JP7586148B2 - Information processing device, method, and program - Google Patents

Description

This disclosure relates to an information processing device, method, and program.

Technologies related to sound field simulation are known in the past. For example, Patent Document 1 discloses a technology that calculates the reflection direction of a sound wave without taking into account a specific surface in order to speed up the calculation of the reflection direction of the sound wave in the analysis of the reflection path of the sound wave.

JP 2004-077352 A

In sound field simulations that reproduce sound fields, particularly large outdoor sound fields at the level of a city, in a virtual three-dimensional space, the amount of calculations required is enormous due to the presence of a wide variety of objects as sound sources. However, in the past, there was insufficient reduction in the amount of calculations required, and there was room for improvement in sound field simulation technology.

In light of these circumstances, the purpose of this disclosure is to improve technology related to sound field simulation.

An information processing device according to an embodiment of the present disclosure includes:
An information processing device including a control unit,
The control unit is
For a plurality of sound sources in a virtual three-dimensional space corresponding to a sound field, sound source data indicating a sound pressure level for each frequency of each sound source group is acquired based on recording data acquired in the sound field during an observation period, for the sound sources classified into a plurality of sound source groups.
setting a representative frequency band for each of the plurality of sound source groups according to a sound pressure level indicated by the acquired sound source data;
A sound is simulated that propagates through the virtual three-dimensional space from a sound source to be evaluated that is different from the sound sources classified into the plurality of sound source groups and reaches one observation point, and a sound is simulated that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group and reaches the one observation point, limited to a representative frequency band of each set sound source group.

According to one embodiment of the present disclosure, the method comprises:
A method executed by an information processing device, comprising:
acquiring sound source data indicating a sound pressure level for each frequency of each sound source group based on recording data acquired in the sound field during an observation period, for sound sources classified into a plurality of sound source groups among a plurality of sound sources in a virtual three-dimensional space corresponding to the sound field;
setting a representative frequency band of each of the plurality of sound source groups according to a sound pressure level indicated by the acquired sound source data; and simulating a sound that propagates through the virtual three-dimensional space from a sound source to be evaluated that is different from the sound sources classified into the plurality of sound source groups and reaches one observation point, and simulating a sound that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group and reaches the one observation point, limited to the representative frequency band of each of the set sound source groups.

A program according to an embodiment of the present disclosure includes:
In the information processing device,
acquiring sound source data indicating a sound pressure level for each frequency of each sound source group based on recording data acquired in the sound field during an observation period, for sound sources classified into a plurality of sound source groups among a plurality of sound sources in a virtual three-dimensional space corresponding to the sound field;
setting a representative frequency band of each of the plurality of sound source groups according to a sound pressure level indicated by the acquired sound source data; and simulating a sound that propagates through the virtual three-dimensional space from a sound source to be evaluated that is different from the sound sources classified into the plurality of sound source groups and reaches one observation point, and simulating a sound that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group and reaches the one observation point, limited to the representative frequency band of each of the set sound source groups.

According to one embodiment of the present disclosure, technology relating to sound field simulation is improved.

1 is a block diagram showing a schematic configuration of a system according to an embodiment of the present disclosure. FIG. 1 is a block diagram showing a schematic configuration of a recording apparatus. 1 is a block diagram showing a schematic configuration of an information processing device; 4 is a flowchart showing an operation of the information processing device. FIG. 1 is a diagram showing a specific example of a virtual three-dimensional space.

The following describes an embodiment of the present disclosure.

<Overview of the embodiment>
An overview of a system 1 according to an embodiment of the present disclosure will be described with reference to Fig. 1. The system 1 includes a recording device 10 and an information processing device 20. The recording device 10 and the information processing device 20 are communicatively connected to a network 30 including, for example, the Internet and a mobile communication network.

