Noise suppression device, noise suppression method, and program

Abstract

Provided is noise suppression technology that, when a specific event that a user needs to recognize is occurring even during execution of a process for suppressing noise around the user, makes it possible to cause the user to recognize that such an event is occurring. The present invention provides a noise suppression device that, when noise from the surroundings of the user includes a sound (hereinafter referred to as event sound) originating from a predetermined event, causes the user to recognize that the event is occurring.

Description

[Technical Field]

[0001] The present invention relates to active noise control technology. [Background technology]

[0002] Active noise control technology is a technology that suppresses noise at specific locations, such as around a user. For example, by incorporating it into a vehicle, it suppresses sounds from outside the vehicle, allowing the user to hear desired sounds, such as phone calls or music, inside the vehicle. Active noise control technology typically uses a system that includes a reference microphone that picks up noise, an error microphone that picks up sounds at the user's location, a noise suppression device that generates a cancellation sound signal to cancel the noise from a noise signal output by the reference microphone and an error signal output by the error microphone, and a speaker that emits a sound based on the cancellation sound signal (hereinafter referred to as the cancellation sound) (see Non-Patent Document 1). This system repeatedly determines what kind of cancellation sound should be emitted from the speaker to suppress the noise, while measuring the degree to which the noise picked up by the reference microphone is suppressed using an error microphone installed near the user. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Yoshinobu Kajikawa, "Recent Topics and Applications of Active Noise Control," Information Processing Society of Japan Technical Report, Vol.2015-MUS-107, No.3, pp.1-6, 2015. Summary of the Invention [Problem to be solved by the invention]

[0004] However, completely blocking external sounds can cause inconvenience to the user. For example, blocking the siren of an emergency vehicle while driving can result in the user not being able to notice the approach of the emergency vehicle, or not noticing it too late. Therefore, rather than blocking all external sounds, it is preferable to allow the user to be aware of sounds necessary for recognizing the external situation.

[0005] Therefore, the present invention aims to provide a noise suppression technology that can make a user aware of the occurrence of a specific event that the user needs to be aware of, even when a process to suppress noise around the user is being executed. [Means for solving the problem]

[0006] In one aspect of the present invention, when a sound resulting from a predetermined event (hereinafter referred to as an event sound) is included in noises around a user, the user is made aware that the event is occurring. [Effects of the Invention]

[0007] According to the present invention, even when a process for suppressing noise around the user is being executed, if a specific event that the user needs to be aware of is occurring, the user can be made aware of the occurrence of the event. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing the configuration of a noise suppression device 100. FIG. [Figure 2] 3 is a flowchart showing the operation of the noise suppression device 100. [Figure 3] FIG. 2 is a block diagram showing the configuration of a noise suppression device 200. [Figure 4] 4 is a flowchart showing the operation of the noise suppression device 200. [Figure 5]FIG. 2 is a diagram illustrating an example of the functional configuration of a computer that realizes each device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. Components having the same functions are given the same numbers, and duplicated explanations will be omitted.

[0010] First Embodiment When a sound resulting from a predetermined event (hereinafter referred to as an event sound) is included in the noise around the user, the noise suppression device 100 makes the user aware that an event is occurring.

[0011] The noise suppression device 100 will be described below with reference to Figs. 1 and 2. Fig. 1 is a block diagram showing the configuration of the noise suppression device 100. Fig. 2 is a flowchart showing the operation of the noise suppression device 100. As shown in Fig. 1, the noise suppression device 100 includes a situation identification result generation unit 110, a notification signal generation unit 120, a cancellation sound signal generation unit 130, and a recording unit 190. The recording unit 190 is a component that appropriately records information necessary for the processing of the noise suppression device 100.

[0012] The noise suppression device 100 is connected to one or more sensors (not shown) to acquire data (hereinafter referred to as sensor data) used to identify the situation around the user. For example, a microphone, a camera, or a vibration detection sensor can be used as the sensor. In other words, the situation around the user is identified using sounds, images, and vibrations around the user. The noise suppression device 100 is also connected to a situation presentation device (not shown) to make the user aware that an event is occurring. For example, a speaker, a display, or a mobile terminal such as a mobile phone or a smartphone can be used as the situation presentation device. In other words, the user is made aware that an event is occurring using sounds, images, and vibrations.

[0013] The noise suppression device 100 is connected to one or more microphones (not shown, hereinafter referred to as reference microphones) for acquiring noise around the user and one or more microphones (not shown, hereinafter referred to as error microphones) for acquiring sounds heard by the user. The noise suppression device 100 is also connected to one or more speakers (not shown) for emitting sounds based on the cancellation sound signal, i.e., cancellation sounds.

