Spatial repositioning of multiple audio streams
An audio rendering system includes a processor that combines audio input signals with personalized spatial audio transfer functions preferably including room responses. The personalized spatial audio transfer functions are selected from a database having a plurality of candidate transfer function datasets derived from in-ear microphone measurements for a plurality of individuals. Alternatively, the personalized transfer function datasets are derived from actual in-ear measurements of the listener. Foreground and background positions are designated and matched with transfer function pairs from the selected dataset for the foreground and background direction and distance. Two channels of input audio such as voice and music are processed. When a voice communication such as a phone call is accepted the music being rendered is moved from a foreground to a background channel corresponding to a background spatial audio position using the personalized transfer functions. The voice call is simultaneously transferred to the foreground channel.
1. A method for distinguishing between a first audio channel and a second audio channel comprising:
associating the first audio channel with a first spatial audio position;
transitioning between the first spatial audio position and a second spatial audio position by associating the first audio channel with a first transition path by rendering the first audio channel with a third spatial audio transfer function that includes an HRF or a Binaural Room Transfer Function (BRTF) corresponding to a third spatial audio position along the first transition path;
associating the first audio channel with the second spatial audio position by rendering the first audio channel with a second spatial audio transfer function that includes an HRF or a BRTF corresponding to the second spatial audio position; and
associating the second audio channel with the first spatial audio position after the first audio channel vacates its association with the first spatial audio position,
wherein associating the first audio channel with the first spatial audio position includes rendering the first audio channel with a first spatial audio transfer function that includes an HRF or a BRTF corresponding to the first spatial audio position, and
wherein associating the second audio channel with the first spatial audio position includes rendering the second audio channel with the first spatial audio transfer function.
2. The method as recited in claim 1 , wherein the first spatial audio transfer function, the second spatial audio transfer function, and the third spatial audio transfer function are derived by accessing a database that includes non individualized Head Related Transfer Functions (HRTFs) or BRTFs.
3. The method as recited in claim 1 , wherein the first spatial audio transfer function and the second spatial audio transfer function are derived by accessing a database that includes individualized HRTFs or BRTFs.
4. The method as recited in claim 1 , wherein the first spatial audio position represents a foreground position and the second spatial audio position represents a background position.
5. The method as recited in claim 1 , wherein first spatial audio position represents a foreground position and the second spatial audio position represents a background position.
6. The method as recited in claim 1 , wherein transitioning between the first spatial audio position and the second spatial audio position occurs by using at least one interim or intermediate position in the transition path by using an HRTF or BRTF customized for an individual.
7. The method as recited in claim 1 , wherein the transitioning occurs in an abrupt manner.
8. The method as recited in claim 1 , wherein the first audio channel and the second audio channel correspond to tracks in a video game.
9. The method as recited in claim 1 , wherein the first audio channel corresponds to a media track and the second audio channel corresponds to a phone call.
10. The method as recited in claim 1 , wherein the receipt of a phone call triggers the transitioning of the first audio channel from the first spatial audio position to the second spatial audio position.
11. The method as recited in claim 1 , further comprising receiving a control signal that results in the transition of the first audio channel from the second spatial audio position to the first spatial audio position.
12. An audio processing device comprising:
a processor configured to render at least a first and a second audio stream at a plurality of spatial audio positions to include at least a first and second spatial audio position;
a memory having a plurality of spatial audio transfer functions for rendering audio for at least a first and a second spatial audio position; and
a selection processor configured to access a database including a plurality of candidate spatial audio transfer function pairs, said pairs accessed and indexed by image based physical properties for a listener and selected ones of said pairs used for positioning the first and second audio streams.
13. The audio processing device as recited in claim 12 wherein the database is located remotely from the audio processing device.
14. The audio processing device as recited in claim 12 wherein upon receipt of a control signal the processor is configured to move the first audio stream from a foreground position corresponding to the first spatial audio position to a background position corresponding to the second spatial audio position and to render the second audio stream into the vacated first spatial audio position.
15. The audio processing device as recited in claim 14 wherein the audio processing device is a mobile phone and the control signal is generated by the receipt of a telephone call.
16. The audio processing device as recited in claim 15 wherein the processor is further configured to attenuate the first audio stream upon receipt of the phone call.
17. A method for processing audio streams comprising:
receiving at least two audio streams;
assigning each of the at least two audio streams to different ones of spatial audio transfer functions, wherein each of the spatial audio transfer function are personalized for a user and wherein the personalized spatial audio transfer functions are selected from a database having a plurality of candidate transfer function datasets derived from in-ear microphone measurements for a plurality of individuals and indexed according to image based properties; and
selecting one of the audio streams to be a foreground stream and one to be a background stream based on the assignment to spatial audio transfer functions.
18. The method as recited in claim 17 wherein the spatial audio transfer functions comprise HRTFs or BRTFs and the at least two audio streams are rendered over headphones.