Sound field control device and sound field control method

Abstract

To provide a sound field controller that can be installed easily in a room, creates a desired sound environment, and improves the degree of freedom of use purposes and use methods in the room.SOLUTION: A sound field controller comprises movement members 21, 22, a film member 30, an adjustment part 40, and an ultrasonic speaker 100. The movement member 21 is movable on a side wall surface 11 in a room; the movement member 22 is movable on a ceiling surface 12 in the room. The movement members 21, 22 are disposed so as to be freely movable close to / away from each other. The film member 30 is spread between the movement members 21, 22 and can reflect a sound wave 101. The adjustment part 40 changes at least either of the film member 30's shape and angle α with respect to an incident direction D11 of the sound wave 101 by changing respective positions of the movement members 21, 22. The ultrasonic speaker 100 can discharge the sound wave 101 to the film member 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sound field control device and a sound field control method. [Background technology]

[0002] Indoor sound field control in concert halls, exhibition halls, etc. can be broadly divided into two categories: direct sound control and indirect sound control. Direct sound control adjusts the output and direction of sound from sound sources such as speakers. Meanwhile, indirect sound control adjusts the direction of sound reflection and scattering by the interior walls of the room and reflectors and sound absorbers. In indoor sound field control, by using directional speakers such as highly directional ultrasonic speakers as wave sources, it is possible to narrow the radiation area of ​​sound waves, making it possible to efficiently radiate sound by targeting, for example, the listeners to whom the sound is to be delivered.

[0003] For example, Patent Document 1 discloses a local reproduction system including a sound emitting section, a sound reflecting section, a sound receiving means for directivity control, a sound receiving means for reflection direction control, a directivity control means, and a reflection direction control means. The sound receiving means for directivity control is fixed to the front side of the path of the radiated sound with respect to the directional speaker, receives the radiated sound radiated from the directional speaker in the sound emitting section, and receives a radiated sound receiving signal of the reflected sound from the reflection sound section. The sound receiving means for reflection direction control is fixed to the front side of the path of the reflected sound with respect to a reflecting plate disposed away from the directional speaker, receives the radiated sound radiated from the directional speaker in the sound section, and receives a reflected sound receiving signal of the reflected sound from the reflection sound section. The directivity control means controls the directivity of the directional speaker so that the radiated sound receiving signal is maximized. The reflection direction control means controls at least one of the shape of the reflecting plate and the direction of the reflecting surface so that the reflected sound receiving signal is maximized. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-008156 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional indoor sound field control technologies, including the above-mentioned local playback system, there was a problem that sound was emitted in unexpected directions due to the reflecting plates or reflecting surfaces of the reflecting devices, and the reflected sound from the side walls or ceiling of the room arrived at unintended places, resulting in a sound environment different from the setting. In order to create a sound environment as set, it is possible to fix the position of the listener in the room in advance, or to impose restrictions such as prohibiting people or devices from passing through the room, but in that case, there is another problem that the purpose and method of use of the room are significantly restricted.

[0006] The present invention provides a sound field control device that can be easily installed indoors, generates a desired sound environment, and increases the freedom of indoor use and usage, and a sound field control method using the sound field control device. [Means for solving the problem]

[0007] The sound field control device of the present invention comprises a plurality of movable members that are movable on an installation surface in a room and can be moved toward or away from each other, a membrane member stretched between the plurality of movable members and capable of reflecting sound waves, an adjustment unit that adjusts at least one of the angle and shape of the membrane member relative to the incident direction of the sound waves by changing the position of each of the plurality of movable members, and an ultrasonic speaker that can emit sound waves toward the membrane member.

[0008] The above-mentioned sound field control device has a simple and lightweight configuration consisting of at least a plurality of moving members, a membrane member, and an adjustment unit, and can be easily installed on any installation surface in a room. According to the above-mentioned sound field control device, the adjustment unit adjusts at least one of the angle and shape of the membrane member relative to the incident direction of the sound wave, so that the properties of the sound wave received by the membrane member can be adjusted to the desired properties by the angle and shape of the membrane member, reflected, and delivered to the listener. By adjusting the positions of the multiple moving members, the angle and shape of the membrane member can be adjusted in any pattern, and there is no restriction on activities in the room. Therefore, according to the above-mentioned sound field control device, a desired sound environment can be generated and the degree of freedom of use and method in the room can be increased.