The recording device 10 is, for example, a sound recording device equipped with a microphone, but is not limited to this and may be any device. In this embodiment, the recording device 10 is installed in a sound field 40 in which multiple sound sources 41a, ..., 41n exist. In the following, the multiple sound sources 41a, ..., 41n may be collectively referred to as "multiple sound sources 41". In this embodiment, the sound field 40 is an outdoor sound field (e.g., a city square), but it may also be an indoor sound field (e.g., inside a factory building). The position in the sound field 40 where the recording device 10 is installed corresponds to one observation point in this embodiment. The number of recording devices 10 provided in the system 1 may be determined arbitrarily.

The information processing device 20 is, for example, a computer such as a server device. The information processing device 20 is capable of communicating with the recording device 10 via the network 30. The information processing device 20 receives acquired sound source data from the recording device 10 via the network 30.

First, an overview of this embodiment will be described, and details will be described later. The information processing device 20 acquires sound source data indicating the sound pressure level for each frequency acquired in the sound field 40 during an observation period for sound sources classified into multiple sound source groups among multiple sound sources 41 in a virtual three-dimensional space corresponding to a sound field. The information processing device 20 sets a representative frequency band for each of the multiple sound source groups according to the sound pressure level indicated by the acquired sound source data. The information processing device 20 simulates a sound that propagates through the virtual three-dimensional space from an evaluation target sound source 42 that is different from the sound sources classified into the multiple sound source groups and reaches one observation point, and also simulates a sound that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group and reaches one observation point, limited to the representative frequency band of each set sound source group.

In this way, according to this embodiment, the sound emitted by sound sources belonging to each sound source group, which are sound sources other than the sound source 42 to be evaluated, is limited to a representative frequency band, and the sound field 40 is simulated. Therefore, when reproducing a wide outdoor sound field at the level of a city, for example, in a virtual three-dimensional space, the amount of calculations for sounds emitted by sound sources other than the sound source 42 to be evaluated can be reduced. Therefore, technology related to sound field simulation is improved in that it becomes easier to suppress an increase in the amount of calculations while ensuring the reproducibility of the sound field.

Next, each component of System 1 will be described in detail.

<Configuration of Recording Device>
As shown in FIG. 2, the recording device 10 includes a sound source data acquisition unit 11 , a positioning unit 12 , a communication unit 13 , an input unit 14 , an output unit 15 , a storage unit 16 , and a control unit 17 .

The sound source data acquisition unit 11 is, for example, a microphone, but is not limited to this and may be any device. The microphone is a microphone of any recording method, such as monaural recording or stereo recording. Stereo recording includes binaural recording. Binaural recording is a recording method in which sound is recorded in a state where it reaches the eardrum using equipment such as a dummy head that reproduces the acoustic effects of a human head. When the binaural recording method is adopted, the sound source data acquisition unit 11 may be a microphone capsule incorporated into both ears of equipment such as a dummy head that mimics a human head, or an earphone-type microphone worn on both human ears.

The positioning unit 12 includes one or more devices that acquire location information of the recording device 10. Specifically, the positioning unit 12 includes, for example, a receiver compatible with the Global Positioning System (GPS), but is not limited to this and may include a receiver compatible with any satellite positioning system.

The communication unit 13 includes one or more communication interfaces that connect to the network 30. The communication interfaces correspond to mobile communication standards such as, but are not limited to, 4G (4th Generation) or 5G (5th Generation). In this embodiment, the recording device 10 communicates with the information processing device 20 via the communication unit 13 and the network 30.

The input unit 14 includes at least one input interface. The input interface is, for example, a physical key, a capacitance key, a pointing device, or a touch screen integral with a display. The input unit 14 accepts an operation to input data used in the operation of the recording device 10. The input unit 14 may be connected to the recording device 10 as an external input device instead of being provided in the recording device 10. As the connection interface, for example, an interface corresponding to a standard such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface) (registered trademark), or Bluetooth (registered trademark) can be used. The input unit 14 also includes any sensor module capable of acquiring information indicating the state of the sound field 40. The information indicating the state of the sound field 40 includes, for example, information indicating the position in the sound field 40 (hereinafter also referred to as the "sound emission position") and the distance from one observation point (hereinafter also referred to as the "sound reach distance") for each of the multiple sound sources 41. For example, the sensor module may include a camera, an infrared sensor, a distance sensor such as LiDAR (light detection and ranging), or a combination thereof.

