateur de sons et l'espace à insonoriser, et d'autre part, entre les haut-parleurs et l'espace à insonoriser ; les contrebruits sont élaborés par filtrage adaptatif, - chaque haut-parleur i émet un signal s,(t) = ∑ - h,j(-t) ® gj(t) ® S(t) ,Thanks to these arrangements, the signal which is used to determine the noises is acquired at the latest when the noises are emitted, whereas in the methods of the prior art, this signal was acquired by transducers, for example microphones, that after the sound waves at the origin of the noises have already traveled a certain distance: the invention avoids this delay in acquiring the reference signal used to determine the noises, which makes it possible to have more time to determine said counter noises, and therefore to use a process for preparing said noises which is finer and more efficient than in the subsequent art. In preferred embodiments of the method according to the invention, it is optionally possible to have recourse to one and / or the other of the following arrangements: the counter-noises are emitted by means of a non-zero number n high -speakers, and the noise countermeasures are also determined as a function of data relating to the propagation of sounds, on the one hand, between the electrical sound generating apparatus and the space to be soundproofed, and on the other hand, between the loudspeakers and the space to be soundproofed; the counter-noises are worked out by adaptive filtering, - each loudspeaker i emits a signal s, (t) = ∑ - h, j (-t) ® gj (t) ® S (t),
J où : hι:,(-t) représente la retournée temporelle de la réponse impulsionnelle h1D (t) , préalablement déterminée et mémorisée, entre le haut-parleur i et un point j prédéterminé dit "de calibration" appartenant à l'espace à insonoriser, l'espace à insonoriser comprenant un nombre p non nul de points de calibration, la réponse impulsionnelle h1D(t) correspondant au signal acoustique reçu au point j lorsque le haut-parleur i émet une courte impulsion acoustique, gD(t) est la réponse impulsionnelle, préalablement déterminée et mémorisée, entre l'appareil électrique générateur de sons et le point de calibration j , cette réponse impulsionnelle g**(t) correspondant au signal acoustique reçu au point de calibration j lorsque l'appareil électrique générateur de sons émet une courte impulsion acoustique,J where: h ι:, (- t) represents the time feedback of the impulse response h 1D (t), previously determined and stored, between the speaker i and a predetermined point j called "calibration" belonging to the space to be soundproofed, the space to be soundproofed comprising a non-zero number p of calibration points, the impulse response h 1D (t) corresponding to the acoustic signal received at point j when the loudspeaker i emits a short acoustic pulse, g D (t) is the impulse response, previously determined and stored, between the sound-generating electrical apparatus and the calibration point j, this impulse response g ** (t) corresponding to the acoustic signal received at the calibration point j when the electric sound generator emits a short acoustic pulse,
S(t) est une estimation du signal acoustique émis par l'appareil électrique générateur de sons, cette estimation étant déterminée en fonction du signal électrique de référence, et <£> désigne le produit de convolution ;S (t) is an estimate of the acoustic signal emitted by the electric sound generating apparatus, this estimate being determined as a function of the reference electric signal, and <£> denotes the convolution product;
S(t) s'exprime sous la forme A.s(t), où A est un coefficient constant au moins par périodes et s(t) est un signal déterminé directement à partir du signal élec- trique de référence, et on mesure le bruit dans l'espace à insonoriser pour déterminer le coefficient A ; le coefficient A est déterminé par un processus de minimisation du bruit dans l'espace à insonoriser. Par ailleurs, l'invention a également pour objet un dispositif pour la mise en oeuvre d'un procédé tel que défini ci-dessus, ce dispositif comportant : un système d'acquisition par voie électromagnétique pour acquérir le signal électrique de référence, - une unité centrale électronique qui est reliée par voie électromagnétique (liaison radio, liaison filaire électrique, liaison par fibre optique, ou similaires) au système d'acquisition et qui est adaptée pour déterminer les contrebruits, - et un nombre n non nul de haut-parleurs qui sont reliés à l'unité centrale électronique pour émettre les contrebruits vers l'espace à insonoriser.S (t) is expressed in the form As (t), where A is a constant coefficient at least by periods and s (t) is a signal determined directly from the electric signal reference point, and the noise in the space to be soundproofed is measured to determine the coefficient A; the coefficient A is determined by a process of minimizing the noise in the space to be soundproofed. Furthermore, the subject of the invention is also a device for implementing a method as defined above, this device comprising: an electromagnetic acquisition system for acquiring the reference electrical signal, - a electronic central unit which is connected electromagnetically (radio link, electric wire link, fiber optic link, or the like) to the acquisition system and which is suitable for determining noise abatements, - and a non-zero number n of loudspeakers which are connected to the electronic central unit to emit the noise towards the space to be soundproofed.