[0009] In the above-mentioned sound field control device, the adjustment section may adjust the shape of the film member by changing the positions of each of the plurality of moving members and controlling the tension of the film member.

[0010] According to the above-mentioned sound field control device, the shape of the membrane member is adjusted by controlling the tension of the membrane member, and the sound waves incident on the membrane member are specularly reflected or diffused, thereby making it possible to control the strength of the reflected sound from the membrane member.

[0011] The above-mentioned sound field control device may be provided with a receiver arranged at a position away from the membrane member and receiving the sound waves reflected by the membrane member, and information regarding the sound waves received by the receiver may be fed back to the adjustment unit.

[0012] According to the above-mentioned sound field control device, the adjustment unit operates in response to information regarding the sound waves received by the receiver, and the properties of the sound waves received by the membrane member are adjusted to the desired properties by adjusting the angle and shape of the membrane member, so that the desired sound environment can be smoothly created.

[0013] The sound field control method of the present invention is a sound field control method for controlling the sound environment in a room using the above-mentioned sound field control device, and includes a calculation step of determining at least one of the angle and shape of the membrane member based on information regarding the reflection direction and intensity of sound waves reflected by the membrane member in accordance with information regarding the incident direction and intensity of sound waves incident on the membrane member, and an adjustment step of changing the position of each of the multiple movable members using the adjustment unit to match at least one of the angle and shape of the membrane member determined in the calculation step.

[0014] According to the above-mentioned sound field control method, in the calculation process, at least one of the angle and shape of the membrane member is calculated by back-calculation from information on the sound waves incident on the membrane member and information on the sound waves reflected from the membrane member. In the adjustment process, the positions of the multiple moving members are adjusted based on at least one of the information on the angle and shape of the membrane member calculated in the calculation process, and sound waves with desired properties are reflected from the membrane member. In other words, according to the above-mentioned sound field control method, the properties of the sound waves reflected from the membrane member can be controlled according to the information on the sound waves incident on the membrane member, and a desired sound environment can be created in the room. Effect of the Invention

[0015] According to the present invention, it is possible to provide a sound field control device that can be easily installed indoors, generates a desired sound environment, and increases the freedom of use and method of use within the room, and a sound field control method using the sound field control device. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of a room in which a sound field control device according to an embodiment of the present invention is installed. [Diagram 2] FIG. 2 is a side view of the sound field control device shown in FIG. [Diagram 3] FIG. 2 is a side view of the sound field control device shown in FIG. 1, illustrating the case where a sound wave is mirror-reflected. [Figure 4] FIG. 2 is a side view of the sound field control device shown in FIG. 1, illustrating the case where a sound wave spreads due to specular reflection. [Diagram 5] 2 is a schematic diagram of an ultrasonic speaker used in combination with the sound field control device shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sound field control device and a sound field control method according to an embodiment of the present invention will now be described with reference to the drawings.

[0018] As shown in FIG. 1 and FIG. 2, the sound field control device 20 of this embodiment is installed at a corner between a side wall surface (installation surface) 11 and a ceiling surface (installation surface) 12 of a hall 10 where, for example, a concert or a recital is held, and controls the sound field in the hall 10. As shown in FIG. 2, the sound field control device 20 includes moving members (a plurality of moving members) 21 and 22, a membrane member 30, an adjustment unit 40, an ultrasonic speaker 100, and a sound receiver 120. The moving member 21 is installed so as to be able to rise and fall (move) along the side wall surface 11 parallel to a vertical direction D1 that is parallel to the vertical direction. The moving member 21 slides and moves on a rail 27 (on the installation surface) formed on the opposing side wall surface 11 along the vertical direction D1. The moving member 22 is installed so as to be able to move along a ceiling surface 12 parallel to a horizontal direction D2. The moving member 22 slides and moves on a rail 28 (on the installation surface) formed on the opposing ceiling surface 12 along the horizontal direction D2, for example.