The output unit 15 may include one or more output devices that output information to notify the user. Examples of the output devices include, but are not limited to, speakers that output information as audio, or displays that output information as images or videos. The output unit 15 may include an interface for connecting an external output device.

The storage unit 16 includes one or more memories. The memories are, for example, but not limited to, semiconductor memories, magnetic memories, or optical memories. Each memory included in the storage unit 16 may function, for example, as a main storage device, an auxiliary storage device, or a cache memory. The storage unit 16 stores any information used in the operation of the recording device 10. For example, the storage unit 16 may store system programs, application programs, embedded software, and the like. The information stored in the storage unit 16 may be updatable, for example, with information obtained from the network 30 via the communication unit 13.

The control unit 17 includes one or more processors, one or more programmable circuits, one or more dedicated circuits, or a combination of these. The processor is, for example, but is not limited to, a general-purpose processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), or a dedicated processor specialized for a specific process. The programmable circuit is, for example, but is not limited to, an FPGA (Field-Programmable Gate Array). The dedicated circuit is, for example, but is not limited to, an ASIC (Application Specific Integrated Circuit). The control unit 17 controls the operation of the entire recording device 10.

<Configuration of information processing device>
As shown in FIG. 3, the information processing device 20 includes a communication unit 21, an input unit 22, an output unit 23, a storage unit 24, and a control unit 25.

The communication unit 21 includes one or more communication interfaces that connect to the network 30. The communication interface corresponds to, for example, a mobile communication standard, a wired LAN (Local Area Network) standard, or a wireless LAN standard, but is not limited to these, and may correspond to any communication standard. In this embodiment, the information processing device 20 communicates with the recording device 10 via the communication unit 21 and the network 30. Note that the information processing device 20 may communicate with one or more of the multiple sound sources in the virtual three-dimensional space according to this embodiment via the communication unit 21, via the network 30 or directly.

The input unit 22 includes at least one input interface. The input interface is, for example, a physical key, a capacitive key, a pointing device, or a touch screen that is integral with a display. The input unit 22 accepts an operation to input data used in the operation of the information processing device 20. Instead of being provided in the information processing device 20, the input unit 22 may be connected to the information processing device 20 as an external input device. As the connection interface, for example, an interface compatible with standards such as USB, HDMI (registered trademark), or Bluetooth (registered trademark) can be used.

The output unit 23 may include one or more output devices that output information to notify the user. Examples of the output devices include, but are not limited to, speakers that output information as audio, or displays that output information as images or videos. The output unit 23 may include an interface for connecting an external output device.

The storage unit 24 includes one or more memories. Each memory included in the storage unit 24 may function, for example, as a main storage device, an auxiliary storage device, or a cache memory. The storage unit 24 stores any information used in the operation of the information processing device 20. For example, the storage unit 24 may store system programs, application programs, databases, map information, and the like. The information stored in the storage unit 24 may be updatable, for example, with information obtained from the network 30 via the communication unit 21.

The control unit 25 includes one or more processors, one or more programmable circuits, one or more dedicated circuits, or a combination of these. The control unit 25 controls the operation of the entire information processing device 20.

In this embodiment, a sound source database is stored in the storage unit 24 of the information processing device 20. The sound source database stores sound source data indicating the sound pressure level for each frequency acquired in the sound field 40 during the observation period for sound sources classified into multiple sound source groups.

In the sound source database, each sound source is classified into a corresponding sound source group. The granularity of the sound source classification can be set arbitrarily, but in this embodiment, it is set roughly from the viewpoint of reducing the amount of calculation. For example, the control unit 25 of the information processing device 20 may set sound source groups of "vehicles", "bicycles", "people", and "natural sounds". "Natural sounds" is a sound source group to which sounds such as wind and rain belong. On the other hand, from the viewpoint of reproducibility of the sound field 40, the finer the granularity of the sound source classification, the more preferable it is. For example, the sound source group "people" may be subdivided by age or gender (such as "children" and "adults" or "males" and "females"). However, since the amount of calculation tends to increase as the classification is subdivided, the granularity of the sound source classification can be appropriately determined taking into consideration the balance between the reproducibility of the sound field 40 and the amount of calculation. Then, the control unit 25 classifies each sound source into one of the set sound source groups, and stores information in which each sound source is flagged to indicate the sound source group to which it belongs in the sound source database, thereby classifying each sound source into the corresponding sound source group.