Dans des modes de réalisation préférés du dispositif selon l'invention, on peut éventuellement avoir recours en outre à l'une et/ou à l'autre des dispositions suivantes : le dispositif comprend l'appareil électrique générateur de sons, et le dispositif d'acquisition est intégré à cet appareil électrique ; - l'appareil électrique générateur de sons est adapté pour générer les ondes sonores correspondant au signal électrique de référence avec un certain retard par rapport à l'acquisition dudit signal électrique de référence par le dispositif d'acquisition ; - ledit retard est compris entre 0,01 et 2 secondes ; l'appareil électrique générateur de sons génère également des images, avec le même retard que pour la génération desdites ondes sonores ; le dispositif d'acquisition est connecté à l'appareil électrique générateur de sons ; l'appareil électrique générateur de sons est un récepteur adapté pour recevoir ledit signal électrique de référence sur un canal de réception parmi un certain nombre de canaux de réception prédéterminés, le dispositif d'acquisition étant lui-même un récepteur qui est indépendant dudit appareil électrique générateur de sons et qui est adapté pour recevoir un signal électrique sur un canal de réception parmi lesdits canaux de réception prédéterminés, le dispositif comportant en outre des moyens pour sé- lectionner le canal de réception sur lequel est reçu le signal électrique de référence ; le dispositif comporte en outre au moins un microphone qui est adapté pour recevoir les bruits engendrés par l'appareil électrique générateur de sons, ce micro- phone étant relié à l'unité centrale pour lui transmettre un signal électrique représentatif des bruits reçus par ledit microphone, et ladite unité centrale étant adaptée pour : commander le dispositif de réception en lui fai- sant balayer les différents canaux de réception et en comparant les signaux électriques ainsi reçus avec le signal électrique provenant du microphone, sélectionner un canal de réception, sur lequel est reçu le signal électrique le plus proche du signal élec- trique provenant du microphone, et utiliser ensuite le signal électrique reçu sur ce canal de réception en tant que signal électrique de référence .In preferred embodiments of the device according to the invention, it is possible optionally to have recourse to one and / or the other of the following arrangements: the device comprises the electrical sound generating apparatus, and the device d acquisition is integrated into this electrical appliance; the electrical sound generator is adapted to generate the sound waves corresponding to the reference electrical signal with a certain delay with respect to the acquisition of said reference electrical signal by the acquisition device; - said delay is between 0.01 and 2 seconds; the sound generating electrical apparatus also generates images, with the same delay as for the generation of said sound waves; the acquisition device is connected to the electrical sound generator; the electrical sound generating apparatus is a receiver adapted to receive said reference electrical signal on a reception channel from a number of predetermined reception channels, the acquisition device itself being a receiver which is independent of said electrical apparatus sound generator and which is adapted to receive an electrical signal on a reception channel among said predetermined reception channels, the device further comprising means for selecting the reception channel on which the reference electrical signal is received; the device further comprises at least one microphone which is adapted to receive the noises generated by the electrical sound generating apparatus, this microphone being connected to the central unit to transmit to it an electrical signal representative of the noises received by said microphone , and said central unit being adapted for: controlling the reception device by making it scan the various reception channels and by comparing the electrical signals thus received with the electrical signal coming from the microphone, selecting a reception channel, on which is received the electrical signal closest to the electrical signal from the microphone, and then use the electrical signal received on this reception channel as the reference electrical signal.
D'autres caractéristiques et avantages de 1 ' înven- tion apparaîtront au cours de la description suivante d'une de ses formes de réalisation, donnée a titre d'exemple non limitatif, en regard des dessins joints. Sur les dessins : la figure 1 est une vue schématique illustrant un premier mode de réalisation de l'invention, la figure 2 est une vue schématique de l'appareil électrique générateur de sons dont on cherche a atténuer le bruit, dans un deuxième mode de réalisation de 1 ' invention, - et la figure 3 est une vue schématique similaire a la figure 1, illustrant un troisième mode de réalisation de l'invention.Other characteristics and advantages of the invention will appear during the following description of one of its embodiments, given by way of nonlimiting example, with reference to the accompanying drawings. In the drawings: FIG. 1 is a diagrammatic view illustrating a first embodiment of the invention, FIG. 2 is a diagrammatic view of the electrical sound generator apparatus for which noise is sought to be reduced, in a second embodiment embodiment of the invention, and FIG. 3 is a schematic view similar to FIG. 1, illustrating a third embodiment of the invention.
