Switching binaural sound from head movements

1. A method executed by one or more electronic devices, the method comprising:

providing, with the one or more electronic devices and to a listener, binaural sound of a voice of a person that externally localizes to the listener at a sound localization point (SLP) that occurs in empty space in a field-of-view of the listener;

tracking, with the one or more electronic devices, head movements of the listener to detect when the SLP moves outside the field-of-view of the listener; and

reducing processing by the one or more electronic devices of the binaural sound to the SLP by switching, upon detecting that the head movements of the listener caused the SLP to move outside the field-of-view of the listener, the binaural sound to stereo sound while the listener continues to hear the voice of the person.

2. The method of claim 1 further comprising:

tracking, with the one or more electronic devices, the head movements of the listener to detect when the SLP moves back inside the field-of-view of the listener; and

switching the stereo sound back to the binaural sound upon detecting that the head movements of the listener caused the SLP to move back inside the field-of-view of the listener.

3. The method of claim 1 further comprising:

notifying the listener of the switching of the binaural sound to the stereo sound by displaying, with the one or more electronic devices, a visual warning to the listener when the SLP in the field-of-view of the listener moves to a perimeter of the field-of-view of the listener.

4. The method of claim 1 further comprising:

notifying the listener of a direction of the SLP when the SLP is outside the field-of-view of the listener by displaying, with the one or more electronic devices, a visual indication at a location on a perimeter of the field-of-view that shows the direction of the SLP.

5. The method of claim 1 further comprising:

reducing a volume of the voice of the person in response to detecting that the head movements of the listener caused the SLP to move outside the field-of-view of the listener.

6. The method of claim 1 further comprising:

switching the stereo sound back to the binaural sound;

detecting closure of eyes of the listener; and

switching, upon detecting the closure of the eyes of the listener, the binaural sound to the stereo sound while the listener continues to hear the voice of the person.

7. The method of claim 1 further comprising:

switching the stereo sound back to the binaural sound;

displaying, in the field-of-view of the listener, an area that represents the stereo sound;

detecting when a head of the listener is directed to the area that represents the stereo sound; and

switching, upon detecting the head of the listener is directed to the area that represents the stereo sound, the binaural sound to the stereo sound.

8. The method of claim 1 further comprising:

defining a perimeter with an area that includes a coordinate location of the SLP; and

determining when the head movements cause the coordinate location of the SLP to move outside the perimeter, wherein the switching the binaural sound to the stereo sound occurs when the coordinate location of the SLP moves outside the perimeter.

9. A non-transitory computer-readable storage medium that one or more electronic devices execute to reduce processing of sound that a listener hears, the method comprising:

playing, to the listener, the sound as binaural sound that externally localizes to the listener at a sound localization point (SLP) in empty space located in a field-of-view of the listener;

tracking head movements of the listener that determine when a head of the listener moves and causes the SLP to be outside the field-of-view of the listener; and

reducing processing of the sound by changing, upon determining that the head movements of the listener caused the SLP to be outside the field-of-view of the listener, the sound from playing in the binaural sound to playing in stereo sound while the listener continues to hear the sound.

10. The non-transitory computer-readable storage medium of claim 9 further comprising:

determining a perimeter on a display that includes the field-of-view of the listener; and

detecting when the SLP moves outside the perimeter, wherein the changing of the sound from playing as the binaural sound to playing as the stereo sound occurs when the SLP moves outside the perimeter.

11. The non-transitory computer-readable storage medium of claim 9 further comprising:

determining how much a coordinate location of the SLP moves with respect to a line-of-sight of the listener while the head of the listener moves; and

determining when movement of the coordinate location of the SLP with respect to the line-of-sight exceeds a threshold, wherein the changing of the sound from playing as the binaural sound to playing as the stereo sound occurs when the movement exceeds the threshold.

12. The non-transitory computer-readable storage medium of claim 9 further comprising:

changing the sound from playing in the stereo sound back to playing in the binaural sound;

detecting a voice of a person talking to the listener while the listener wears a head mounted display; and

changing, upon detecting the voice of the person talking to the listener, the sound from playing in the binaural sound to playing in the stereo sound while the listener continues to hear the sound.

13. The non-transitory computer-readable storage medium of claim 9 further comprising:

changing the sound from playing in the stereo sound back to playing in the binaural sound;

determining, based on the head movements, when a line-of-sight of the listener moves more than sixty degrees (60°) in an azimuth direction away from the SLP; and

changing the sound from playing in the binaural sound to playing in the stereo sound in response to determining that the line-of-sight of the listener moves more than sixty degrees (60°) in the azimuth direction away from the SLP.

14. The non-transitory computer-readable storage medium of claim 9 further comprising:

changing the sound from playing in the stereo sound back to playing in the binaural sound; and

changing the sound from playing in the binaural sound to playing in the stereo sound in response to determining that the head of the listener rotated one hundred and eighty degrees (180°) in an azimuth direction away from the SLP.

15. The non-transitory computer-readable storage medium of claim 9 further comprising:

displaying, to the listener and with a display, an area in the field-of-view that represents the stereo sound;

tracking the head movements of the listener to determine when a line-of-sight of the listener is directed to the area in the field-of-view that represents the stereo sound; and

changing, upon determining that the line-of-sight of the listener is directed to the area in the field-of-view that represents the stereo sound, the sound from playing in the binaural sound to playing in stereo sound.

16. A wearable electronic device comprising:

a memory that stores instructions;

head tracking that tracks head movements of the listener while the wearable electronic device plays sound to the listener; and

one or more processors that execute the instructions to:

process the sound into binaural sound that externally localizes to the listener at a sound localization point (SLP) in empty space located in a field-of-view of the listener, and

reduce processing of the sound by changing the sound from playing in the binaural sound to playing in stereo sound in response determining that the head movements of the listener caused the SLP to be outside the field-of-view of the listener.

17. The wearable electronic device of claim 16 further comprising:

a display that displays an image of a person at the SLP that remains at a fixed location to the listener while a head of the listener moves, and

wherein the one or more processors further execute the instructions to determine when the image of the person is no longer being displayed in the field-of-view of the listener and to change the sound from playing in the binaural sound to playing in the stereo sound.

18. The wearable electronic device of claim 16 further comprising:

a display that displays a light along a perimeter of the display to inform the listener of the SLP when the SLP is outside the field-of-view of the listener.

19. The wearable electronic device of claim 16 further comprising:

a display that displays an area in the field-of-view of the listener that represents the stereo sound, and

wherein the one or more processors further execute the instructions to detect when a head of the listener is directed to the area in the field-of-view of the listener that represents the stereo sound and to change the sound from playing in the binaural sound to playing in the stereo sound in response to detecting that the head of the listener is directed to the area.

20. The wearable electronic device of claim 16 , wherein the one or more processors further execute the instructions to:

display, while the sound plays to the listener in the binaural sound, the word “stereo” or the symbol “S” that when selected by the listener changes the sound from playing in the binaural sound to playing in the stereo sound, and display, while the sound plays to the listener in the stereo sound, the word “3D” that when selected by the listener changes the sound from playing in the stereo sound to playing in the binaural sound.