JP7559809B2 - Sound environment simulator and sound environment simulation method - Google Patents

Description

This disclosure relates to simulating a sound environment.

Patent Document 1 discloses a technique for performing geometric acoustic simulation to analyze the acoustic characteristics of a sound field of a building. The inner product of the normal vector of a surface involved in the reflection of a sound wave and each of a predetermined number of reference vectors is calculated. Depending on the combination of signs of the inner product, the surfaces involved in the reflection are classified into a number of groups. When calculating the reflection direction of a sound wave, the inner product of the sound ray vector of the sound wave and each of the above-mentioned multiple reference vectors is calculated. The reflection direction is calculated without considering surfaces classified into a predetermined group that should be excluded from the candidates determined according to the combination of signs of the inner product.

JP 2004-077352 A

In simulating a sound environment, it is desirable to reproduce the sounds heard at the observation point with high accuracy. To achieve this, it is preferable to consider not only the direct sound from the sound source to the observation point, but also the reflected sound that is reflected by objects and reaches the observation point. However, in the real world, there are many objects around the sound source and observation point, and many reflected sounds often reach the observation point. If a simulation is performed taking all reflected sounds into account, the processing load will be enormous. This is undesirable from the perspective of computer resources and costs.

One objective of the present disclosure is to provide a technology that can reduce the processing load while ensuring the accuracy of the sound environment simulation.

The first aspect relates to a sound environment simulator that simulates a sound environment in a target world.
The sound environment simulator is
one or more processors;
The device comprises one or more storage devices that store world configuration information indicating at least the positions of sound sources and reflecting objects in the target world.
The reflection path is the path of a reflected sound that is output from a sound source, reflected by any reflecting object, and reaches an observation point.
The one or more processors
Based on the world configuration information, reflecting objects capable of forming a reflection path for a combination of a sound source and an observation point are extracted as simulation candidates;
Calculate an evaluation value for each simulation candidate based on the world configuration information, the evaluation value increasing as the reflection path length decreases;
Selecting at least one simulation candidate as a representative reflecting object based on the evaluation value;
The sound propagation characteristics along the reflection path formed by the representative reflecting object are simulated without using any reflecting object other than the representative reflecting object.

The second aspect relates to a sound environment simulation method for simulating a sound environment in a target world by a computer.
The world configuration information indicates at least the positions of sound sources and reflecting objects in the target world.
The reflection path is the path of a reflected sound that is output from a sound source, reflected by any reflecting object, and reaches an observation point.
The sound environment simulation method is as follows:
Extracting, as simulation candidates, reflective objects capable of forming a reflection path for a combination of a sound source and an observation point based on the world configuration information;
calculating an evaluation value for each of the simulation candidates based on the world configuration information, the evaluation value increasing as the length of the reflection path decreases;
selecting at least one of the simulation candidates as a representative reflecting object based on the evaluation value;
The method includes simulating sound propagation characteristics along a reflection path formed by the representative reflecting object without using any reflecting object other than the representative reflecting object.

According to the present disclosure, a representative reflecting object is selected based on the evaluation value. Then, only the selected representative reflecting object is used in the simulation, rather than all reflecting objects. This makes it possible to reduce the processing load while ensuring simulation accuracy.

FIG. 1 is a conceptual diagram for outlining a sound environment simulator according to an embodiment. FIG. 1 is a conceptual diagram for explaining direct sound and reflected sound. 1 is a schematic diagram for explaining an overview of a simulation of reflected sound according to an embodiment; FIG. 2 is a conceptual diagram for explaining an outline of a simulation of reflected sound according to an embodiment. FIG. 11 is a conceptual diagram for explaining a first example of an evaluation value according to the embodiment. FIG. 11 is a conceptual diagram for explaining a second example of an evaluation value according to the embodiment. 10A and 10B are conceptual diagrams for explaining examples of targets to be excluded from the sound environment simulation according to the embodiment. 1 is a block diagram showing an example of the configuration of a sound environment simulator according to an embodiment; 1 is a flowchart illustrating an outline of a sound environment simulation process according to an embodiment.