[0019] The membrane member 30 is stretched between the moving members 21 and 22. In other words, the moving members 21 and 22 are support members for the membrane member 30. When viewed from the room side of the hall 10, that is, from the seating side, the membrane member 30 is arranged so as to cover the corner between the side wall surface 11 and the ceiling surface 12. The membrane member 30 has elasticity and can be elastically deformed. The material of the membrane member 30 is, for example, a synthetic rubber plate, a resin base material made of acrylic or the like, a metal sheet made of aluminum (Al) or the like, a curtain cloth made of hemp (fiber) or the like, but is not particularly limited as long as at least one of the angle α and the shape with respect to the incident direction D11 of the sound wave 101 changes with the movement of each of the moving members 21 and 22, and the incident sound wave 101 can be reflected.

[0020] The adjustment unit 40 is physically or electrically connected to the moving members 21, 22, and is configured to be able to adjust at least one of the angle α and the shape of the membrane member 30 with respect to the incident direction D1 of the sound wave 101 by changing the positions of the moving members 21, 22. The adjustment unit 40 may adjust only the angle α of the membrane member 30, may adjust only the shape of the membrane member 30, or may adjust both the angle α and the shape of the membrane member 30, depending on how to control the properties of the sound wave 102 reflected by the membrane member 30.

[0021] Specifically, the adjustment unit 40 slides the moving members 21, 22 on the rails 27, 28 to change the positions of the moving members 21, 22 according to the desired angle and shape of the membrane member 30. The desired angle (membrane member angle) α that the membrane member 30 makes with respect to the incident direction D1 of the sound wave 101 and the shape of the membrane member 30 are appropriately determined according to the emission direction D2 and intensity setting value of the sound wave 102 reflected by the membrane member 30 and required according to the assumed sound environment created in the room. The adjustment unit 40 is, for example, a calculation device or processor such as a microcomputer, but is not particularly limited as long as it has a mechanism capable of executing the sliding movement of the moving members 21, 22 as described above.

[0022] As shown in Fig. 3, the ultrasonic speaker 100 is attached to a stand 110 suspended from the ceiling surface 12 shown in Fig. 1, and is disposed at the upper part of the hall 10 (room). The ultrasonic speaker 100 includes one or more radiators 104. The radiators 104 emit ultrasonic waves (sound waves) having high directivity as sound waves 101 along a radiation direction D10 (i.e., an incident direction D11 of the sound waves 101 to the membrane member 30). The stand 110 is configured to be drivable so that the radiation direction D10 can be directed in any direction depending on the installation position and direction of the sound field control device 20 in the hall 10.

[0023] The receiver 120 is provided at a position away from the membrane member 30 and at a position where it can receive at least the sound wave 102, and is arranged in the seating area of ​​the hall 10 as shown in FIG. 1, for example. The receiver 120 receives the sound wave 102 reflected by the membrane member 30. Information about the sound wave 102 received by the receiver 120 is fed back to the adjustment unit 40. The receiver 120 is physically or electrically connected to the adjustment unit 40 and is capable of data communication with the adjustment unit 40. The information about the sound wave 102 includes, for example, a data table showing the intensity of the sound wave 102 for each azimuth angle and each elevation angle. The adjustment unit 40 moves at least one of the moving members 21 and 22 according to the difference between the measurement value for the sound wave 102 acquired by the receiver 120 and the desired setting value for the sound wave 102, and adjusts at least one of the angle α and the shape of the membrane member 30. When the adjusting portion 40 is operated in this manner, the properties of the sound waves 102 reflected by the membrane member 30 are controlled as desired.

[0024] For example, as shown in FIG. 2 and FIG. 4, when a sound wave 101 emitted from an ultrasonic speaker 100 is incident on and hits the film member 30, it is reflected and emitted as a sound wave 102 in a reflection direction D12 different from the incident direction D11. If the moving members 21 and 22 are arranged so that the film member 30 forms a flat surface, the sound wave 101 is specularly reflected and reflected from the film member 30 as a sound wave 102. When the sound wave 101 is specularly reflected, as shown in FIG. 3, the angle θ' of the reflection direction D12 of the sound wave 102 reflected by the film member 30 with respect to the reflection surface 31 of the film member 30 is equal to the angle θ of the reflection surface 31 of the film member 30 with respect to the incident direction D11 of the sound wave 101. In other words, if the incident direction D11 of the sound wave 101 and the reflection direction D12 of the sound wave 102 are determined, the angle α of the film member 30 with respect to the incident direction D11 of the sound wave 101 is determined.