For each sound source group set in this way, sound source data representative of the sound source group is created. Any method can be adopted for creating the sound source data. For example, the control unit 17 of the recording device 10 may convert the signal input to the sound source data acquisition unit 11 during the observation period into analog digital to create recording data representing the sounds emitted from each of the multiple sound sources 41. The control unit 17 may transmit the recording data of each sound source to the communication unit 21 of the information processing device 20 via the network 30 and the communication unit 13. The control unit 25 of the information processing device 20 may accumulate the recording data of each sound source in the sound source database as a sound sample of the sound source group to which each sound source belongs each time the recording data of each sound source is received via the communication unit 21. Then, the control unit 25 may create sound source data of each sound source group based on an experiment using the sound sample of each sound source group. As an experiment, for example, the control unit 25 may output a plurality of sound samples accumulated for a certain sound source group via the output unit 23. The user (experiment participant) may compare each sound sample with the sound heard in the actual sound field 40, identify the sound sample that is closest to the sound heard in the sound field 40, and input the identification information of the identified sound sample to the information processing device 20 via the input unit 22. The control unit 25 stores the sound sample identified by the input identification information in the sound source database as sound source data of the corresponding sound source group. By repeating this experiment for each sound source group, sound source data for each sound source group can be created and stored in the sound source database. When the granularity of the sound source classification is coarse as in this embodiment, the sound source data of each sound source group indicates a typical sound of the sound source included in that sound source group. For example, when various models of bicycles from different manufacturers belong to one sound source group "bicycles", the sound of the sound source group indicates a typical sound of various bicycles.

In this way, for sound sources classified into multiple sound source groups, sound source data indicating the sound pressure level for each frequency of each sound source group is created based on the recording data acquired in the sound field 40 during the observation period, and stored in the sound source database. Each time the control unit 25 executes the operation of FIG. 4 described below, it can obtain the sound source data used in the simulation of the sound field 40 by searching the sound source database using the sound source group as a query.

<Operation flow of information processing device>
The operation of the information processing device 20 according to the present embodiment will be described with reference to Fig. 4. The operation of Fig. 4 corresponds to a method according to the present embodiment. The operation of Fig. 4 is repeatedly executed, for example, at a predetermined cycle. The predetermined cycle can be arbitrarily determined.

Step S100: The control unit 25 of the information processing device 20 acquires sound source data indicating the sound pressure level for each frequency of each sound source group based on the recording data acquired in the sound field 40 during the observation period for the sound sources classified into multiple sound source groups among the multiple sound sources in the virtual three-dimensional space corresponding to the sound field 40.

Specifically, first, the control unit 25 creates a virtual three-dimensional space corresponding to the sound field 40. Any method can be adopted to create the virtual three-dimensional space. For example, the control unit 25 receives the first information and the second information from the communication unit 13 of the recording device 10 via the network 30 and the communication unit 21. The first information is position information indicating the position in the sound field 40 where the recording device 10 is installed, that is, the position of one observation point according to this embodiment, acquired via the positioning unit 12 of the recording device 10. The second information is information indicating the situation of the sound field 40, specifically, position information of the multiple sound sources 41 (i.e., information indicating the emission position of the sound), acquired via the input unit 14 of the recording device 10. The control unit 25 calculates the distance (i.e., the reach of the sound) from one observation point for each of the multiple sound sources 41 based on the first information and the second information. In this embodiment, the emission position and the reach of the sound are calculated from three-dimensional coordinates, but any method can be adopted without being limited to this. The control unit 25 creates a virtual three-dimensional space corresponding to the sound field 40 based on the position of one observation point and the calculated sound emission position and sound arrival distance. For example, the control unit 25 may create a virtual three-dimensional space VS as shown in FIG. 5. Point P corresponds to one observation point in this embodiment. Sound sources 41a, 41b, and 41c correspond to multiple sound sources in this embodiment.