An embodiment of the present disclosure will be described with reference to the attached drawings.

1 is a conceptual diagram for explaining an overview of a sound environment simulator 100 according to an embodiment. The sound environment simulator 100 simulates a sound environment in a target world 1. Examples of the target world 1 include a city, a building, the site of a facility, and the like.

There are various sound sources 10 in the target world 1. The sound sources 10 may be moving objects or stationary objects. Examples of moving sound sources 10 include vehicles, robots, flying objects, etc. The vehicle may be an autonomous vehicle or a vehicle driven by a driver. Examples of robots include logistics robots, cleaning robots, and work robots. The robot may issue voice messages to communicate with humans. Examples of flying objects include drones, etc. Examples of stationary sound sources 10 include street vision, speakers, alarms, etc. Note that the sound sources 10 are not particularly limited.

The sound environment simulator 100 simulates, for example, how a sound sounds at an observation point 20 in the target world 1. For example, the observation point 20 is the position of a human (listener). As another example, the observation point 20 is the position of a robot that performs sound recognition. Note that the observation point 20 is not particularly limited.

As shown in FIG. 2, the sound that arrives at the observation point 20 from the sound source 10 is classified into "direct sound Sd (direct wave)" and "reflected sound Sr (reflected wave)." Direct sound Sd is sound that arrives directly from the sound source 10 to the observation point 20 without reflection. The direct path Pd is the path of the direct sound Sd.

On the other hand, the reflected sound Sr is a sound that is output from the sound source 10, reflected by one of the reflecting objects 30, and reaches the observation point 20. The reflecting objects 30 are various objects that exist in the target world 1. Examples of the reflecting objects 30 include walls, boards, ceilings, floors, ground, structures, and moving objects (e.g., vehicles and robots). The reflecting objects 30 are not particularly limited. The reflection path Pr is the path of the reflected sound Sr. In other words, the reflection path Pr is a combination of the path from the sound source 10 to the reflecting object 30 and the path from the reflecting object 30 to the observation point 20. The reflection path Pr can be calculated geometrically based on the positional relationship between the sound source 10, the observation point 20, and the reflecting object 30.

In a sound environment simulation, it is desirable to reproduce the sound heard at the observation point 20 with high accuracy. To that end, the sound environment simulator 100 performs a sound environment simulation taking into account not only the direct sound Sd but also the reflected sound Sr. In other words, the sound environment simulation includes a simulation of the sound propagation characteristics of the reflected sound Sr along the reflection path Pr.

The number of sound sources 10 considered in the sound environment simulation may be two or more. If the sound source 10 has directionality, the direction in which sound is output from the sound source 10 is taken into account in the sound environment simulation.

To reduce the processing load, multiple reflections (more than two) can be ignored, and only "early reflections" that are reflected once can be considered. Even if only early reflections are considered, sufficient simulation accuracy can be obtained.

As a result of the sound environment simulation, the sound intensity and the direction from which the sound comes at the observation point 20 can be known. In addition, the delay from the direct sound Sd to the reflected sound Sr at the observation point 20 can be known. Such a delay reflects the expansion of the space. Therefore, based on the delay characteristics, it is possible to understand, for example, how a person at the observation point 20 perceives the space. Furthermore, it is also possible to know the material-dependent filter effect of the reflecting object 30, i.e., how the waveform of the reflected sound Sr changes.

Such sound environment simulation is useful for designing the target world 1. For example, if the target world 1 is a town such as a smart city, there is a need to design a town that is more comfortable for people. For example, there may be scenes in which audio information needs to be transmitted to people, such as announcements at stations or in the city, or conversations between robots and humans. In such scenes, the audio information may not be transmitted to people properly due to the surrounding environment. If problems with audio transmission can be identified in advance through sound environment simulation, measures to solve the problem can be taken and fed back into the design. For example, the material and arrangement of components in the city (e.g., walls) can be changed so that problems with audio transmission are eliminated. As another example, if it is found that a certain frequency of sound is easily absorbed, it may be possible to consider refraining from outputting that particular frequency of sound from the sound source 10.