Sur les différentes figures, les mêmes références désignent des éléments identiques ou similaires. Dans l'exemple représenté sur la figure 1, on cherche à insonoriser un espace 1, formant une certaine zone d'un local 2 appartenant à un bâtiment 3, en atténuant les bruits engendrés par un appareil électrique générateur de sons 4. Dans l'exemple considéré ici, l'appareil électrique générateur de sons est un récepteur de télévision, mais il pourrait s'agir de tout autre appareil électrique qui transforme un signal électrique analogique ou numérique, dit signal électrique de référence, en ondes sonores à l'origine d'au moins une partie des bruits que l'on cherche à atténuer dans l'espace 1. Ainsi, l'appareil électrique générateur de sons pourrait être également constitué par un récepteur de radio, un lecteur de disque optique, un lecteur de disque à microsillons, un lecteur de bande magnétique (présentée ou non sous forme de cassette) , un haut parleur recevant par voie filaire ou autre le signal à diffuser, etc, ou une combinaison de ces éléments.In the different figures, the same references designate identical or similar elements. In the example shown in Figure 1, we seek to soundproof a space 1, forming a certain area of a room 2 belonging to a building 3, by reducing the noise generated by an electrical sound generator 4. In the example considered here, the electrical sound generating device is a television receiver, but it could be any other electrical device which transforms an analog or digital electrical signal, known as the reference electrical signal, into sound waves at the origin at least some of the noise that we are trying to reduce in space 1. Thus, the electrical sound generating device could also be constituted by a radio receiver, an optical disc player, a microgroove disc player, a magnetic tape player (presented or not in the form of a cassette), a loudspeaker receiving by wire or other means the signal to be broadcast, etc., or a combination of these.
L'appareil électrique générateur de sons dont on cherche à atténuer les bruits est en général situé dans un autre local 5 du même bâtiment 3 que l'espace 1, mais cet appareil pourrait également être situé à l'extérieur du bâtiment 3, par exemple lorsqu'on cherche à atténuer les bruits provenant d'une sonorisation de rue ou d'une sonorisation de concert en plein air. De la même façon, l'espace 1 à insonoriser pourrait le cas échéant être situé à l'extérieur d'un bâtiment .The electrical sound generating appliance whose noise is sought to be attenuated is generally located in another room 5 of the same building 3 as space 1, but this appliance could also be located outside of building 3, for example when trying to attenuate the noises coming from a street sound system or an outdoor concert sound system. Similarly, the space 1 to be soundproofed could if necessary be located outside a building.
L'insonorisation de l'espace 1 est réalisée en générant dans cet espace des contrebruits, en opposition de phase avec les bruits provenant de l'appareil électrique 4 générateur de sons.The soundproofing of the space 1 is carried out by generating in this space counter-noise, in phase opposition with the noise coming from the electrical apparatus 4 generating sounds.
Ces contrebruits sont générés par un nombre n, au moins égal à 1 et généralement au moins égal à 2, de haut- parleurs 6 commandés par une unité centrale électronique 7, qui est généralement constituée par un calculateur relié par voie filaire ou hertzienne aux haut-parleurs 6 par l'intermédiaire de convertisseurs analogiques-numériques intégrés par exemple dans ledit calculateur.These noises are generated by a number n, at least equal to 1 and generally at least equal to 2, of loudspeakers 6 controlled by an electronic central unit 7, which generally consists of a computer connected by wire or wireless to the high -speakers 6 by means of analog-digital converters integrated for example into said computer.
Par ailleurs, le calculateur 7 est également relié par voie électromagnétique à l'appareil électrique générateur de son 4, de façon à recevoir de cet appareil le signal électrique de référence susmentionné. Cette liaison électromagnétique peut être réalisée par voie filaire (liaison point à point ou bus domotique, par câble plein, par câble coaxial ou par fibre optique) ou par voie hertzienne, comme dans l'exemple représenté sur la figure 1.Furthermore, the computer 7 is also connected electromagnetically to the sound generating electrical device 4, so as to receive from this device the above-mentioned reference electrical signal. This electromagnetic link can be made by wire (point-to-point link or home automation bus, by solid cable, by coaxial cable or by optical fiber) or by radio, as in the example shown in FIG. 1.
Dans ce dernier cas, le calculateur 7 est relié à un récepteur radio 8 tandis qu'un émetteur radio 9 est connecté au téléviseur 4, par exemple par l'intermédiaire de la sortie audio ou de la prise "Péritel" de ce télévi- seur ou de tout autre interface, pour transmettre le signal électrique de référence vers le récepteur 8 et le calculateur 7.In the latter case, the computer 7 is connected to a radio receiver 8 while a radio transmitter 9 is connected to the television 4, for example by means of the audio output or the "Scart" socket of this television. or any other interface, for transmitting the reference electrical signal to the receiver 8 and the computer 7.