[0025] 2, when the moving members 21 and 22 are disposed at relative positions P1 and P2 and the membrane member 30 forms a flat surface, the sound wave 101 is incident on the reflecting surface 31 of the membrane member 30 which forms an angle α1 with respect to the incident direction D11, and the sound wave 102-1 reflected by the membrane member 30 reaches the target area A1 and the listener (not shown) in the target area A1. When the incident direction D11 of the sound wave 101 is fixed, when the moving members 21 and 22 move to relative positions P3 and P4 and the membrane member 30 forms a flat surface, the angle decreases from α1 to α2, and the sound wave 102-2 reflected by the membrane member 30 reaches the target area A2 and the listener in the target area A2. When the movable members 21 and 22 move further to the relative positions P5 and P6 and the membrane member 30 forms a flat surface, the angle decreases from α2 to α3, and the sound wave 102-3 reflected by the membrane member 30 reaches the target area A3 and the listener in the target area A3. As the angles α1, α2, and α3 become smaller in this order, the target areas A1, A2, and A3 approach the side wall surface 11 on which the movable member 21 is disposed in this order. In other words, the angle α of the membrane member 30 is determined when the incident direction D11 of the sound wave 101 and the position of the target area where the sound wave 102 arrives are determined.

[0026] As another form other than the form in which the membrane member 30 forms a flat surface, as shown in Fig. 5, the membrane member 30 is supported with a tension weaker than that in the state in which the membrane member 30 forms a flat surface, and forms a curved surface that is convex toward the center of the room. If the moving members 21 and 22 are arranged so that the membrane member 30 forms the above-mentioned curved surface, the sound wave 101 is specularly reflected and reflected from the membrane member 30 as a sound wave 102. At this time, the relationship of the above-mentioned angles θ and θ' is established for the sound wave 101 based on the tangent 33 of the reflecting surface 31 that passes through the position X where the sound wave 101 hits the membrane member 30. That is, the angles θ1' and θ2' that the reflection direction D12 of the sound wave 102 reflected by the membrane member 30 makes with the tangent 33 of the reflecting surface 31 of the membrane member 30 are equal to the angles θ1 and θ2 that the tangent 33 makes with the incident direction D11 of the sound wave 101. When the incident direction D11 of the sound wave 101 is fixed, the angle θ2 is smaller than the angle θ1, and therefore the angle θ2' is smaller than the angle θ1'. For this reason, when the sound wave 101 having a certain width with respect to the incident direction D1 is incident on the film member 30 forming a curved surface, the sound wave 102 has a larger width and spreads out as it moves away from the film member 30.

[0027] Next, a sound field control method of the present embodiment will be described. The sound field control method of the present embodiment is a method for controlling the sound environment in the hall 10 using the above-mentioned sound field control device 20, and includes a calculation step and an adjustment step.

[0028] In the calculation process, at least one of the angle α and the shape to be set for the membrane member 30 is obtained based on the information on the reflection direction D12 and the intensity of the sound wave 102 according to the information on the incident direction D11 and the intensity of the sound wave 101. Specifically, the information on the incident direction D11 and the intensity of the sound wave 101 and the above-mentioned information on the sound wave 101 are input in advance to the adjustment unit 40. The adjustment unit 40 receives information on the sound environment received at the position where the sound receiver 120 is installed, that is, information on the sound wave 102, from the sound receiver 120. The adjustment unit 40 obtains at least one of the angle α and the shape of the membrane member 30 to be set based on all the acquired information. The options for the shape of the membrane member 30 include all shapes that can be realized by the relative positions of the moving members 21 and 22 and the deformation characteristics including the elastic deformation of the membrane member 30, in addition to the flat surface and the curved surface exemplified above.