Sound is also one of the important factors that affect human behavior. Therefore, sound environment simulation is also useful for simulating human behavior in the target world 1. The results of simulating human behavior in the target world 1 can also be fed back into the design of the target world 1.

There is also known technology that collects information from the real world and reproduces the state of the real world in a virtual world in real time. This technology is also called a digital twin. This digital twin can also be used to predict the future state of the target world 1. In this case, by predicting human behavior based on the results of a sound environment simulation, it becomes possible to predict the future state of the target world 1 with higher accuracy.

2. Reducing the processing load of sound environment simulation 2-1. Overview As described above, in sound environment simulation, it is desirable to accurately reproduce the sound heard at the observation point 20. To achieve this, it is preferable to consider not only the direct sound Sd from the sound source 10 to the observation point 20 but also the reflected sound Sr. However, in the real world, there are many reflecting objects 30 around the sound source 10 and the observation point 20, and many reflected sounds Sr often reach the observation point 20. If a simulation is performed taking all the reflected sounds Sr into account, the processing load becomes enormous. This is not preferable from the viewpoint of computer resources and costs.

Therefore, according to this embodiment, the reflected sounds Sr considered in the sound environment simulation are limited to a small number. As described above, the reflected sound Sr is a sound that is output from the sound source 10, reflected by one of the reflecting objects 30, and reaches the observation point 20, and the reflection path Pr is the path of the reflected sound Sr. Therefore, the reflecting object 30, the reflection path Pr, and the reflected sound Sr correspond one-to-one and can be said to be equivalent. Limiting the reflected sounds Sr considered in the sound environment simulation to a small number means limiting the reflection paths Pr and reflecting objects 30 considered in the sound environment simulation to a small number.

Below, an overview of the simulation of the reflected sound Sr in this embodiment will be explained with reference to Figures 3 and 4.

Since there are many reflecting objects 30 around the sound source 10 and the observation point 20, many reflection paths Pr can be formed for one combination of the sound source 10 and the observation point 20. Hereinafter, the reflecting objects 30 that can form a reflection path Pr for the combination of the sound source 10 and the observation point 20 are referred to as "simulation candidates." The sound environment simulator 100 provisionally extracts the simulation candidates.

The sound environment simulator 100 then calculates an "evaluation value Q" for each of the extracted simulation candidates. The evaluation value Q represents the degree of contribution to the sound intensity (sound pressure) at the observation point 20. Therefore, the evaluation value Q depends at least on the length of the reflection path Pr from the sound source 10 to the observation point 20. Specifically, the shorter the length of the reflection path Pr formed by a certain reflecting object 30, the higher the evaluation value Q of that reflecting object 30. Conversely, the longer the reflection path Pr formed by a certain reflecting object 30, the shorter the evaluation value Q of that reflecting object 30. Various examples of the evaluation value Q will be described later.

The sound environment simulator 100 selects at least one simulation candidate as a "representative reflecting object 30-X" based on the evaluation value Q. More specifically, the sound environment simulator 100 selects a simulation candidate with a relatively high evaluation value Q as the representative reflecting object 30-X. The number of selected representative reflecting objects 30-X may be one. In other words, the sound environment simulator 100 may select only one simulation candidate with a relatively high evaluation value Q as the representative reflecting object 30-X. Typically, the sound environment simulator 100 selects at least one simulation candidate with the highest evaluation value Q as the representative reflecting object 30-X. The sound environment simulator 100 may select only one simulation candidate with the highest evaluation value Q as the representative reflecting object 30-X.

The "representative reflected sound Sr-X" is the reflected sound Sr reflected by the representative reflecting object 30-X. The "representative reflected path Pr-X" is the reflected path Pr formed by the representative reflecting object 30-X. The representative reflecting object 30-X, the representative reflected path Pr-X, and the representative reflected sound Sr-X correspond one-to-one and can be said to be equivalent. Selecting the representative reflecting object 30-X means selecting the representative reflected sound Sr-X or the representative reflected path Pr-X.