Compte tenu du fait que l'acquisition et la transmission du signal électrique de référence par voie élec- tromagnétique est quasi instantanée en comparaison de la propagation du son, le calculateur 7 connaît ainsi le signal de référence s(t) correspondant au signal sonore émis par l'appareil électrique générateur de sons 4, bien avant que ce signal sonore n'atteigne le local 2. Le calculateur 7 dispose ainsi du maximum de temps pour évaluer de façon optimale les contrebruits à faire émettre par les différents haut-parleurs 6.Given the fact that the acquisition and transmission of the reference electrical signal by electromagnetic means is almost instantaneous in comparison with the propagation of the sound, the computer 7 thus knows the reference signal s (t) corresponding to the emitted sound signal by the electric sound generator 4, well before this sound signal reaches room 2. The computer 7 thus has maximum time to optimally assess the noise to be emitted by the various speakers 6.
Cette détermination des contrebruits peut être réalisée par tout moyen connu, par exemple par filtrage adaptatif par exemple comme enseigné dans le document EP- A-0 505 949 (voir la figure 16 de ce document, où le signal s(t) serait appliqué au circuit à la place du signal provenant du microphone 25 de ladite figure 16) , ou selon un procédé voisin du procédé enseigné dans le document EP- A-0 601 934. ^This determination of the noises can be carried out by any known means, for example by adaptive filtering for example as taught in the document EP-A-0 505 949 (see FIG. 16 of this document, where the signal s (t) would be applied to the circuit in place of the signal from the microphone 25 of said FIG. 16), or according to a method similar to the method taught in document EP-A-0 601 934. ^
Dans ce cas, au cours d'une étape initiale de calibration, on mesure au niveau d'un nombre p (généralement supérieur à 2) de points dits "de calibration" 10 de l'espace 1 : d'une part, la réponse impulsionnelle h (t) , entre chaque haut-parleur 6 d'indice i et chaque point de calibration 10 d'indice j, la réponse impulsionnelle h1D(t) correspondant au signal acoustique reçu au point j lorsque le haut-parleur i émet une courte impulsion acoustique, et la réponse impulsionnelle g-, (t) entre 1 ' ap- pareil électrique générateur de sons 4 et chaque point de calibration j, cette réponse impulsionnelle correspondant au signal acoustique reçu au point j lorsque l'appareil électrique générateur de sons émet une courte impulsion acoustique, ou lorsqu'un appareil spécial émet ladite courte impulsion acoustique depuis l'emplacement de l'appareil électrique 4.In this case, during an initial calibration step, we measure at the level of a number p (generally greater than 2) of so-called "calibration" points 10 in space 1: on the one hand, the impulse response h (t), between each loudspeaker 6 of index i and each calibration point 10 of index j, the impulse response h 1D (t) corresponding to the acoustic signal received at point j when the loudspeaker i emits a short acoustic impulse, and the impulse response g-, (t) between the electrical sound generating apparatus 4 and each calibration point j, this impulse response corresponding to the acoustic signal received at point j when the electrical sound-generating device emits a short acoustic pulse, or when a special device emits said short acoustic pulse from the location of the electrical appliance 4.
Les réponses impulsionnelles hι;)(t) et g-- (t) peuvent être mesurées par exemple en disposant un microphone 11 successivement aux différents points de calibration 10 (ou en disposant plusieurs microphones simultanément aux différents points 10) et en faisant émettre les impulsions acoustiques susmentionnées par les haut-parleurs 6, et depuis l'emplacement de l'appareil électrique générateur de son 4, ce microphone 11 étant relié au calculateur 7 par voie filaire ou hertzienne, par l'intermédiaire d'un convertisseur analogique-digital intégré audit calculateur de façon que les réponses impulsionnelles puissent être acquises et mémorisées par le calculateur 7.The impulse responses h ι;) (t) and g-- (t) can be measured for example by placing a microphone 11 successively at the different calibration points 10 (or by placing several microphones simultaneously at the different points 10) and by transmitting the aforementioned acoustic pulses by the loudspeakers 6, and from the location of the electric sound generating apparatus 4, this microphone 11 being connected to the computer 7 by wire or wireless, by means of an analog converter- digital integrated into said computer so that the impulse responses can be acquired and stored by the computer 7.
