Abstract: A method of controlling a sound field reproduction unit (2) having numerous reproduction elements (3n), uses a plurality of sound information input signals (SI) which are each associated with a general pre-determined reproduction direction which is defined in relation to a given point (5). The method includes: determining parameters which are representative of the position of the elements (3n) in the three spatial dimensions; determining matching filters (A) from the spatial characteristics and the general pre-determined reproduction directions; determining control signals by applying the aforementioned filters to the sound information input signals (SI); and delivering control signals for application to the above-mentioned reproduction elements (3n).

Abstract: A method of processing a sound field representation which can be used to provide a representation which has been modified by at least spatial processing. The method includes: the establishment of an initial representation of the sound field and the establishment of a representation which has been modified by filtering combinations corresponding to the processing operation. The method also includes a step which defines the processing operation and which includes: a step involving the establishment of a set of directivity functions, which is representative of the processing and which takes the form of a set of coefficients corresponding to the spherical harmonic decomposition of the functions; and a step in which the filtering combinations are determined from the decomposition so that another step involving the application of the defined filtering combinations can be performed.

Abstract: This system for determining a representation of an acoustic field (P) includes: acoustic wave acquisition elements (1) including a plurality of elemental sensors (21 to 2Q) which are distributed in space and which each deliver a measurement signal (c1 to cQ); and elements (8) for processing by the application, to the measurement signals (c1 to cQ), of filtering combinations representative of structural characteristics of the acquisition elements (1) in order to deliver a plurality of acoustic signals (sc1 to scN) which are each associated with a predetermined general reproduction direction defined relative to a given point in space (14), the set of acoustic signals (sc1 to scN) forming a representation of the acoustic field (P). The system is characterized in that the elemental sensors (21 to 2Q) are distributed in space in a substantially non-regular manner and in that the filtering combinations are representative of that distribution.

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

Abstract: A method of representing a sound field includes the steps of acquiring measurement signals (cn) which are delivered by simple sensors (2n) that are exposed to sound field (P) determining encoding filters which are representative of at least the structural characteristics of the sensors and processing the measurement signals (cn) by applying the encoding filters to the signals (cn), in order to determine a finite number of representative coefficients over time and in the three-dimensional space of the sound field (P).

Abstract: This system for determining a representation of an acoustic field (P) includes: acoustic wave acquisition elements (1) including a plurality of elemental sensors (21 to 2Q) which are distributed in space and which each deliver a measurement signal (c1 to cQ); and elements (8) for processing by the application, to the measurement signals (c1 to cQ), of filtering combinations representative of structural characteristics of the acquisition elements (1) in order to deliver a plurality of acoustic signals (sc1 to scN) which are each associated with a predetermined general reproduction direction defined relative to a given point in space (14), the set of acoustic signals (sc1 to scN) forming a representation of the acoustic field (P). The system is characterized in that the elemental sensors (21 to 2Q) are distributed in space in a substantially non-regular manner and in that the filtering combinations are representative of that distribution.

Abstract: A method of controlling a sound field reproduction unit (2) having numerous reproduction elements (3n), uses a plurality of sound information input signals (SI) which are each associated with a general pre-determined reproduction direction which is defined in relation to a given point (5). The method includes: determining parameters which are representative of the position of the elements (3n) in the three spatial dimensions; determining matching filters (A) from the spatial characteristics and the general pre-determined reproduction directions; determining control signals by applying the aforementioned filters to the sound information input signals (SI); and delivering control signals for application to the above-mentioned reproduction elements (3n).

Abstract: A method of processing a sound field representation which can be used to provide a representation which has been modified by at least spatial processing. The method includes: the establishment of an initial representation of the sound field and the establishment of a representation which has been modified by filtering combinations corresponding to the processing operation. The method also includes a step which defines the processing operation and which includes: a step involving the establishment of a set of directivity functions, which is representative of the processing and which takes the form of a set of coefficients corresponding to the spherical harmonic decomposition of the functions; and a step in which the filtering combinations are determined from the decomposition so that another step involving the application of the defined filtering combinations can be performed.

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

Abstract: The invention relates to a method of representing a sound field. The inventive method includes a step involving the acquisition of measurement signals (cn) which are delivered by acquisition means (1) comprising one or more simple sensors (2n) that are exposed to said sound field (P). The invention is characterised in that it comprises: a step involving the determination of encoding filters which are representative of at least the structural characteristics of the aforementioned acquisition means (1); and a step whereby the measurement signals (cn) are processed by applying said encoding filters to the signals (cn), in order to determine a finite number of representative coefficients over time and in the three-dimensional space of the sound field (P), said coefficients being used to produce a representation of the sound field (P) which is essentially independent of the characteristics of the acquisition means (1).