[0029] In the adjustment process, the adjustment unit 40 changes the positions of the movable members 21, 22 in accordance with at least one of the angle α and the shape of the membrane member 30 determined in the calculation process. That is, the adjustment unit 40 moves the movable members 21, 22 based on at least one of the information on the angle α and the shape of the membrane member 30 determined in the calculation process. The adjustment process adjusts the angle α and the shape of the membrane member 30, and the properties of the sound waves 102 are controlled as desired. Within the hall 10, an expected sound environment is created by the sound waves 102 controlled to the desired properties.

[0030] The sound field control device 20 of the present embodiment described above includes the moving members 21 and 22, the membrane member 30, the adjustment unit 40, and the ultrasonic speaker 100. The moving member 21 is movable on the side wall surface 11 in the hall 10. The moving member 22 is movable on the ceiling surface 12 in the hall 10. The moving members 21 and 22 are arranged so as to be able to move toward and away from each other. The membrane member 30 is stretched between the moving members 21 and 22, and is capable of reflecting the sound wave 101. The adjustment unit 40 adjusts at least one of the angle α and the shape of the membrane member 30 with respect to the incident direction D11 of the sound wave 101 by changing the positions of the moving members 21 and 22. The ultrasonic speaker 100 is capable of emitting the sound wave 101 toward the membrane member 30.

[0031] The sound field control device 20 of this embodiment has a simple and lightweight structure consisting of the moving members 21 and 22, the membrane member 30, and the adjustment unit 40, and can be easily installed on any installation surface in the hall 10. Therefore, the sound field control device 20 of this embodiment can be used as a temporary sound field control device or a sound field control device that is installed for a certain period of time. In addition, according to the sound field control device 20 of this embodiment, the adjustment unit 40 can move the moving members 21 and 22 to desired positions on the side wall surface 11 and the ceiling surface 12, respectively, and adjust the tension of the deformable membrane member 30, so that at least one of the angle α and the shape of the membrane member 30 with respect to the incident direction D11 of the sound wave 101 can be adjusted. As a result, the properties of the sound wave 101 incident on the membrane member 30 can be adjusted to the desired properties by the angle α and the shape of the membrane member 30, reflected, and delivered to the listener. According to the sound field control device 20 of this embodiment, by adjusting the positions of the movable members 21 and 22, the angle α and shape of the membrane member 30 can be freely adjusted in any pattern, without restricting the activities in the room. In other words, flexible local sound field control is possible according to the purpose of use of the hall 10 and the needs of the user. Therefore, it is possible to generate a desired sound environment in the hall 10 and increase the degree of freedom in the purpose and method of use of the hall 10.

[0032] In the sound field control device 20 of this embodiment, the adjustment section 40 can adjust the shape of the film member 30 by changing the positions of the movable members 21 and 22 and controlling the tension of the film member 30 .

[0033] According to the sound field control device 20 of this embodiment, the shape of the membrane member 30 can be easily adjusted by controlling the tension of the membrane member 30 using the adjustment unit 40. As a result, the sound waves 101 incident on the membrane member 30 are specularly reflected or diffused, so that the strength of the reflected sound from the membrane member 30 can be easily controlled.

[0034] The sound field control device 20 of this embodiment includes a receiver 120 that is provided at a position away from the membrane member 30 and receives the sound waves 102 reflected by the membrane member 30. In the sound field control device 20 of this embodiment, information related to the sound waves 102 received by the receiver 120 is fed back to the adjustment unit 40.

[0035] According to the sound field control device 20 of this embodiment, the adjustment unit 40 operates in response to information regarding the sound waves 102, and adjusts the properties of the sound waves 101 received by the membrane member 30 to the desired properties by adjusting the angle α and shape of the membrane member 30, so that the desired sound environment can be smoothly created within the hall 10.

[0036] The sound field control method of the present embodiment is a sound field control method for controlling the sound environment in the hall 10 using the above-mentioned sound field control device 20, and includes a calculation step and an adjustment step. In the calculation step, at least one of the angle α and shape of the membrane member 30 is calculated based on information on the reflection direction D12 and intensity of the sound wave 102 reflected by the membrane member 30 in accordance with information on the incident direction D11 and intensity of the sound wave 101 incident on the membrane member 30. In the adjustment step, the adjustment unit 40 changes the positions of the movable members 21, 22 in accordance with at least one of the angle α and shape of the membrane member 30 calculated in the calculation step.