Pour insonoriser l'espace 1, le calculateur 7 fait ensuite émettre par chaque haut-parleur i un signal
Figure imgf000011_0001
où : hι;)(-t) représente la retournée temporelle de la réponse impulsionnelle h1D(t),To soundproof the space 1, the computer 7 then sends a signal from each speaker i
Figure imgf000011_0001
where: h ι;) (-t) represents the time return of the impulse response h 1D (t),
S(t) est une estimation du signal acoustique émis par l'appareil électrique générateur de sons, cette estimation étant déterminée en fonction du signal électrique de référence s(t), et ® désigne le produit de convolution. On rappelle ici que le produit de convolution d'une fonction f(t) par une fonction g(t) vaut :S (t) is an estimate of the acoustic signal emitted by the sound-generating electrical device, this estimate being determined as a function of the reference electrical signal s (t), and ® denotes the convolution product. We recall here that the convolution product of a function f (t) by a function g (t) is worth:
f{t) ® g{t) = ]f{τ)g{t - τ)dτf {t) ® g {t) =] f {τ) g {t - τ) dτ
De préférence, pour estimer le signal acoustique émis par l'appareil électrique générateur de son 4, le calculateur exprime cette estimation sous la forme S(t)=A.s(t), où A est un coefficient constant au moins par périodes, qui reflète le réglage du volume sonore effectué par l'utilisateur de l'appareil électrique 4.Preferably, to estimate the acoustic signal emitted by the electric sound generating apparatus 4, the computer expresses this estimate in the form S (t) = As (t), where A is a constant coefficient at least per period, which reflects the adjustment of the sound volume carried out by the user of the electrical appliance 4.
Afin d'évaluer le coefficient A, on peut par exemple laisser le microphone 11 (ou plusieurs microphones) en permanence dans l'espace 1 à insonoriser, et le calculateur 7 fait varier progressivement le coefficient A de façon à minimiser le bruit perçu par ledit microphone.In order to evaluate the coefficient A, it is possible for example to leave the microphone 11 (or more microphones) permanently in the space 1 to be soundproofed, and the computer 7 gradually varies the coefficient A so as to minimize the noise perceived by said microphone.
Ce processus de minimisation peut être mis en œuvre en permanence ou à intervalles de temps rapprochés par le calculateur 7, ou encore lorsque le microphone 11 mesure un niveau de bruit supérieur à un seuil déterminé, pour le cas où l'utilisation de l'appareil 4 aurait modifié le volume sonore de cet appareil. Le cas échéant, le coefficient A (ou l'estimation S(t)) pourrait être transmis par l'émetteur 9 à partir de données acquises directement dans l'appareil 4.This minimization process can be implemented continuously or at close time intervals by the computer 7, or even when the microphone 11 measures a noise level above a determined threshold, in the case where the use of the device 4 would have changed the volume of this device. If necessary, the coefficient A (or the estimate S (t)) could be transmitted by the transmitter 9 from data acquired directly in the device 4.
Par ailleurs, dans un deuxième mode de réalisation de l'invention, représenté sur la figure 2, l'émetteur radio 9', ou tout autre dispositif d'acquisition du signal électrique de référence s(t), pourrait être intégré à l'appareil électrique générateur de sons 4 qui ferait alors partie intégrante du dispositif d'insonorisation ac- tive selon l'invention.Furthermore, in a second embodiment of the invention, represented in FIG. 2, the radio transmitter 9 ′, or any other device for acquiring the reference electrical signal s (t), could be integrated into the electric sound generator 4 which would then be an integral part of the active soundproofing device according to the invention.
Dans ce cas, avantageusement, l'appareil électrique générateur de sons 4 peut être adapté pour générer les ondes sonores correspondant au signal électrique de référence avec un certain retard par rapport à l'acquisition dudit signal par l'émetteur 9, ce retard pouvant être compris par exemple entre 0,01 et 2 secondes : on peut ainsi donner du temps supplémentaire au calculateur 7 pour déterminer de façon optimale les contrebruits à faire émettre par les différents haut-parleurs 6. Lorsque l'appareil 4 génère également des images, comme dans le cas d'un récepteur de télévision, il génère ces images avec le même retard que pour les ondes sonores.In this case, advantageously, the electrical sound generator 4 can be adapted to generate the sound waves corresponding to the reference electrical signal with a certain delay with respect to the acquisition of said signal by the transmitter 9, this delay possibly being for example between 0.01 and 2 seconds: it is thus possible to give additional time to the computer 7 to optimally determine the noise to be emitted by the different speakers 6. When the device 4 also generates images, such as in the case of a television receiver, it generates these images with the same delay as for sound waves.