Next, the control unit 25 refers to the sound source database stored in the storage unit 24 and selects multiple sound sources to be used in the simulation to reproduce the sound field 40. In the example shown in FIG. 5, multiple sound sources including sound source 41a (automatic driving vehicle), sound source 41b (road bike), and sound source 41c (man) are selected as the sound sources to be used in the simulation. The control unit 25 identifies a sound source group corresponding to each sound source. In the example shown in FIG. 5, "vehicle" is identified as the sound source group of sound source 41a, "bicycle" is identified as the sound source group of sound source 41b, and "person" is identified as the sound source group of sound source 41c. As described above, the sound source database accumulates sound source data indicating the sound pressure level for each frequency of each sound source group, which was created based on the recording data acquired in the sound field 40 during the observation period, for the sound sources classified into multiple sound source groups among the multiple sound sources 41 in the virtual three-dimensional space corresponding to the sound field 40. Therefore, the control unit 25 can obtain sound source data for each sound source in the virtual three-dimensional space by searching the sound source database using the identified sound source group as a query. In the example shown in FIG. 5, sound source data is obtained for each sound source, including sound sources 41a, 41b, and 41c, in the virtual three-dimensional space VS.

In this way, the control unit 25 acquires sound source data indicating the sound pressure level for each frequency of each sound source group for the sound sources classified into multiple sound source groups out of the multiple sound sources in the virtual three-dimensional space corresponding to the sound field 40, based on the recording data acquired in the sound field 40 during the observation period. In this way, sound source data for each sound source other than the evaluation target sound source 42, which is used in the simulation of reproducing the sound field 40, is acquired. In addition to the multiple sound sources 41, the sound source database may also store and acquire sound source data for sounds (described later) other than the artificial sound of the evaluation target sound source 42, which was acquired in the sound field 40 during the observation period. However, the acquisition of sound source data is not limited to these examples and any method can be adopted.

Step S101: The control unit 25 sets a representative frequency band for each of the multiple sound source groups according to the sound pressure level indicated by the sound source data acquired in step S100.

Specifically, the control unit 25 refers to the sound source database stored in the storage unit 24 and extracts a characteristic frequency band from the entire frequency range of the sound source data of each sound source group for each sound source group set in step S100. The control unit 25 sets the extracted frequency band as the representative frequency band of each sound source group. Any method can be adopted for extracting the characteristic frequency band. For example, the control unit 25 searches the sound source database and refers to the sound pressure level for each frequency indicated in the sound source data of a certain sound source group. Then, the control unit 25 may set a predetermined range of frequencies centered on a frequency at which a peak of the sound pressure level appears as the characteristic frequency band of the sound source group. In the example shown in FIG. 5, the control unit 25 refers to the sound pressure level for each frequency indicated in the sound source data for the sound source group "vehicle" to which the sound source 41a belongs. Then, the control unit 25 may set a predetermined range of frequencies centered on a frequency at which a peak of the sound pressure level appears as the characteristic frequency band of the sound source group "vehicle". The predetermined range can be set arbitrarily, but a specific example is shown below.

5 shows two graphs with sound pressure on the vertical axis and frequency on the horizontal axis. The graph on the right plots the sound pressure level values for each frequency indicated by the sound source data of the sound source group "vehicle" to which the sound source 41a belongs. When comparing the sound pressure level of the frequency band corresponding to the right half of the graph (hereinafter also referred to as the "higher frequency band") with the sound pressure level of the frequency band corresponding to the left half of the graph (hereinafter also referred to as the "lower frequency band"), a peak in the sound pressure level appears in the lower frequency band (hatched range). Therefore, the control unit 25 can set the lower frequency band as the characteristic frequency band of the sound source group "vehicle". Note that the boundary between the frequency bands can be set, for example, as a frequency that is a predetermined decibel (dB) lower than the maximum sound pressure level. The graph on the left plots the sound pressure level values for each frequency indicated by the sound source data of the sound source group "bicycle" to which the sound source 41b belongs. When comparing the sound pressure level of the higher frequency band with the sound pressure level of the lower frequency band, a peak in the sound pressure level appears in the higher frequency band (hatched area). Therefore, the control unit 25 can set the higher frequency band as the characteristic frequency band of the sound source group "bicycle." For convenience of illustration, the graph for sound source 41c is omitted, but a characteristic frequency band can be set in the same way as for sound sources 41a and 41b.

