Acoustic apparatus
When a listener 10 changes the reclining angle of a backrest part 101 a of a seat 101 and a head 10 a of the listener 10 is thereby caused to be present outside an audible area 120 a of a directional loudspeaker 120 or when the reclining angle of a front seat 100 is changed and the head 10 a of the listener 10 is thereby caused to be present outside the audible area 120 a of the directional loudspeaker 120 , a distance L 2 to an obstacle exceeds 1 m as an upper limit of a standard listening range and it is determined that the head 10 a of the listener 10 is present beyond the standard listening range, and the audio output of the directional loudspeaker 120 is stopped.
1. An acoustic apparatus for a listener sitting in a seat, comprising:
a directional loudspeaker arranged so as to face toward the listener;
a detection part for detecting whether or not the head of the listener is present within an audible area of the directional loudspeaker; and
a controller for controlling the magnitude of the audio output from the directional loudspeaker; wherein
the controller stops or reduces the audio output when the detection part has detected that the head of the listener is not present within the audible area of the directional loudspeaker;
the seat in which the listener sits includes a backrest and a reclining function for changing a reclining angle of the backrest;
a seat in front of and adjacent to the seat in which the listener sits includes a backrest with the directional loudspeaker installed in a back surface thereof, and the reclining function for changing a reclining angle of the backrest; and
the detection part detects whether or not the head of the listener is present within the audible area of the directional speaker, based on an angle difference between the reclining angle of the backrest of the seat in which the listener sits and the reclining angle of the backrest of the front adjacent seat.
2. The acoustic apparatus according to claim 1 , wherein the detection part detects the angle difference by using an angle sensor provided on the seat in which the listener sits and an angle sensor provided on the front adjacent seat.
3. The acoustic apparatus according to claim 1 , comprising a distance sensor for measuring a distance from the directional loudspeaker to an obstacle on the listener side; wherein:
the detection part detects whether or not the head of the listener is present within the audible area of the directional loudspeaker, based on the angle difference and the distance measured by the distance sensor.