Enfin, selon un troisième mode de réalisation de l'invention, représenté sur la figure 3, lorsque l'appa- reil électrique générateur de sons 4 est un récepteur de radio ou de télévision, ou plus généralement tout appareil adapté pour recevoir le signal électrique de référence s(t) sur un canal de réception parmi un certain nombre de canaux de réception prédéterminés, on peut éventuellement éviter de connecter ou d'intégrer à cet appareil 4 un dispositif spécial d'acquisition du signal électrique de référence . A cet effet, on utilise un dispositif d'acquisition 12 constitué par un récepteur qui est indépendant du récepteur 4 et qui est relié au calculateur 7.Finally, according to a third embodiment of the invention, shown in FIG. 3, when the electrical sound generator 4 is a radio or television receiver, or more generally any device adapted to receive the electrical signal reference s (t) on a reception channel among a certain number of predetermined reception channels, it is possibly possible to avoid connecting or integrating with this apparatus 4 a special device for acquiring the reference electric signal. To this end, an acquisition device 12 is used, consisting of a receiver which is independent of the receiver 4 and which is connected to the computer 7.
Ce récepteur 12 est similaire au récepteur 4, et il est adapté pour recevoir des signaux électriques sur les mêmes canaux de réception que le récepteur 4.This receiver 12 is similar to the receiver 4, and it is adapted to receive electrical signals on the same reception channels as the receiver 4.
Le récepteur 12 peut par exemple être piloté par le calculateur 7, de façon à balayer les différents canaux de réception, le calculateur 7 comparant alors les signaux électriques ainsi reçus avec les signaux électriques provenant du microphone 11.The receiver 12 can for example be controlled by the computer 7, so as to scan the various reception channels, the computer 7 then comparing the electrical signals thus received with the electrical signals coming from the microphone 11.
En comparant ces différents signaux électriques, le calculateur 7 peut sélectionner un canal de réception, sur lequel est reçu le signal électrique le plus proche du signal provenant du microphone, le signal électrique s(t) reçu sur ce canal de réception étant ensuite utilisé par le calculateur 7 en tant que signal électrique de référence.By comparing these different electrical signals, the computer 7 can select a reception channel, on which the electrical signal closest to the signal from the microphone is received, the electrical signal s (t) received on this reception channel being then used by the computer 7 as an electrical reference signal.
Ce processus peut être mis en œuvre à intervalles de temps réguliers par le calculateur 7, ou lorsque le niveau de bruit mesuré par le microphone 11 dépasse un certain seuil, pour le cas où l'utilisateur du récepteur 4 aurait changé de canal de réception.This process can be implemented at regular time intervals by the computer 7, or when the noise level measured by the microphone 11 exceeds a certain threshold, in the case where the user of the receiver 4 has changed the reception channel.
Enfin, on notera que les contrebruits émis selon l'invention pourraient être superposés à des contrebruits calculés selon l'art antérieur à partir de mesures effectuées par des microphones situés à l'intérieur de l'espace 1, pour atténuer les bruits autres que ceux générés par l'appareil électrique générateur de sons 4. Finally, it will be noted that the noise emitted according to the invention could be superimposed on the noise calculated according to the prior art from measurements made by microphones located inside the space 1, to attenuate the noises other than those generated by the electrical sound generator 4.

Claims

REVENDICATIONS
1. Procédé pour insonoriser un espace (1) recevant des bruits, en émettant des contrebruits dans ledit es- pace, caractérisé en ce qu'on acquiert un signal électrique dit de référence, utilisé par un appareil électrique générateur de sons (4) qui transforme ce signal électrique de référence en ondes sonores à l'origine d'au moins une par- tie des bruits à atténuer, cette acquisition étant réalisée directement par voie électromagnétique au plus tard au moment où l'appareil électrique générateur de sons (4) transforme ledit signal électrique de référence en ondes sonores, et en ce qu'on détermine les contrebruits en fonction de ce signal électrique de référence.1. Method for soundproofing a space (1) receiving noise, by emitting noise in said space, characterized in that an electrical signal called reference is acquired, used by an electric sound generating device (4) which transforms this reference electrical signal into sound waves at the origin of at least part of the noise to be attenuated, this acquisition being carried out directly by electromagnetic means at the latest when the electric sound generating apparatus (4) transforms said reference electrical signal into sound waves, and in that the noise counterparts are determined as a function of this reference electrical signal.
