Device and method for decorrelating loudspeaker signals

Patent metadata

Field	Value
Publication number	US-9807534-B2
Application number	US-201615067466-A
Country	US
Kind code	B2
Filing date	Mar 11, 2016
Priority date	Sep 11, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A device for generating a multitude of loudspeaker signals based on a virtual source object which has a source signal and a meta information determining a position or type of the virtual source object. The device has a modifier configured to time-varyingly modify the meta information. In addition, the device has a renderer configured to transfer the virtual source object and the modified meta information to form a multitude of loudspeaker signals.

First claim

The invention claimed is:

1. A device for generating a multitude of loudspeaker signals based on at least one virtual source object which comprises a source signal and meta information determining a position or type of the at least one virtual source object, comprising:
a modifier configured to time-varyingly modify the meta information; and
a renderer configured to transfer the at least one virtual source object and the modified meta information in which the type or position of the at least one virtual source object is modified time-varyingly, to form a multitude of loudspeaker signals;
wherein the modifier is configured to at least one of:
modifying the meta information of the at least one virtual source object such that a virtual position of the at least one virtual source object is modified from one time instant to a later time instant and thereby a distance between the virtual position of the at least one virtual source object relative to a position in a playback space is altered by at most 25%;
modifying the meta information of the at least one virtual source object from one time instant to a later time instant such that, relative to a position in a playback space, an interaural level difference is increased by at most 26% or decreased by at most 21%;
modifying the meta information of the at least one virtual source object from one time instant to a later time instant such that, relative to a position in a playback space, a monaural level difference is increased by at most 26% or decreased by at most 21%; and
modify the meta information of the at least one virtual source object from one time instant to a later time instant such that, relative to a position in a playback space, an interaural time difference is modified by at most 30 .mu.s.

2. The device in accordance with claim 1 , further comprising:
a system calculator configured to estimate, based on a plurality of microphone signals and the multitude of loudspeaker signals, a transmission characteristic of a playback space where a plurality of loudspeakers which the multitude of loudspeaker signals is determined for and a plurality of microphones which the plurality of microphone signals originate from may be applied;
wherein the renderer is configured to calculate the multitude of loudspeaker signals based on the estimated transmission characteristic of the playback space.

3. The device in accordance with claim 1 , wherein the renderer is configured to calculate the multitude of loudspeaker signals in accordance with the rule of a wave-field synthesis algorithm or a high-order ambisonic algorithm, or wherein the renderer is configured to calculate at least 10 loudspeaker signals.

4. The device in accordance with claim 1 , wherein the modifier is configured to modify at least two virtual source objects such that the meta information of a first virtual source object are modified differently as regards position or type of the virtual source object compared to the meta information of a second virtual source object; and
wherein the renderer is configured to calculate the multitude of loudspeaker signals based on the first modified meta information and the second modified meta information.

5. The device in accordance with claim 1 , wherein the at least one virtual source object is arranged in the front relative to a listener in a playback space and the modifier is configured to modify the meta information of the at least one virtual source object from one time instant to a later time instant such that a direction of the at least one virtual source object relative to the listener is altered by less than 3°.

6. The device in accordance claim 1 , wherein the at least one virtual source object is arranged in a lateral direction relative to a listener in a playback space and the modifier is configured to modify the meta information of the at least one virtual source object from one time instant to a later time instant such that a direction of the at least one virtual source object relative to the listener is altered by less than 10%.

7. The device in accordance with claim 1 , wherein the modifier is configured to perform the meta information of the at least one virtual source object at a time interval of at least 10 seconds.

8. The device in accordance with claim 1 , wherein the modifier is additionally configured to produce an image of the at least one virtual source object, wherein the image at least partly comprises the meta information of the at least one virtual source object; and wherein the modifier is configured to time-varyingly modify the meta information such that the at least one virtual source object and the image comprise mutually different meta information.

9. The device in accordance with claim 8 , wherein the modifier is configured to position the image at a distance of at most 10 meters to the at least one virtual source object.

10. The device in accordance with claim 1 , wherein the modifier is configured to modify the meta information of the at least one virtual source object of a playback scene reproduced as regards the position or type of the at least one virtual source object partly such that the modification of the playback scene reproduced is not noticeable by a listener in a playback space or not perceived as being disturbing.

11. The device in accordance with claim 1 , wherein the renderer is additionally configured to add to the loudspeaker signals an attenuation or delay such that a correlation of the loudspeaker signals is reduced.

12. A method for generating a multitude of loudspeaker signals based on at least one virtual source object which comprises a source signal and meta information determining the position or type of the at least one virtual source object, comprising:
time-varyingly modifying the meta information; and
transferring the at least one virtual source object and the modified information in which the type or position of the at least one virtual source object is modified time-varyingly, to form a multitude of loudspeaker signals;
wherein time-varyingly modifying the meta information is performed so as to at least one of:
modifying the meta information of the at least one virtual source object such that a virtual position of the at least one virtual source object is modified from one time instant to a later time instant and thereby a distance between the virtual position of the at least one virtual source object relative to a position in a playback space is altered by at most 25%;
modifying the meta information of the at least one virtual source object from one time instant to a later time instant such that, relative to a position in a playback space, an interaural level difference is increased by at most 26% or decreased by at most 21%;
modifying the meta information of the at least one virtual source object from one time instant to a later time instant such that, relative to a position in a playback space, a monaural level difference is increased by at most 26% or decreased by at most 21%; and
modify the meta information of the at least one virtual source object from one time instant to a later time instant such that, relative to a position in a playback space, an interaural time difference is modified by at most 30 .mu.s.

13. A non-transitory digital storage medium having stored thereon a computer program for performing the method in accordance with claim 12 when said computer program is run by a computer.

Assignees

• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V

Inventors

• Schneider Martin
• Kellermann Walter
• Franck Andreas

Classifications

• H04S7/303

  Tracking of listener position or orientation · CPC title

• H04S2420/05

  Application of the precedence or Haas effect, i.e. the effect of first wavefront, in order to improve sound-source localisation · CPC title

• H04S5/00

  Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation · CPC title

• H04S7/301

  Automatic calibration of stereophonic sound system, e.g. with test microphone · CPC title

• H04S2420/13

  Application of wave-field synthesis in stereophonic audio systems · CPC title