[0014] The operation of the noise suppression device 100 will be described with reference to FIG.

[0015] In S110, the situation identification result generation unit 110 receives sensor data acquired using a sensor as input, and generates and outputs a situation identification result using the sensor data, which indicates whether an event is occurring around the user. For example, if the sensor data is the sound of a railroad crossing, the situation identification result generation unit 110 uses existing voice recognition technology to generate a situation identification result indicating to the user that a train is approaching the railroad crossing. Also, for example, if the sensor data is a video or image of a railroad crossing closing, the situation identification result generation unit 110 uses existing image recognition technology to generate a situation identification result indicating to the user that a train is approaching the railroad crossing. Also, for example, if a vibration detection sensor detects a sudden vibration, the situation identification result generation unit 110 generates a situation identification result indicating to the user that the user may have collided with an obstacle.

[0016] For example, the situation identification result generating unit 110 calculates a value indicating the degree of correlation between a reference sound for determining whether a sound originates from a predetermined event and the noise around the user, and if the value is greater than or equal to a predetermined threshold, generates a situation identification result indicating that an event is occurring around the user, and otherwise generates a situation identification result indicating that no event is occurring around the user. Note that the reference sound may be recorded in advance in the recording unit 190.

[0017] In S120, the notification signal generation unit 120 receives the situation identification result generated in S110 as input, and if the situation identification result indicates that an event is occurring around the user, generates and outputs a notification signal that notifies the user that an event is occurring. The situation presentation device receives the notification signal generated in S120 as input, and presents notification content to the user based on the notification signal. If the situation presentation device is a speaker, the notification signal is a notification sound signal that notifies the user that an event is occurring. If the situation presentation device is a display, the notification signal is a notification video signal that notifies the user that an event is occurring. If the situation presentation device is a mobile terminal, the notification signal is a notification vibration signal that notifies the user that an event is occurring.

[0018] In S130, the cancellation sound signal generation unit 130 receives as input a noise signal around the user acquired using one or more reference microphones and a received sound signal of the user acquired using one or more error microphones, generates a cancellation sound signal that cancels the noise from the noise signal and the received sound signal, and outputs the generated cancellation sound signal. The speaker receives as input the cancellation sound signal generated in S130, and emits a sound based on the cancellation sound signal.

[0019] The cancellation sound signal generation unit 130 can also generate a cancellation sound signal without using a noise signal. In this case, in S130, the cancellation sound signal generation unit 130 receives a received sound signal of the user acquired using one or more error microphones, generates a cancellation sound signal from the received sound signal, and outputs the cancellation sound signal that cancels the noise.

[0020] According to an embodiment of the present invention, even when a process for suppressing noise around the user is being executed, if a specific event that the user needs to be aware of is occurring, the user can be made aware of the occurrence of the event.

[0021] Second Embodiment When a sound resulting from a predetermined event (hereinafter referred to as an event sound) is included in the noise around the user, the noise suppression device 200 makes the user aware that an event is occurring.

[0022] The noise suppression device 200 will be described below with reference to Figs. 3 and 4. Fig. 3 is a block diagram showing the configuration of the noise suppression device 200. Fig. 4 is a flowchart showing the operation of the noise suppression device 200. As shown in Fig. 3, the noise suppression device 200 includes a situation identification result generation unit 210, an adjustment information generation unit 220, a cancellation sound signal generation unit 230, and a recording unit 290. The recording unit 290 is a component that appropriately records information necessary for the processing of the noise suppression device 200.

[0023] Like the noise suppression device 100, the noise suppression device 200 is connected to one or more sensors (not shown) to acquire data (hereinafter referred to as sensor data) used to identify the situation around the user.

[0024] Similar to the noise suppression device 100, the noise suppression device 200 is connected to one or more microphones (not shown, hereinafter referred to as reference microphones) for acquiring noise around the user and one or more microphones (not shown, hereinafter referred to as error microphones) for acquiring sounds heard by the user. Also, similar to the noise suppression device 100, the noise suppression device 200 is connected to one or more speakers (not shown) for emitting sounds based on the cancellation sound signal, i.e., cancellation sounds.

[0025] The operation of the noise suppression device 200 will be described with reference to FIG.