In this way, the control unit 25 sets the representative frequency band of each of the multiple sound source groups according to the sound pressure level indicated by the acquired sound source data.

Step S102: The control unit 25 simulates a sound that propagates through a virtual three-dimensional space from an evaluation target sound source 42, which is a sound source that is different from the sound sources classified into the multiple sound source groups among the multiple sound sources 41, and reaches one observation point.

In this embodiment, the sound source 42 to be evaluated is a robot that emits artificial sounds and sounds other than artificial sounds. In the example shown in FIG. 5, the robot that is the sound source 42 to be evaluated is an automatic transport robot located at point Q in the virtual three-dimensional space VS. However, the robot is not limited to this and may be any robot. The control unit 25 simulates the sound created for the robot as an artificial sound. In the example shown in FIG. 5, the control unit 25 simulates the sound S0 created for the automatic transport robot as an artificial sound, as a sound that propagates from the automatic transport robot located at point Q through the virtual three-dimensional space VS to reach one observation point. In this embodiment, the artificial sound is a sound that makes it easier for humans to understand the behavior of the robot (e.g., starting, stopping, turning direction, etc.), but is not limited to this and may include, for example, a synthetic voice that imitates a human voice. Any method can be used to create the artificial sound. For example, the artificial sound may be a melody created based on a tone that is easily noticeable to humans based on mathematical calculations.

When simulating sounds created for a robot as artificial sounds, it is desirable to simulate multiple artificial sounds. The more artificial sounds that are simulated, the more clues there are to determine what kind of sounds the robot should emit to humans in the actual sound field 40 to ensure safety (for example, sounds that make it easier for humans to notice the robot's approach). As a result, it becomes easier to increase the reliability of the artificial sound simulation. Furthermore, it is desirable to take into account the influence of sounds other than the artificial sounds emitted by the robot (for example, the sound of the robot running or the sound of the refrigeration system). If a sound field simulation is performed that takes into account the influence of sounds other than the artificial sounds, the reproducibility of the sound field 40 will be improved, and the higher the reproducibility of the sound field 40, the easier it will be to identify the frequencies of artificial sounds that are easily understood by humans in the actual sound field 40.

Therefore, when simulating a sound created for a robot as an artificial sound, the control unit 25 may simulate multiple artificial sounds and sounds other than artificial sounds, and evaluate the degree of discriminability of each artificial sound at one observation point.

In addition, when simulating a sound propagating from the sound source 42 to be evaluated in the virtual three-dimensional space and reaching an observation point, the control unit 25 may calculate the distance attenuation of the sound. Specifically, the control unit 25 may apply the calculated distance attenuation to data representing the artificial sound and the sound other than the artificial sound propagating from the robot, which is the sound source 42 to be evaluated, in the virtual three-dimensional space and reaching an observation point, to simulate the artificial sound and the sound other than the artificial sound. Any method may be used to calculate the distance attenuation. For example, the control unit 25 may calculate an estimate of the attenuation due to air absorption based on predetermined conditions including the frequency and the environmental conditions of the sound field 40 (temperature distribution, temperature and humidity, wind direction, etc.). The control unit 25 may calculate the distance attenuation of the sound emitted from the robot by applying the calculated estimate to the data representing the sound.

Step S103: The control unit 25 simulates the sound that propagates through the virtual three-dimensional space from the sound sources belonging to each sound source group and reaches one observation point, limited to the representative frequency band of each sound source group set in step S101.

