An information processing apparatus comprising: circuitry (120, 123, 125, 126, 127, 128) configured to detect a current location of the information processing apparatus; obtain a direction of a destination from the detected current location as a target direction; detect a facial orientation of a user wearing a headphone unit comprising a geomagnetic sensor and an acceleration sensor connected to the information processing apparatus via a wired or wireless connection in relation to a reference orientation based on outputs of the geomagnetic sensor and the acceleration sensor; obtain a relative target angle based on a difference between the target direction and the user's facial orientation; and generate sound to be output by the headphone unit based on the obtained relative target angle; wherein in order to obtain said relative target angle the circuitry is configured to: obtain a horizontal plane based on a gravity vector obtained based on output of the acceleration sensor; obtain the reference orientation by projecting a geomagnetic vector obtained from an output of the geomagnetic sensor on the horizontal plane; and determine a direction of a straight line where a side face of the headphone unit which is in contact with the user's ear or a plane parallel to the side face intersects with the horizontal plane to be the facial orientation; and based on an angle θd as to the reference orientation of the target direction, and an angle θf as to the reference orientation of the facial orientation, obtain the relative target angle θx that the target direction makes up as to the user's facial orientation. circuitry (120, 123, 125, 126, 127, 128) configured to detect a current location of the information processing apparatus; obtain a direction of a destination from the detected current location as a target direction; detect a facial orientation of a user wearing a headphone unit comprising a geomagnetic sensor and an acceleration sensor connected to the information processing apparatus via a wired or wireless connection in relation to a reference orientation based on outputs of the geomagnetic sensor and the acceleration sensor; obtain a relative target angle based on a difference between the target direction and the user's facial orientation; and detect a current location of the information processing apparatus; obtain a direction of a destination from the detected current location as a target direction; detect a facial orientation of a user wearing a headphone unit comprising a geomagnetic sensor and an acceleration sensor connected to the information processing apparatus via a wired or wireless connection in relation to a reference orientation based on outputs of the geomagnetic sensor and the acceleration sensor; obtain a relative target angle based on a difference between the target direction and the user's facial orientation; and generate sound to be output by the headphone unit based on the obtained relative target angle; wherein in order to obtain said relative target angle the circuitry is configured to: obtain a horizontal plane based on a gravity vector obtained based on output of the acceleration sensor; obtain the reference orientation by projecting a geomagnetic vector obtained from an output of the geomagnetic sensor on the horizontal plane; and determine a direction of a straight line where a side face of the headphone unit which is in contact with the user's ear or a plane parallel to the side face intersects with the horizontal plane to be the facial orientation; and obtain a horizontal plane based on a gravity vector obtained based on output of the acceleration sensor; obtain the reference orientation by projecting a geomagnetic vector obtained from an output of the geomagnetic sensor on the horizontal plane; and determine a direction of a straight line where a side face of the headphone unit which is in contact with the user's ear or a plane parallel to the side face intersects with the horizontal plane to be the facial orientation; and based on an angle θd as to the reference orientation of the target direction, and an angle θf as to the reference orientation of the facial orientation, obtain the relative target angle θx that the target direction makes up as to the user's facial orientation.