[0037] In the calculation step of the sound field control method of this embodiment, at least one of the angle α and the shape of the membrane member for creating a desired sound environment in the hall 10 is calculated based on information on the sound waves 101, 102. In the adjustment step, the positions of the moving members 21, 22 are adjusted based on at least one of the information on the angle α and the shape of the membrane member calculated in the calculation step, and sound wave 102 with desired properties is reflected from membrane member 30. Therefore, according to the sound field control method of this embodiment, the properties of sound wave 102 can be controlled in accordance with information on sound wave 101, and a desired sound environment can be created in the hall 10.

[0038] Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and the present invention can be modified within the scope of the spirit of the present invention described in the claims.

[0039] For example, in the above embodiment, two moving members 21 and 22 are used as the multiple moving members, but the number of moving members is not limited to two and may be three or more. In addition, the connection points between the membrane member 30 and the multiple moving members are appropriately changed depending on the shape of the sound field control device and the mounting form on the installation surface.

[0040] In the above-described embodiment, a highly directional ultrasonic speaker 100 is used as a source of emitting sound waves 101, but the ultrasonic speaker 100 may be used constantly as a source of emitting sound waves 101 for creating a sound environment in the hall 10, or may be used temporarily during construction or initial setup of the sound field control device 20, or during maintenance or inspection.

[0041] In the above-described embodiment, the membrane member 30 specularly reflects the sound wave 101. In a sound field control device to which the present invention is applied, for example, at least a part of the reflecting surface 31 of the membrane member 30 may be formed with a scattering surface that scatters the sound wave 101 in all directions, or a fine structure with a unit length shorter than the wavelength of the sound wave 101. Due to such a scattering surface or fine structure, the sound wave 101 is diffused in multiple directions by the membrane member 30 compared to the case where the sound wave 101 is specularly reflected by a curved surface.

[0042] In the above embodiment, the sound field control device 20 is installed at the corner between the side wall surface 11 and the ceiling surface 12 of a hall 10 where, for example, a concert or a recital is held. However, the hall 10 is only one example of an installation environment for the sound field control device 20, and the sound field control device to which the present invention is applied can be installed on any installation surface in a room, for example, in a general office or entrance space. In addition, the sound field control device to which the present invention is applied is not limited to being installed at the corner between a side wall surface and a ceiling surface, but may be installed only on a side wall surface, only on a ceiling surface, on any installation surface other than a side wall surface or a ceiling surface, or even across a connection between any installation surfaces. [Explanation of symbols]

[0043] 20...Sound field control device 21, 22...moving member (plural moving members) 30...Membrane member 40…Adjustment section 50...Sound receiver 100...Ultrasonic speaker

Claims

1. A plurality of movable members arranged on an installation surface in a room so as to be movable toward and away from each other; A film member stretched between the plurality of moving members and capable of reflecting sound waves; an adjustment unit that adjusts at least one of an angle and a shape of the membrane member with respect to the incident direction of the sound wave by changing the position of each of the plurality of moving members; an ultrasonic speaker capable of emitting sound waves toward the membrane member; A sound field control device comprising:

2. the adjustment unit adjusts the shape of the membrane member by changing the positions of each of the plurality of moving members and controlling the tension of the membrane member. The sound field control device according to claim 1 .

3. a sound receiver provided in the room at a position separated from the membrane member and configured to receive the sound waves reflected by the membrane member; Information about the sound waves received by the receiver is fed back to the adjustment unit. The sound field control device according to claim 1 or 2.

4. A sound field control method for controlling a sound environment in a room using the sound field control device according to any one of claims 1 to 3, comprising: a calculation step of determining at least one of an angle and a shape of the membrane member based on information about a direction of reflection and an intensity of a sound wave reflected by the membrane member in response to information about a direction of incidence and an intensity of the sound wave incident on the membrane member; an adjustment step of changing the position of each of the plurality of movable members by the adjustment unit in accordance with at least one of the angle and the shape of the membrane member calculated in the calculation step; A sound field control method comprising:

Images