[0026] In S210, the situation identification result generation unit 210 receives sensor data acquired using a sensor as input, generates a situation identification result indicating the likelihood that an event is occurring around the user using the sensor data, and outputs the result. The value of the situation identification result may be a binary value, either a value indicating that an event is occurring around the user or a value indicating that an event is not occurring around the user, or a value indicating the degree of correlation between a reference sound for determining whether a sound originates from a predetermined event and the noise around the user. Note that the reference sound may be recorded in advance in the recording unit 290. When the value of the situation identification result is a binary value, the situation identification result generation unit 210 calculates, for example, a value indicating the degree of correlation between a reference sound for determining whether a sound originates from a predetermined event and the noise around the user. If the value is greater than or equal to a predetermined threshold, the situation identification result generation unit 210 generates a situation identification result indicating that an event is occurring around the user. Otherwise, the situation identification result generation unit 210 generates a situation identification result indicating that no event is occurring around the user. Furthermore, when the value of the situation identification result is a value indicating the degree of correlation, the situation identification result generation unit 210 calculates, for example, a value indicating the degree of correlation between a reference sound for determining whether a sound originates from a specified event and the noise around the user, and sets the value indicating the degree of correlation as the situation identification result.

[0027] In S220, the adjustment information generation unit 220 receives the situation identification result generated in S210 as input, and generates and outputs information (hereinafter referred to as adjustment information) regarding the relative volume of the event sound cancellation sound that cancels the event sound relative to the cancellation sound that cancels noise determined in accordance with the value of the situation identification result. When the value of the situation identification result is a binary value, either a value indicating that an event is occurring around the user or a value indicating that an event is not occurring, if the value of the situation identification result is a value indicating that an event is occurring around the user, the adjustment information generation unit 220 generates, as adjustment information, information indicating that the event sound cancellation sound is to be excluded from the cancellation sound. Furthermore, when the value of the situation identification result is a value indicating the degree of correlation between a reference sound for determining a sound originating from a predetermined event and noise around the user, the adjustment information generation unit 220 generates, as adjustment information, information indicating that the proportion of event sound cancellation sound to be excluded from the cancellation sound increases as the value of the situation identification result increases.

[0028] For example, if the sensor data is video or images for determining whether a railroad crossing is closed, the situation identification result generation unit 210 uses existing image recognition technology to generate a binary situation identification result, one value indicating to the user that a train is approaching the railroad crossing and one value indicating to the user that a train is not approaching the railroad crossing. If the situation identification result is a value indicating to the user that a train is approaching the railroad crossing, the adjustment information generation unit 220 generates, as adjustment information, a sound that eliminates sounds in a specific frequency band corresponding to the railroad crossing sound, as the event sound eliminating sound, and information indicating that the event sound eliminating sound is to be excluded from the eliminating sounds.

[0029] In S230, the cancellation sound signal generation unit 230 receives as input a noise signal around the user acquired using one or more reference microphones, a received sound signal of the user acquired using one or more error microphones, and the adjustment information generated in S220, and generates and outputs a cancellation sound signal that cancels the noise from the noise signal, the received sound signal, and the adjustment information. The speaker receives as input the cancellation sound signal generated in S230, and emits a sound based on the cancellation sound signal.

[0030] The cancellation sound signal generation unit 230 can also generate a cancellation sound signal without using a noise signal. In this case, in S230, the cancellation sound signal generation unit 230 receives the user's received sound signal acquired using one or more error microphones and the adjustment information generated in S220 as input, generates a cancellation sound signal that cancels noise from the received sound signal and the adjustment information, and outputs the generated cancellation sound signal.

[0031] According to an embodiment of the present invention, even when a process for suppressing noise around the user is being executed, if a specific event that the user needs to be aware of is occurring, the user can be made aware of the occurrence of the event.

[0032] <Additional Notes> 5 is a diagram showing an example of the functional configuration of computer 2000 that realizes each of the above-mentioned devices. The processing in each of the above-mentioned devices can be performed by having recording unit 2020 load a program that causes computer 2000 to function as each of the above-mentioned devices, and having control unit 2010, input unit 2030, output unit 2040, etc. operate.

[0033] The device of the present invention may, for example, be a single hardware entity having an input unit to which a keyboard or the like can be connected, an output unit to which an LCD display or the like can be connected, a communication unit to which a communication device (e.g., a communication cable) capable of communicating with an external device can be connected, a CPU (which may also include a central processing unit, cache memory, registers, etc.), memories such as RAM and ROM, an external storage device such as a hard disk, and buses connecting these input unit, output unit, communication unit, CPU, RAM, ROM, and external storage device so that data can be exchanged between them. If necessary, the hardware entity may also be provided with a device (drive) capable of reading and writing to a recording medium such as a CD-ROM. A physical entity equipped with such hardware resources includes a general-purpose computer.

[0034] The external storage device of the hardware entity stores the programs required to realize the above-mentioned functions and the data required for processing these programs (the programs may be stored in a ROM, which is a read-only storage device, for example, instead of an external storage device). Data obtained by processing these programs is stored in RAM, the external storage device, etc. as appropriate.

