Determining and using room-optimized transfer functions

Patent metadata

Field	Value
Publication number	US-10003906-B2
Application number	US-201615362017-A
Country	US
Kind code	B2
Filing date	Nov 28, 2016
Priority date	May 28, 2014
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

A device for determining room-optimized transfer functions for a listening room serving for room-optimized post-processing of audio signals in spatial production, is configured to analyze room acoustics of the listening room and to determine, based on the analysis of the room acoustics, the room-optimized transfer functions for the listening room where the spatial reproduction by means of a binaural close-range sound transducer is to take place. The spatial reproduction of the audio signals by means of the binaural close-range sound transducer may then be emulated using known head-related transfer functions und using the room-optimized transfer functions, wherein a room to be synthesized may be emulated based on the head-related transfer functions, and wherein the listening room may be emulated based on the room-optimized transfer functions.

First claim

The invention claimed is:

1. A device for determining room-optimized transfer functions for a listening room derived for the listening room and serving for room-optimized post-processing of audio signals in spatial reproduction, wherein the spatial reproduction of the audio signals is emulated by means of a binaural close-range sound transducer using known head-related transfer functions and using the room-optimized transfer functions,
wherein a room to be synthesized may be emulated based on the head-related transfer functions, and wherein the listening room may be emulated based on the room-optimized transfer functions,
wherein the device is configured to analyze room acoustics of the listening room and to determine, starting from analyzing the room acoustics, the room-optimized transfer functions for the listening room where the spatial reproduction by means of the binaural close-range sound transducer is to take place,
wherein the device comprises a storage in which may be deposited a plurality of room-optimized transfer function families for a plurality of listening rooms, wherein emulating the spatial reproduction is based on interaural features, balance features and distance features,
wherein the interaural features comprise a connection between a direction of incidence in the medial planes and an individual or non-individual head-related filtering, wherein the balance features comprise a connection between a lateral direction of incidence and a difference in volume and/or a connection between the lateral direction of incidence and a run-time difference, wherein the distance features comprise a connection between a virtual distance and frequency-dependent filtering and/or a connection between the virtual distance and an initial time gap and/or a connection between the virtual distance and a reflection behavior.

2. The device in accordance with claim 1 , wherein the room-optimized transfer functions comprise, per room, a plurality of transfer functions associated to individual solid angles.

3. The device in accordance with claim 1 , wherein the device comprises a microphone of a portable device for acoustic measurement and/or wherein analysis of the room acoustics of the listening room takes place by means of an acoustic measurement in the listening room using ambient noise and/or using a test signal.

4. The device in accordance with claim 3 , wherein the room-optimized transfer functions are selected such that room acoustics of the listening room may be emulated on the basis thereof.

5. The device in accordance with claim 1 , wherein the analysis of the room acoustics of the listening room is based on calculating a geometrical model of the listening room and/or modeling the geometrical model based on a camera-based model of the listening room.

6. The device in accordance with claim 1 , wherein the device is configured to determine the room-optimized transfer functions considering a virtual loudspeaker setup in correspondence with which a number of virtual loudspeakers are positioned in the listening room.

7. The device in accordance with claim 1 , wherein the known head-related transfer functions comprise a plurality of individual transfer functions for the left and right ears which are associated to directional vectors for a plurality of virtual sound sources.

8. The device in accordance with claim 1 , wherein the room-optimized transfer functions comprise a plurality of individual, directional transfer functions.

9. The device in accordance with claim 1 , wherein the binaural close-range sound transducer is a headset configured to output as the audio signal a multi-channel stereo signal, an object-based audio signal and/or an audio signal on the basis of a wave-field synthesis algorithm.

10. A method for determining room-optimized transfer functions for a listening room which are derived for the listening room and may serve for room-optimized post-processing of audio signals in spatial reproduction, wherein the spatial reproduction of the audio signals by means of a binaural close-range sound transducer is emulated using known head-related transfer functions and using the room-optimized transfer functions, wherein a room to be synthesized may be emulated based on the head-related transfer functions, and wherein the listening room may be emulated based on the room-optimized transfer functions,
comprising:
analyzing prevailing room acoustics of the listening room; and
determining the room-optimized transfer functions for the listening room where spatial reproduction by means of the binaural close-range sound transducer is to take place, on the basis of analyzing the room acoustics;
depositing a plurality of room-optimized transfer function families for a plurality of listening rooms, wherein emulating the spatial reproduction is based on interaural features, balance features and distance features,
wherein the interaural features comprise a connection between a direction of incidence in the medial planes and an individual or non-individual head-related filtering, wherein the balance features comprise a connection between a lateral direction of incidence and a difference in volume and/or a connection between the lateral direction of incidence and a run-time difference, wherein the distance features comprise a connection between a virtual distance and frequency-dependent filtering and/or a connection between the virtual distance and an initial time gap and/or a connection between the virtual distance and a reflection behavior.

11. The method in accordance with claim 10 , wherein the room-optimized transfer functions comprise, per room, a plurality of transfer functions associated to individual solid angles.

12. A device for spatial reproduction of an audio signal by means of a binaural close-range sound transducer, wherein the spatial reproduction is emulated using known head-related transfer functions and using room-optimized transfer functions for a listening room,
wherein a room to be synthesized may be emulated based on the head-related transfer functions, and wherein the listening room may be emulated based on the room-optimized transfer functions,
wherein the room-optimized transfer functions have been determined beforehand for the respective listening room;
wherein the device comprises a first storage in which are stored a first plurality of transfer function families for different listening rooms, and a position-determining unit,
wherein the position-determining unit is configured to identify the position and determine the listening room using the position identified; and
wherein the device is configured to select, for emulating the spatial reproduction, the corresponding transfer functions for the respective listening room from the transfer function families, wherein emulating the spatial reproduction is based on interaural features, balance features and distance features,
wherein the interaural features comprise a connection between a direction of incidence in the medial planes and an individual or non-individual head-related filtering, wherein the balance features comprise a connection between a lateral direction of incidence and a difference in volume and/or a connection between the lateral direction of incidence and a run-time difference, wherein the distance features comprise a connection between a virtual distance and frequency-dependent filtering and/or a connection between the virtual distance and an initial time gap and/or a connection between the virtual distance and a reflection behavior.

13. The device in accordance with claim 12 , wherein the room-optimized transfer functions comprise, per room, a plurality of transfer functions as

Assignees

• Fraunhofer Ges Forschung
• Univ Ilmenau Tech

Inventors

• Brandenburg Karlheinz
• Werner Stephan
• Sladeczek Christoph

Classifications

• H04S7/304

  For headphones · CPC title

• H04S7/301

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

• H04S2420/01

  Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD] · CPC title

• H04R3/00 Primary

  Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) · CPC title

• H04R2430/00

  Signal processing covered by H04R, not provided for in its groups · CPC title