Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Thomas Roeder

Thomas Sporer

Sandra Brix

Frank Melchior

Katrin Reichelt

Gabriel Gatzsche

Michael Beckinger

Michael Strauss

Martin Dausel

Joachim Deguara

Renè Rodigast

Jan Langhammer

In a reproduction area where there are at least three directional groups, each of which has speakers, triggering of the speakers is achieved in that a source path from a first directional group position to a second directional group position is initially obtained along with movement information for the source path. Subsequently, a source path parameter is calculated for different points in time on the basis of the movement information, the source path parameter indicating a position of an audio source on the source path. In addition, a path modification command is received to define a compensation path to the third directional zone, a value of the source path parameter further being stored at a location where the compensation path deviates from the source path, and being used, along with a compensation parameter, for calculating weighting factors for the speakers of the three directional groups.

Apparatus and method for controlling a plurality of speakers by means of a graphical user interface

In a reproduction environment, speakers are grouped in directional groups, wherein the directional groups overlap with respect to the associated speakers so that speakers are present which have a speaker parameter having different values for the first directional group and the second directional group. A controller for controlling a plurality of speakers has a provider for providing a source position of an audio source, wherein the source position is located between the first directional group position and the second directional group position. The apparatus further has a calculator for calculating a speaker signal for the at least one speaker, based on the first parameter value for the speaker parameter and based on the second parameter value for the speaker parameter.

Apparatus and method for controlling a plurality of speakers by means of a DSP

For a level correction in a wave field synthesis system having a wave field synthesis module and an array of loudspeakers for providing sound to a presentation region, a correction value which is based on a set amplitude state in a presentation region is determined, the set amplitude state depending on a position of the virtual source or a type of the virtual source, and the actual amplitude state in the presentation region depending on the component signals for the loudspeakers due to the virtual source. The correction value determined is fed to a manipulator manipulating the audio signal associated to the virtual source before feeding to the wave field synthesis module, or the component signals for the individual loudspeakers due to the virtual source are manipulated to reduce a deviation between a set amplitude state and an actual amplitude state at one point or several in the presentation region.

Device for level correction in a wave field synthesis system

For reducing Doppler artifacts in the wave-field synthesis due to delay changes from one time to a second time, first, the delay for the first time and the delay for the second time are determined. Then, a value of an audio signal delayed by the first delay for the current time and the value for the audio signal delayed by the second delay for the current time are determined. Then, the first value is weighted by a first weighting factor and a second value is averaged with a second weighting factor, whereupon the two weighted values are added up to obtain a discrete value for the current time of the component in a loudspeaker signal for a loudspeaker based on a virtual source. Thus, by knowing a delay present at a later time, panning is obtained from a delay to a subsequent delay, which reduces undesired Doppler artifacts.

Calculating a doppler compensation value for a loudspeaker signal in a wavefield synthesis system

In a wave field synthesis apparatus for driving an array of loudspeakers with drive signals, the loudspeakers being arranged at different defined positions, a drive signal for a loudspeaker being based on an audio signal associated with a virtual source having a virtual position with reference to the loudspeaker array and on the defined position of the loudspeaker, at first relevant loudspeakers of the loudspeaker array are determined on the basis of the position of the virtual source, a predefined listener position, and the defined positions of the loudspeakers, so that artifacts due to loudspeaker signals moving opposite to a direction from the virtual source to the predefined listener position are reduced. Downstream to means for calculating the drive signal components for the relevant loudspeakers and for a virtual source, there is means for providing the drive signal components for the relevant loudspeakers for the virtual source to the relevant loudspeakers, wherein no drive signals for the virtual source are provided to loudspeakers of the loudspeaker array not belonging to the relevant loudspeakers. With this, artifacts in an area of the audience room due to a generation wave field are suppressed, so that in this area only the useful wave field is heard in artifact-free manner.

Wave field synthesis apparatus and method of driving an array of loudspeakers

An apparatus for generating, storing or editing an audio representation of an audio scene includes audio processing means for generating a plurality of speaker signals from a plurality of input channels as well as means for providing an object-oriented description of the audio scene, wherein the object-oriented description of the audio scene includes a plurality of audio objects, wherein an audio object is associated with an audio signal, a starting time instant and an end time instant. The apparatus for generating further distinguishes itself by mapping means for mapping the object-oriented description of the audio scene to the plurality of input channels, wherein an assignment of temporally overlapping audio objects to parallel input channels is performed by the mapping means, whereas temporally sequential audio objects are associated with the same channel. With this, an object-oriented representation is transferred into a channel-oriented representation, whereby on the object-oriented side the optimal representation of a scene may be used, whereas on channel-oriented side the channel-oriented concept users are used to may be maintained.

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Elxleben, Germany

Thomas Roeder