2. Procédé selon la revendication 1, dans lequel les contrebruits sont émis au moyen d'un nombre n non nul de haut-parleurs (6) , et on détermine les contrebruits également en fonction de données relatives à la propagation des sons, d'une part, entre l'appareil électrique générateur de sons (4) et l'espace à insonoriser, et d'autre part, entre les haut-parleurs (6) et l'espace à insonoriser ( 1) . 2. Method according to claim 1, in which the noise is emitted by means of a non-zero number n of loudspeakers (6), and the noise is also determined as a function of data relating to the propagation of sounds, on the one hand, between the electric sound generating device (4) and the space to be soundproofed, and on the other hand, between the speakers (6) and the space to be soundproofed (1).
3. Procédé selon la revendication 2, dans lequel les contrebruits sont élaborés par filtrage adaptatif.3. The method of claim 2, wherein the noise is produced by adaptive filtering.
4. Procédé selon la revendication 2, dans lequel chaque haut-parleur i émet un signal4. Method according to claim 2, in which each speaker i emits a signal.
Λ(0 = ∑ J-Λ..(-0®g(0®S(θ, où : hij(-t) représente la retournée temporelle de la réponse impulsionnelle h13(t), préalablement déterminée et mémorisée, entre le haut-parleur i et un point j prédéterminé dit "de calibration" appartenant à l'espace à in- sonoriser, l'espace à insonoriser comprenant un nombre p non nul de points de calibration (10), la réponse impulsionnelle hX](t) correspondant au signal acoustique reçu au point j lorsque le haut-parleur i émet une courte impulsion acoustique, - g-j(t) est la réponse impulsionnelle, préalablement déterminée et mémorisée, entre l'appareil électrique générateur de sons (4) et le point de calibration j, cette réponse impulsionnelle g*-(t) correspondant au signal acoustique reçu au point de calibration j lorsque 1 ' appa- reil électrique générateur de sons émet une courte impulsion acoustique, Λ (0 = Σ J-Λ (-0®g (0®S (θ, where..: hi j (-t) represents the time feedback of the impulse response h 13 (t), previously determined and stored, between the loudspeaker i and a predetermined point j called "calibration" belonging to the space to be soundproofed , the space to be soundproofed comprising a non-zero number p of calibration points (10), the impulse response h X] (t) corresponding to the acoustic signal received at point j when the loudspeaker i emits a short acoustic pulse, - g- j (t) is the impulse response, previously determined and stored, between the electrical sound generator (4) and the calibration point j, this impulse response g * - (t) corresponding to the acoustic signal received at the point calibration j when the electric sound generator emits a short acoustic pulse,
S(t) est une estimation du signal acoustique émis par l'appareil électrique générateur de sons (4), cette estimation étant déterminée en fonction du signal électrique de référence et <8> désigne le produit de convolution.S (t) is an estimate of the acoustic signal emitted by the electric sound generator (4), this estimate being determined as a function of the reference electric signal and <8> denotes the convolution product.
5. Procédé selon la revendication 4, dans lequel S(t) s'exprime sous la forme A.s(t), où A est un coefficient constant au moins par périodes et s(t) est un signal déterminé directement à partir du signal électrique de référence, et on mesure le bruit dans l'espace à insonoriser (1) pour déterminer le coefficient A.5. Method according to claim 4, in which S (t) is expressed in the form As (t), where A is a constant coefficient at least by periods and s (t) is a signal determined directly from the electrical signal of reference, and the noise in the space to be soundproofed (1) is measured to determine the coefficient A.
6. Procédé selon la revendication 5, dans lequel le coefficient A est déterminé par un processus de minimi- sation du bruit dans l'espace à insonoriser (1). 6. Method according to claim 5, in which the coefficient A is determined by a noise minimization process in the space to be soundproofed (1).
7. Dispositif pour la mise en oeuvre d'un procédé selon l'une quelconque des revendications 1 à 6, ce dispositif comportant : un système d'acquisition (9, 9', 12) par voie électromagnétique pour acquérir le signal électrique de référence, une unité centrale électronique (7) qui est reliée par voie électromagnétique au système d'acquisition (9, 9', 12) et qui est adaptée pour déterminer les contre- bruits, et un nombre n non nul de haut-parleurs (6) qui sont reliés à l'unité centrale électronique (7) pour émettre les contrebruits vers l'espace à insonoriser (1).7. Device for implementing a method according to any one of claims 1 to 6, this device comprising: an acquisition system (9, 9 ', 12) by electromagnetic means for acquiring the reference electrical signal , an electronic central unit (7) which is electromagnetically connected to the acquisition system (9, 9 ', 12) and which is adapted to determine the noise abatements, and a non-zero number n of loudspeakers (6 ) which are connected to the electronic central unit (7) to emit the noise towards the space to be soundproofed (1).
