System to move sound into and out of a listener's head using a virtual acoustic system

A method for rendering a sound program for headphones, at a sound location that is in a transition region, the method comprising:

• receiving a location for placing the sound program with respect to a listener wearing the headphones having a first ear piece that is closer to the location than a second ear piece;
• determining whether the location is between the first ear piece and a near-field boundary;
• in accordance with a determination that the location is between the first ear piece and a near-field boundary,
• filtering the sound program with first and second near-field binaural filters to produce a first near-field boundary signal and a second near-field boundary signal,
• filtering the sound program to produce a first in-head signal and a second in-head signal,
• calculating a blending factor that is proportional to a distance between the location and the first ear piece,
• panning the first and second near-field boundary signals and the first and second in-head signals based on the blending factor,
• combining i) the first near-field boundary signal attenuated by a first amount that is proportional to one minus the blending factor and ii) the first in-head signal attenuated by a second amount that is proportional to the blending factor, to produce a first headphone driver signal to drive the first ear piece, and
• combining i) the second near-field boundary signal attenuated by the first amount and ii) the second in-head signal attenuated by the second amount, to produce a second headphone driver signal to drive the second ear piece.

A device for rendering a sound program for headphones, the device comprising:

• a receiver that receives the sound program and a location for placing the sound program with respect to a first ear piece and a second ear piece of the headphones;
• a low-pass filter that produces a low-frequency portion of the sound program;
• a high-pass filter that produces a high-frequency portion of the sound program;
• a fader that pans the high-frequency portion according to the location, if a determination is made that the location is between the first ear piece and the second ear piece, to produce a first high-frequency panned signal and a second high-frequency panned signal;
• and
• a mixer that combines the low-frequency portion and the first high-frequency panned signal to produce a first headphone driver signal to drive the first ear piece, and combines the low-frequency portion and the second high-frequency panned signal to produce a second headphone driver signal to drive the second ear piece, if the determination is made that the location is between the first ear piece and the second ear piece.

A method for rendering a sound program for headphones using a virtual acoustic system, the method comprising:

• a) receiving a location at which a sound program is to be rendered;
• b) determining a rendering mode based on the received location being in-head, in a transition region, in a near-field region, or in a far-field region;
• and
• c) processing the sound program according to the determined rendering mode.