DYNAMIC BINAURAL SOUND CAPTURE AND REPRODUCTION IN FOCUED OR FRONTAL APPLICATIONS

• US 20080056517A1
• Filed: 08/27/2007
• Published: 03/06/2008
• Est. Priority Date: 10/18/2002
• Status: Abandoned Application

• Current Assignee: California Polytechnic State University (California State University System)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Algazi, V., Duda, Richard, Thompson, Dennis
• Application Number:
  US11/845,607
• Publication Number:
  US 20080056517A1
• Time in Patent Office: Days
• US Class Current: 381/310
• CPC Class Codes: H04R 2201/401 2D or 3D arrays of transducers
• CPC Class Codes: H04R 2201/405 Non-uniform arrays of transducers or a plurality of uniform arrays with different transducer spacing
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 5/027 Spatial or constructional arrangements of microphones, e.g. in dummy heads
• CPC Class Codes: H04S 2400/01 Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
• CPC Class Codes: H04S 2400/15 Aspects of sound capture and related signal processing for recording or reproduction
• CPC Class Codes: H04S 7/304 For headphones

Abstract

A new approach to tracking head motion for headphone-based sound is described. Called MTB2.0 for “Motion-Tracked Binaural with 2 Channels”, the method may be used for any 2-channel binaural signals without any increase in the bandwidth requirement. MTB2.0 provides a simple and effective means to improve the quality of headphone-based sound reproduction by sensing the orientation of the listener'"'"'s head and using the sensed orientation to appropriately modify the signals sent to the two ears. MTB2.0 method increases the realism and removes some of the shortcomings of binaural sound capture and recording, as well as improves the quality of binaural rendering of stereo.

Claims

1. A sound reproduction apparatus for 2-channel binaural signals, comprising:

a signal processing unit;

said signal processing unit having an output for connection to an audio output device;

said signal processing unit having an input for connection to a head tracking device;

said signal processing unit configured to receive signals representative of the output of a plurality of microphones positioned to sample a sound field at points representing possible locations of a listener'"'"'s ear if said listeners'"'"' head were positioned in said sound field at the location of said microphones;

said signal processing unit configured to process said microphone output signals and present a binaural output to said audio output device in response to orientation of said listener'"'"'s head as indicated by said head tracking device;

wherein said plurality of microphones comprises two physical central microphones located at the positions of the ears of a listener facing forward;

wherein said plurality of microphones further comprises four simulated peripheral microphones located in pairs on either side of said central microphones;

wherein signals from said simulated microphones are not physically acquired but are estimated from the signals at the central microphones; and

whereby only the two binaural signals captured at the central microphones are required for sound reproduction.

2. A sound reproduction apparatus for 2-channel binaural signals, comprising:

a signal processing unit;

said signal processing unit having an output for connection to an audio output device;

said signal processing unit having an input for connection to a head tracking device;

said signal processing unit configured to receive signals representative of the output of a plurality of microphones positioned to sample a sound field at points representing possible locations of a listener'"'"'s left and right ears if said listeners'"'"' head were positioned in said sound field at the location of said microphones;

said signal processing unit configured to combine microphone output signals and present a binaural output to said audio output device in response to orientation of said listener'"'"'s head as indicated by said head tracking device;

wherein said plurality of microphones comprises two physical central microphones located at the positions of the ears of a listener facing forward;

wherein said plurality of microphones further comprises four simulated peripheral microphones located in pairs on either side of said central microphones;

wherein signals from said simulated microphones are not physically acquired but are estimated from the signals at the central microphones; and

whereby only the two binaural signals captured at the central microphones are required for sound reproduction.

3. A sound reproduction apparatus for 2-channel binaural signals, comprising:

a signal processing unit;

said signal processing unit having an output for connection to an audio output device;

said signal processing unit having an input for connection to a head tracking device;

said signal processing unit comprising means for receiving signals representative of the output of a plurality of microphones positioned to sample a sound field at points representing possible locations of a listener'"'"'s ear if said listeners'"'"' head were positioned in said sound field at the location of said microphones, and for processing said microphone output signals and presenting a binaural output to said audio output device in response to orientation of said listener'"'"'s head as indicated by said head tracking device;

wherein said plurality of microphones comprises two physical central microphones located at the positions of the ears of a listener facing forward;

wherein said plurality of microphones further comprises four simulated peripheral microphones located in pairs on either side of said central microphones;

wherein signals from said simulated microphones are not physically acquired but are estimated from the signals at the central microphones; and

whereby only the two binaural signals captured at the central microphones are required for sound reproduction.

4. An apparatus for dynamic binaural sound capture and reproduction for 2-channel binaural signals, comprising:

a plurality of microphones positioned to sample a sound field at points representing possible locations of an ear of a listener if said listener'"'"'s head were positioned in said sound field at the location of said microphones;

a signal processing unit;

said signal processing unit having an output for connection to an audio output device;

said signal processing unit having an input for connection to a head tracking device;

said signal processing unit configured to process said microphone output signals and present a binaural output to said audio output device in response to orientation of said listener'"'"'s head as indicated by said head tracking device;

wherein said plurality of microphones comprises two physical central microphones located at the positions of the ears of a listener facing forward;

wherein said plurality of microphones further comprises four simulated peripheral microphones located in pairs on either side of said central microphones;

wherein signals from said simulated microphones are not physically acquired but are estimated from the signals at the central microphones; and

whereby only the two binaural signals captured at the central microphones are required for sound reproduction.

5. An apparatus for dynamic binaural sound capture and reproduction for 2-channel binaural signals, comprising:

a plurality of microphones positioned to sample a sound field at points representing possible locations of a listener'"'"'s left and right ears if said listener'"'"'s head were positioned in said sound field at the location of said microphones; and

a signal processing unit;

said signal processing unit having an output for connection to an audio output device;

said signal processing unit having an input for connection to a head tracking device;

said signal processing unit configured to combine output signals from said microphones and present a binaural output to said audio output device in response to orientation of said listener'"'"'s head as indicated by said head tracking device;

wherein said plurality of microphones comprises two physical central microphones located at the positions of the ears of a listener facing forward;

wherein said plurality of microphones further comprises four simulated peripheral microphones located in pairs on either side of said central microphones;

wherein signals from said simulated microphones are not physically acquired but are estimated from the signals at the central microphones; and

whereby only the two binaural signals captured at the central microphones are required for sound reproduction.

6. An apparatus for dynamic binaural sound capture and reproduction for 2-channel binaural signals, comprising:

a plurality of microphones positioned to sample a sound field at points representing possible locations of an ear of a listener if said listener'"'"'s head were positioned in said sound field at the location of said microphones; and

a signal processing unit;

said signal processing unit having an output for connection to an audio output device;

said signal processing unit having an input for connection to a head tracking device;

said signal processing unit comprising means for processing said microphone output signals and presenting a binaural output to said audio output device in response to orientation of said listener'"'"'s head as indicated by said head tracking device;

wherein said plurality of microphones comprises two physical central microphones located at the positions of the ears of a listener facing forward;

wherein said plurality of microphones further comprises four simulated peripheral microphones located in pairs on either side of said central microphones;

wherein signals from said simulated microphones are not physically acquired but are estimated from the signals at the central microphones; and

whereby only the two binaural signals captured at the central microphones are required for sound reproduction.