[0035] In a hardware entity, each program stored in an external storage device (or ROM, etc.) and the data required to process each program are loaded into memory as needed, and interpreted, executed, and processed by the CPU as appropriate, resulting in the CPU realizing a predetermined function (each component represented as the above, "unit," "means," etc.).

[0036] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Furthermore, the processes described in the above embodiments may not only be executed in chronological order according to the order described, but may also be executed in parallel or individually depending on the processing capacity of the device that executes the processes or as needed.

[0037] As described above, when the processing functions of the hardware entities (apparatuses of the present invention) described in the above embodiments are realized by a computer, the processing contents of the functions that the hardware entities should have are described by a program. Then, by executing this program on a computer, the processing functions of the hardware entities are realized on the computer.

[0038] The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory. Specifically, examples of the magnetic recording device include a hard disk drive, a flexible disk, and a magnetic tape. Examples of the optical disk include a DVD (Digital Versatile Disc), a DVD-RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only Memory), and a CD-R (Recordable) / RW (Rewritable). Examples of the magneto-optical recording medium include an MO (Magneto-Optical disc), and examples of the semiconductor memory include an EEP-ROM (Electronically Erasable and Programmable-Read Only Memory).

[0039] The program may be distributed, for example, by selling, transferring, lending, etc. a portable recording medium such as a DVD or CD-ROM on which the program is recorded. Furthermore, the program may be stored in a storage device of a server computer, and then transferred from the server computer to another computer via a network, thereby distributing the program.

[0040] A computer that executes such a program may first temporarily store the program recorded on a portable recording medium or transferred from a server computer in its own storage device. Then, when executing a process, the computer reads the program stored in its storage device and executes the process in accordance with the read program. Alternatively, the computer may read the program directly from a portable recording medium and execute the process in accordance with the program. Furthermore, the computer may execute the process in accordance with each program transferred from the server computer. Alternatively, the server computer may not transfer the program to the computer, but may execute the process through a so-called ASP (Application Service Provider) service, which realizes the processing function by issuing an execution instruction and obtaining the results. In this embodiment, the program includes information used for processing by a computer that is equivalent to a program (such as data that is not a direct instruction to the computer but has properties that define computer processing).

[0041] In addition, in this embodiment, a hardware entity is configured by executing a predetermined program on a computer, but at least a part of the processing contents may be realized by hardware.

[0042] The foregoing description of the embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and to enable those skilled in the art to utilize the invention in various embodiments and with various modifications as may be suitable for the practical uses contemplated. All such modifications and variations are within the scope of the invention as defined by the appended claims, interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.

Claims

1. When a sound resulting from a predetermined event (hereinafter referred to as an event sound) is included in the noise around the user, the user is made aware that the event is occurring. A noise suppression device, a situation identification result generating unit that generates a situation identification result indicating a likelihood that the event is occurring around the user from sensor data acquired using a sensor; an adjustment information generating unit that generates information (hereinafter referred to as adjustment information) regarding the relative volume of an event sound canceling sound that cancels the event sound with respect to a canceling sound that cancels the noise, which is determined in accordance with the value of the situation identification result; a cancellation sound signal generation unit that generates a cancellation sound signal that cancels the noise from the user's listening sound signal acquired using one or more microphones and the adjustment information, the value of the situation identification result is a value indicating a degree of correlation between a reference sound for determining whether a sound originates from a predetermined event and the noise; The adjustment information is information indicating that the larger the value of the situation identification result, the larger the proportion of the event sound erasing sound to be excluded from the erasing sound. Noise suppression device.

2. A noise suppression device that, when a sound resulting from a predetermined event (hereinafter referred to as an event sound) is included in noise around a user, makes the user aware that the event is occurring. A noise suppression method, comprising: a situation identification result generating step of generating a situation identification result indicating a likelihood that the event is occurring around the user from sensor data acquired using a sensor; an adjustment information generating step of generating information (hereinafter referred to as adjustment information) regarding the relative volume of an event sound canceling sound that cancels the event sound with respect to a canceling sound that cancels the noise, the information being determined in accordance with the value of the situation identification result; a cancellation sound signal generating step of generating a cancellation sound signal that cancels the noise from the user's listening sound signal acquired using one or more microphones and the adjustment information, the value of the situation identification result is a value indicating a degree of correlation between a reference sound for determining whether a sound originates from a predetermined event and the noise; The adjustment information is information indicating that the larger the value of the situation identification result, the larger the proportion of the event sound erasing sound to be excluded from the erasing sound. Noise suppression methods.

3. A program for causing a computer to function as the noise suppression device according to claim 1.

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