Acoustic signal output device
Provided is an open-ear acoustic signal output device worn on both ears, including a first signal output unit that outputs a first output signal for outputting a first monophonic acoustic signal from a first acoustic signal output unit worn on one ear, and a second signal output unit that outputs a second output signal for outputting a second monophonic acoustic signal from a second acoustic signal output unit worn on another ear. Here, in a case where the first monophonic acoustic signal is output from the first acoustic signal output unit and the second monophonic acoustic signal is output from the second acoustic signal output unit, an attenuation rate of the first monophonic acoustic signal at a second point with reference to a predetermined first point, where the first monophonic acoustic signal arrives at the first point and the second point is farther from the first acoustic signal output unit than the first point, is equal to or less than a predetermined value smaller than an attenuation rate due to air propagation of an acoustic signal at the second point with reference to the first point. Alternatively, an attenuation amount of the first monophonic acoustic signal at the second point with reference to the first point is equal to or more than a predetermined value larger than an attenuation amount due to air propagation of an acoustic signal at the second point with reference to the first point.
1 . An acoustic signal output device worn on both ears, comprising:
a first signal output unit that outputs a first output signal for outputting a first monophonic acoustic signal from a first acoustic signal output unit worn on one ear; and
a second signal output unit that outputs a second output signal for outputting a second monophonic acoustic signal from a second acoustic signal output unit worn on another ear,
wherein, in a case where the first monophonic acoustic signal is output from the first acoustic signal output unit and the second monophonic acoustic signal is output from the second acoustic signal output unit, an attenuation rate of the first monophonic acoustic signal at a second point with reference to a predetermined first point, where the first monophonic acoustic signal arrives at the first point and the second point is farther from the first acoustic signal output unit than the first point, is
equal to or less than a predetermined value smaller than an attenuation rate due to air propagation of an acoustic signal at the second point with reference to the first point, or
an attenuation amount of the first monophonic acoustic signal at the second point with reference to the first point is
equal to or more than a predetermined value larger than an attenuation amount due to air propagation of an acoustic signal at the second point with reference to the first point.
2 . The acoustic signal output device according to claim 1 ,
wherein the second monophonic acoustic signal is an antiphase signal of the first monophonic acoustic signal or an approximate signal of an antiphase signal of the first monophonic acoustic signal.
3 . The acoustic signal output device according to claim 1 , comprising:
the first acoustic signal output unit; and
the second acoustic signal output unit,
wherein the first acoustic signal output unit includes:
a first driver unit that emits a first acoustic signal to one side and emits a second acoustic signal that is an antiphase signal of the first acoustic signal or an approximate signal of an antiphase signal of the first acoustic signal to another side; and
a first housing in which a wall portion is provided with a single or a plurality of first sound holes for leading out the first acoustic signal emitted from the first driver unit to an outside and a single or a plurality of second sound holes for leading out the second acoustic signal emitted from the first driver unit to an outside,
the second acoustic signal output unit includes:
a second driver unit that emits a fourth acoustic signal that is same as or approximate to the second acoustic signal to one side and emits a third acoustic signal that is same as or approximate to the first acoustic signal to another side; and
a second housing in which a wall portion is provided with a single or a plurality of third sound holes for leading out the third acoustic signal emitted from the second driver unit to an outside and a single or a plurality of fourth sound holes for leading out the fourth acoustic signal emitted from the second driver unit to an outside,
the first acoustic signal is the first monophonic acoustic signal, and
the fourth acoustic signal is the second monophonic acoustic signal.
4 . The acoustic signal output device according to claim 3 ,
wherein the first sound holes of the first acoustic signal output unit worn on the one ear open in a first direction that is a direction toward the one ear,
the second sound holes open in a second direction between the first direction and a direction opposite to the first direction,
the fourth sound holes of the second acoustic signal output unit worn on the other ear open in a fourth direction that is a direction toward the other ear, and
the third sound holes open in a third direction between the fourth direction and a direction opposite to the fourth direction.
5 . The acoustic signal output device according to claim 4 ,
wherein a plurality of the second sound holes is provided along a first circumference centered on a first axis parallel or substantially parallel to a straight line extending in the first direction, and
a plurality of the third sound holes is provided along a fourth circumference centered on a fourth axis parallel or substantially parallel to a straight line extending in the fourth direction.
6 . The acoustic signal output device according to claim 5 ,
wherein, in a case where the first circumference is equally divided into a plurality of first unit arc regions, a sum of an opening area of the second sound holes provided along a first arc region that is one of the first unit arc regions is same as or substantially same as a sum of an opening area of the second sound holes provided along a second arc region that is one of the first unit arc regions excluding the first arc region, and
in a case where the fourth circumference is equally divided into a plurality of fourth unit arc regions, a sum of an opening area of the third sound holes provided along a third arc region that is one of the fourth unit arc regions is same as or substantially same as a sum of an opening area of the third sound holes provided along a fourth arc region that is one of the fourth unit arc regions excluding the third arc region.
7 . The acoustic signal output device according to claim 5 ,
wherein a position of the first sound holes is biased to a first eccentric position deviated from a first center axis extending in the first direction through a center region of the first housing,
in a case where the first circumference is equally divided into a plurality of first unit arc regions, a sum of an opening area of the second sound holes provided along a first arc region that is one of the first unit arc regions is smaller than a sum of an opening area of the second sound holes provided along a second arc region that is one of the first unit arc regions closer to the first eccentric position than the first arc region,
a position of the fourth sound holes is biased to a fourth eccentric position deviated from a second center axis extending in the fourth direction through a center region of the second housing, and
in a case where the second circumference is equally divided into a plurality of second unit arc regions, a sum of an opening area of the fourth sound holes provided along a third arc region that is one of the second unit arc regions is smaller than a sum of an opening area of the fourth sound holes provided along a fourth arc region that is one of the second unit arc regions closer to the fourth eccentric position than the third arc region.