Area reproduction system and area reproduction method

1 . An area reproduction system, comprising:

a reproduction unit including a speaker array in which a plurality of speakers is arranged side by side;

an audio input unit that receives an input of a reproduced sound to be listened by a listener;

a sound collection unit that collects an environmental sound in a non-reproduction area different from a reproduction area in which a sound beam of the reproduced sound is emitted;

an acquisition unit that acquires a noise in the non-reproduction area included in the environmental sound and a leakage sound that is the reproduced sound leaking to the non-reproduction area;

a generation unit that generates a masking sound having a sound pressure higher than a sound pressure of the leakage sound on a basis of frequency characteristics of sound pressures of the noise and the leakage sound; and

a directivity control unit that adjusts directivity of the masking sound to be output from each of the plurality of speakers in such a manner that a sound beam of the masking sound is emitted to the non-reproduction area while avoiding the listener,

wherein the reproduction unit causes each of the plurality of speakers to output the masking sound with adjusted directivity, and

the directivity control unit adjusts the directivity of the masking sound in such a manner that a sound beam of the masking sound is mainly emitted from a speaker far from the listener.

2 . The area reproduction system according to claim 1 , wherein

the generation unit generates, as the masking sound, a sound obtained by adjusting a sound pressure of the noise or a sound acquired in advance to be higher than a sound pressure of the leakage sound at each of a plurality of frequencies.

3 . The area reproduction system according to claim 1 , wherein

in a case where the sound pressure of the noise is equal to or lower than a predetermined lower limit level, the generation unit stops generating the masking sound, and the reproduction unit stops outputting the masking sound.

4 . The area reproduction system according to claim 1 , wherein

in a case where the reproduced sound is a recorded sound,

the acquisition unit acquires the noise and a predicted leakage sound that is the reproduced sound predicted to leak to the non-reproduction area after a predetermined time, and

the generation unit generates a sound having a sound pressure higher than a sound pressure of the predicted leakage sound as the masking sound to be output after the predetermined time on a basis of frequency characteristics of sound pressures of the noise and the predicted leakage sound.

5 . The area reproduction system according to claim 1 , wherein

when it is detected that a sudden sound in which a sound pressure instantaneously increases is included in the noise, the generation unit removes the sudden sound from the noise, and then generates the masking sound on a basis of frequency characteristics of sound pressures of the noise from which the sudden sound has been removed and the leakage sound.

6 . The area reproduction system according to claim 1 , wherein

the directivity control unit adjusts a width and an emitting direction of the sound beam in such a manner that the sound beam of the masking sound avoids a head position of the listener.

7 . The area reproduction system according to claim 6 , further comprising:

a sensor that acquires information regarding a head position of the listener, wherein

the directivity control unit specifies the head position of the listener on a basis of the information regarding the head position of the listener acquired by the sensor.

8 . The area reproduction system according to claim 1 , wherein

the acquisition unit acquires, as the leakage sound, a sound obtained by convolving the reproduced sound received by the audio input unit with a predetermined transfer function of sound from an arrangement position of the reproduction unit to an arrangement position of the sound collection unit, and acquires, as the noise, a sound obtained by removing the acquired leakage sound from the environmental sound.

9 . An area reproduction method executed by a computer of an area reproduction system including a speaker array in which a plurality of speakers is arranged side by side, the area reproduction method comprising:

by the computer,

receiving an input of a reproduced sound to be listened by a listener;

collecting an environmental sound in a non-reproduction area different from a reproduction area in which a sound beam of the reproduced sound is emitted;

acquiring a noise in the non-reproduction area included in the environmental sound and a leakage sound that is the reproduced sound leaking to the non-reproduction area;

generating a masking sound having a sound pressure higher than a sound pressure of the leakage sound on a basis of frequency characteristics of sound pressures of the noise and the leakage sound;

adjusting directivity of the masking sound to be output from each of the plurality of speakers in such a manner that a sound beam of the masking sound is emitted to the non- reproduction area while avoiding the listener; and

causing each of the plurality of speakers to output the masking sound with adjusted directivity, wherein

in the adjustment, the directivity of the masking sound is adjusted in such a manner that a sound beam of the masking sound is mainly emitted from a speaker far from the listener.

10 . An area reproduction system, comprising:

a reproduction unit including a speaker array in which a plurality of speakers is arranged side by side;

an audio input unit that receives an input of a reproduced sound to be listened by a listener;

a sound collection unit that collects an environmental sound in a non-reproduction area different from a reproduction area in which a sound beam of the reproduced sound is emitted;

an acquisition unit that acquires a noise in the non-reproduction area included in the environmental sound and a leakage sound that is the reproduced sound leaking to the non-reproduction area;

a generation unit that generates a masking sound having a sound pressure higher than a sound pressure of the leakage sound on a basis of frequency characteristics of sound pressures of the noise and the leakage sound; and

a directivity control unit that adjusts directivity of the masking sound to be output from each of the plurality of speakers in such a manner that a sound beam of the masking sound is emitted to the non-reproduction area while avoiding the listener,

wherein the reproduction unit causes each of the plurality of speakers to output the masking sound with adjusted directivity, and

in a case where the sound pressure of the noise is equal to or lower than a predetermined lower limit level, the generation unit stops generating the masking sound, and the reproduction unit stops outputting the masking sound.

11 . The area reproduction system according to claim 10 , wherein

the directivity control unit adjusts the directivity of the masking sound in such a manner that a sound beam of the masking sound is emitted from a speaker farther from the listener as the speaker array is longer.

12 . An area reproduction method executed by a computer of an area reproduction system including a speaker array in which a plurality of speakers is arranged side by side, the area reproduction method comprising:

by the computer,

receiving an input of a reproduced sound to be listened by a listener;

collecting an environmental sound in a non-reproduction area different from a reproduction area in which a sound beam of the reproduced sound is emitted;

acquiring a noise in the non-reproduction area included in the environmental sound and a leakage sound that is the reproduced sound leaking to the non-reproduction area;

generating a masking sound having a sound pressure higher than a sound pressure of the leakage sound on a basis of frequency characteristics of sound pressures of the noise and the leakage sound;

adjusting directivity of the masking sound to be output from each of the plurality of speakers in such a manner that a sound beam of the masking sound is emitted to the non-reproduction area while avoiding the listener;

causing each of the plurality of speakers to output the masking sound with adjusted directivity; and

stopping the generation and the output of the masking sound in a case where the sound pressure of the noise is equal to or lower than a predetermined lower limit level.