Specifically, the control unit 25 excludes from the calculation the parts of the sound source data of each sound source group to which each of the multiple sound sources 41 in the virtual three-dimensional space belongs that correspond to frequencies other than the representative frequency band, and calculates only the parts that correspond to the representative frequency band. In other words, the parts of the sound source data of each sound source group that are used to simulate the sound that propagates through the virtual three-dimensional space from the sound sources belonging to each sound source group and reaches one observation point are limited to the parts that correspond to the representative frequency band set in step S101. For example, for the sound source 41a shown in FIG. 5, the control unit 25 simulates the sound S1 created using only the parts of the sound source data of the sound source group "vehicle" that correspond to the lower frequency band as the sound of the sound source 41a. For the sound source 41b, the control unit 25 simulates the sound S2 created using only the parts of the sound source data of the sound source group "bicycle" that correspond to the higher frequency band as the sound of the sound source 41b. For convenience, the sound source 41c is not shown in the figure, but the sound of the sound source 41c can also be simulated by limiting it to a representative frequency band.

For ease of explanation, step S103 is described as being executed after step S102, but steps S102 and S103 may be executed in the reverse order or simultaneously. After steps S102 and S103, the process ends.

In this way, the control unit 25 simulates sound that propagates through the virtual three-dimensional space from the evaluation target sound source 42 that is different from the sound sources classified into multiple sound source groups and reaches one observation point, and also simulates sound that propagates through the virtual three-dimensional space from the sound sources belonging to each sound source group and reaches one observation point, limited to the representative frequency band of each set sound source group. This makes it possible to perform a sound field simulation by limiting the frequency band for the sound sources classified into multiple sound source groups, and without limiting the frequency band for the evaluation target sound source 42. As a result, it becomes easier to realize a sound field simulation that takes into account the balance between reducing the amount of calculation and reproducibility of the sound field.

The distinguishability of the artificial sound mentioned in step S102 refers to the ease of understanding the fact of reproduction of the artificial sound and the intended intention when an artificial sound is reproduced in a sound field 40 in which multiple sound sources 41 exist. Any method can be adopted for evaluating the distinguishability of the artificial sound. For example, while reproducing sounds other than the artificial sound emitted by the robot and sounds of the sound sources belonging to each sound source group, a sample of the artificial sound is reproduced randomly for a user (experiment participant) who is working, and an experiment is repeated to investigate the degree to which the user understands the fact of reproduction of the sample and the intended intention. The user scores the distinguishability of each sample. For example, the shorter the time it takes for the user to notice the reproduction of each sample, or the higher the degree of understanding of the intended intention of each sample, the higher the score may be given. The score compilation result may be stored in the sound source database as information linking each sample of the artificial sound with the score. Based on the compilation result stored in the sound source database, the control unit 25 may extract, for example, the sample with the highest total score as the most distinguishable sample. The control unit 25 may output the extracted samples to the user via the output unit 23. In this way, when simulating the sound created for the robot as an artificial sound, the control unit 25 can simulate multiple artificial sounds and sounds other than artificial sounds and evaluate the degree of discriminability of each artificial sound at one observation point. As a result, it becomes easier to identify sounds that are more likely to ensure human safety as sounds that are expressed by the robot to humans in the actual sound field 40.

As described above, the information processing device 20 according to this embodiment acquires sound source data indicating the sound pressure level for each frequency acquired in the sound field 40 during an observation period for sound sources classified into multiple sound source groups among multiple sound sources 41 in a virtual three-dimensional space corresponding to a sound field. The information processing device 20 sets a representative frequency band for each of the multiple sound source groups according to the sound pressure level indicated by the acquired sound source data. The information processing device 20 simulates a sound that propagates through the virtual three-dimensional space from an evaluation target sound source 42 that is different from the sound sources classified into the multiple sound source groups and reaches one observation point, and also simulates a sound that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group and reaches one observation point, limited to the representative frequency band of each set sound source group.

According to this configuration, the sound field 40 is simulated by limiting the sound emitted by sound sources belonging to each sound source group, which are sound sources other than the sound source 42 to be evaluated, to a representative frequency band. Therefore, when reproducing a wide outdoor sound field at the level of a city, for example, in a virtual three-dimensional space, the amount of calculations for the sound emitted by sound sources other than the sound source 42 to be evaluated can be reduced. This improves the technology related to sound field simulation in that it becomes easier to suppress an increase in the amount of calculations while ensuring the reproducibility of the sound field.