8. Dispositif selon la revendication 7, dans le- quel le dispositif comprend l'appareil électrique générateur de sons (4), et le dispositif d'acquisition (9') est intégré à cet appareil électrique.8. Device according to claim 7, in which the device comprises the electrical sound generating apparatus (4), and the acquisition device (9 ') is integrated into this electrical apparatus.
9. Dispositif selon la revendication 8, dans lequel l'appareil électrique générateur de sons (4) est adapté pour générer les ondes sonores correspondant au signal électrique de référence avec un certain retard par rapport à l'acquisition dudit signal électrique de référence par le dispositif d'acquisition (9').9. Device according to claim 8, in which the electrical sound generating apparatus (4) is adapted to generate the sound waves corresponding to the reference electrical signal with a certain delay with respect to the acquisition of said reference electrical signal by the acquisition device (9 ').
10. Dispositif selon la revendication 9, dans le- quel ledit retard est compris entre 0,01 et 2 secondes.10. Device according to claim 9, in which said delay is between 0.01 and 2 seconds.
11. Dispositif selon l'une quelconque des revendications 9 ou 10, dans lequel l'appareil électrique générateur de sons (4) génère également des images, avec le même retard que pour la génération desdites ondes sonores. 11. Device according to any one of claims 9 or 10, in which the electrical sound generator (4) also generates images, with the same delay as for the generation of said sound waves.
12. Dispositif selon la revendication 7, dans lequel le dispositif d'acquisition (9) est connecté à l'appareil électrique générateur de sons. 12. Device according to claim 7, in which the acquisition device (9) is connected to the electrical sound generator.
13. Dispositif selon la revendication 7, dans lequel l'appareil électrique générateur de sons (4) est un récepteur adapté pour recevoir ledit signal électrique de référence sur un canal de réception parmi un certain nom- bre de canaux de réception prédéterminés, le dispositif d'acquisition (12) étant lui-même un récepteur qui est indépendant dudit appareil électrique générateur de sons (4) et qui est adapté pour recevoir un signal électrique sur un canal de réception parmi lesdits canaux de réception prédéterminés, le dispositif comportant en outre des moyens (7) pour sélectionner le canal de réception sur lequel est reçu le signal électrique de référence.13. Device according to claim 7, in which the electrical sound generating apparatus (4) is a receiver adapted to receive said reference electrical signal on a reception channel among a certain number of predetermined reception channels, the device acquisition device (12) itself being a receiver which is independent of said electrical sound generating apparatus (4) and which is adapted to receive an electrical signal on a reception channel among said predetermined reception channels, the device further comprising means (7) for selecting the reception channel on which the reference electrical signal is received.
14. Dispositif selon la revendication 13, dans lequel le dispositif comporte en outre au moins un micro- phone (11) qui est adapté pour recevoir les bruits engendrés par l'appareil électrique générateur de sons, ce microphone étant relié à l'unité centrale (7) pour lui transmettre un signal électrique représentatif des bruits reçus par ledit microphone, et ladite unité centrale étant adaptée pour : commander le dispositif de réception (12) en lui faisant balayer les différents canaux de réception et en comparant les signaux électriques ainsi reçus avec le signal électrique provenant du microphone, - sélectionner un canal de réception, sur lequel est reçu le signal électrique le plus proche du signal électrique provenant du microphone (11), et utiliser ensuite le signal électrique reçu sur ce canal de réception en tant que signal électrique de référence. 14. Device according to claim 13, in which the device further comprises at least one microphone (11) which is adapted to receive the noises generated by the electric sound generating apparatus, this microphone being connected to the central unit. (7) for transmitting to it an electrical signal representative of the noises received by said microphone, and said central unit being adapted for: controlling the reception device (12) by making it scan the various reception channels and by comparing the electrical signals thus received with the electrical signal from the microphone, - select a reception channel, on which the electrical signal closest to the electrical signal from the microphone (11) is received, and then use the electrical signal received on this reception channel as electrical reference signal.
PCT/FR1998/002468 1997-11-21 1998-11-19 Active soundproofing method and device WO1999027520A1 (en)

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EP98955694A EP1032932A1 (en) 1997-11-21 1998-11-19 Active soundproofing method and device
AU12446/99A AU1244699A (en) 1997-11-21 1998-11-19 Active soundproofing method and device
JP2000522581A JP2001524701A (en) 1997-11-21 1998-11-19 Active silencing method and device

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FR9714653A FR2771541B1 (en) 1997-11-21 1997-11-21 ACTIVE SOUNDPROOFING METHOD AND DEVICE
FR97/14653 1997-11-21

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FR2771541B1 (en) 2000-10-20
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EP1032932A1 (en) 2000-09-06
FR2771541A1 (en) 1999-05-28

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