Head tracking system

A system for generating a virtual surround sound signal, the system comprising:

• a light source positioned at a fixed point;
• a planar rectangular position sensitive device supported by a support structure, the light source configured to generate a light spot on the position sensitive device;
• a head position determining module configured to determine a head position based on a position of the light spot on the position sensitive device;
• a filter database comprising a plurality of filter elements, each filter element corresponding to a defined head position;
• and
• an audio signal processing module configured to receive an audio input signal, select at least one of the plurality of filter elements corresponding to the determined head position, filter the received audio input signal with the selected at least one filter element, and generate the virtual surround sound signal,
• where a surface normal of the position sensitive device in a head rest position points at the light source, and a diagonal between a pair of opposing corners of the position sensitive device in the head rest position is oriented substantially horizontally such that rotation of the position sensitive device in a substantially horizontal plane away from the head rest position results in a displacement of the light spot towards one of the pair of opposing corners of the position sensitive device.

A method for determining a head position of a user, the method comprising the steps of:

• emitting light with a light source toward a rectangular planar position sensitive device supported by a support structure, a diagonal between a pair of opposing corners of the position sensitive device being oriented substantially horizontally;
• generating a light spot on the position sensitive device with the emitted light;
• sensing a rotation of the position sensitive device in a substantially horizontal plane based on a displacement of the light spot towards one of the pair of opposing corners of the position sensitive device;
• and
• determining the head position based on a position of the light spot on the position sensitive device.

A method for generating a virtual surround sound signal, the method comprising the steps of:

• emitting light with a light source toward a rectangular planar position sensitive device supported by a support structure, a diagonal between a pair of opposing corners of the position sensitive device being oriented substantially horizontally;
• generating a light spot on the position sensitive device with the emitted light;
• sensing a rotation of the position sensitive device in a substantially horizontal plane based on a displacement of the light spot towards one of the pair of opposing corners of the position sensitive device;
• determining a head position based on a position of the light spot on the position sensitive device;
• determining a filter element corresponding to the determined head position;
• receiving an audio input signal;
• and
• filtering the audio input signal with the determined filter element to generate the virtual surround sound signal.