Although the present disclosure has been described based on the drawings and examples, it should be noted that a person skilled in the art may make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included in the scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined into one or divided.

For example, in the above-described embodiment, the configuration and operation of the information processing device 20 may be distributed among multiple computers that can communicate with each other. Also, for example, an embodiment in which some or all of the components of the information processing device 20 are provided in the recording device 10 may be possible.

In addition, for example, an embodiment is also possible in which a general-purpose computer functions as the information processing device 20 according to the above-described embodiment. Specifically, a program describing the processing contents for realizing each function of the information processing device 20 according to the above-described embodiment is stored in the memory of the general-purpose computer, and the program is read and executed by a processor. Thus, the present disclosure can also be realized as a program executable by a processor, or a non-transitory computer-readable medium that stores the program.

REFERENCE SIGNS LIST 1 System 10 Recording device 11 Sound source data acquisition unit 12 Positioning unit 13 Communication unit 14 Input unit 15 Output unit 16 Memory unit 17 Control unit 20 Information processing device 21 Communication unit 22 Input unit 23 Output unit 24 Memory unit 25 Control unit 30 Network 40 Sound field 41 Multiple sound sources 41a Self-driving vehicle 41b Road bike 41c Man 42 Sound sources to be evaluated P, Q Points S0, S1, S2 Sound VS Virtual three-dimensional space

Claims (5)

An information processing device including a control unit,
The control unit is
For a plurality of sound sources in a virtual three-dimensional space corresponding to a sound field, sound source data indicating a sound pressure level for each frequency of each sound source group is acquired based on recording data acquired in the sound field during an observation period, for the sound sources classified into a plurality of sound source groups.
setting a representative frequency band for each of the plurality of sound source groups according to a sound pressure level indicated by the acquired sound source data;
an information processing device that simulates a sound that propagates through the virtual three-dimensional space from a sound source to be evaluated that is different from the sound sources classified into the plurality of sound source groups and reaches one observation point, and that simulates a sound that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group, limited to a representative frequency band of each set sound source group, and reaches the one observation point. 2. The information processing device according to claim 1,
the evaluation target sound source is a robot that emits an artificial sound and a sound other than an artificial sound,
The control unit is an information processing device that simulates a sound created for the robot as the artificial sound. 3. The information processing device according to claim 2,
the control unit, when simulating the sound created for the robot as the artificial sound, further includes simulating a plurality of artificial sounds and sounds other than the artificial sounds, and evaluating a level of discriminability of each artificial sound at the one observation point. A method executed by an information processing device, comprising:
acquiring sound source data indicating a sound pressure level for each frequency of each sound source group based on recording data acquired in the sound field during an observation period, for sound sources classified into a plurality of sound source groups among a plurality of sound sources in a virtual three-dimensional space corresponding to the sound field;
setting a representative frequency band for each of the plurality of sound source groups according to a sound pressure level indicated by the acquired sound source data; and simulating a sound that propagates through the virtual three-dimensional space from a sound source to be evaluated that is different from the sound sources classified into the plurality of sound source groups and reaches one observation point, and simulating a sound that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group and reaches the one observation point, limited to the representative frequency band of each of the set sound source groups. In the information processing device,
acquiring sound source data indicating a sound pressure level for each frequency of each sound source group based on recording data acquired in the sound field during an observation period, for sound sources classified into a plurality of sound source groups among a plurality of sound sources in a virtual three-dimensional space corresponding to the sound field;
setting a representative frequency band of each of the plurality of sound source groups according to a sound pressure level indicated by the acquired sound source data; and simulating a sound that propagates through the virtual three-dimensional space from a sound source to be evaluated that is different from the sound sources classified into the plurality of sound source groups and reaches one observation point, and simulating a sound that propagates through the virtual three-dimensional space from a sound source belonging to each sound source group and reaches the one observation point, limited to the representative frequency band of each of the set sound source groups.

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