An Open AL(Source) resource (previously created by openal_source_create()).
Property to get, one of: AL_SOURCE_RELATIVE (int), AL_SOURCE_STATE (int), AL_PITCH (float), AL_GAIN (float), AL_MIN_GAIN (float), AL_MAX_GAIN (float), AL_MAX_DISTANCE (float), AL_ROLLOFF_FACTOR (float), AL_CONE_OUTER_GAIN (float), AL_CONE_INNER_ANGLE (float), AL_CONE_OUTER_ANGLE (float), AL_REFERENCE_DISTANCE (float), AL_POSITION (array(float,float,float)), AL_VELOCITY (array(float,float,float)), AL_DIRECTION (array(float,float,float)).