The sound environment simulator 100 simulates the sound propagation characteristics of the representative reflected sound Sr-X along the representative reflection path Pr-X. At this time, the sound environment simulator 100 uses only the selected representative reflecting object 30-X (representative reflected sound Sr-X, representative reflection path Pr-X) and does not use any others. In other words, objects other than the representative reflecting object 30-X (representative reflected sound Sr-X, representative reflection path Pr-X) are excluded from the simulation. The sound environment simulator 100 simulates the sound propagation characteristics of the representative reflected sound Sr-X along the representative reflection path Pr-X using only the representative reflecting object 30-X, without using any reflecting object 30 other than the representative reflecting object 30-X.

The inventors of the present application have confirmed through experiments that the way in which actual sounds are heard can be reproduced quite accurately even by a sound environment simulation using only the representative reflecting object 30-X. In other words, the inventors of the present application have confirmed that the accuracy of the sound environment simulation can be ensured even when only the representative reflecting object 30-X is used.

In this way, according to this embodiment, a representative reflecting object 30-X is selected based on the evaluation value Q. Then, instead of all reflecting objects 30, only the selected representative reflecting object 30-X is used in the sound environment simulation. This makes it possible to reduce the processing load while ensuring the accuracy of the sound environment simulation. As a result, computer resources and costs are also reduced. The effect is even greater when there is only one representative reflecting object 30-X.

2-2. Examples of Evaluation Values Below, various examples of the evaluation value Q will be described. For simplicity, multiple reflections (two or more times) are not considered, and only early reflections (early reflections) that are reflected only once are taken into consideration.

5 is a conceptual diagram for explaining a first example of the evaluation value Q. The evaluation value Q depends on the length Lp of the reflection path Pr from the sound source 10 to the observation point 20. That is, as expressed by the following formula (1), the evaluation value Q is expressed as a function of the length Lp of the reflection path Pr.

Formula (1): Q=f(Lp)

More specifically, the shorter the length Lp of the reflection path Pr, the higher the evaluation value Q. In the example shown in FIG. 5, the length Lp-1 of the first reflection path Pr-1 formed by the first reflecting object 30-1 is shorter than the length Lp-2 of the second reflection path Pr-2 formed by the second reflecting object 30-2. Therefore, the evaluation value Q of the first reflecting object 30-1 is higher than the evaluation value Q of the second reflecting object 30-2.

2-2-2. Second Example FIG. 6 is a conceptual diagram for explaining a second example of the evaluation value Q. In the example shown in FIG. 6, the length Lp-1 of the first reflection path Pr-1 formed by the first reflecting object 30-1 and the length Lp-2 of the second reflection path Pr-2 formed by the second reflecting object 30-2 are equal. However, the distance Da-1 from the sound source 10 to the first reflecting object 30-1 along the first reflection path Pr-1 is shorter than the distance Da-2 from the sound source 10 to the second reflecting object 30-2 along the second reflection path Pr-2. In this case, the evaluation value Q of the first reflecting object 30-1 may be set higher than the evaluation value Q of the second reflecting object 30-2. This is because the first reflecting object 30-1, which is closer to the sound source 10, can reflect more sound waves toward the observation point 20.

Generalized as follows: The distance from the sound source 10 along the reflection path Pr to the reflecting object 30 (reflection point) is hereinafter referred to as the "first distance Da." The evaluation value Q increases as the first distance Da decreases. The evaluation value Q is expressed, for example, by the following formula (2).

Formula (2): Q=f(Lp)+g(Da)

In equation (2), the weight of the first term (f(Lp)) may be set to be greater than the weight of the second term (g(Da)).

The second example further improves the simulation accuracy.

2-2-3. Third Example The materials of the reflective objects 30 present in the target world 1 are not uniform but vary. The reflectance ρ of the reflective object 30 depends on the material of the reflective object 30. In the third example, the evaluation value Q depends on the reflectance ρ of the reflective object 30. Specifically, the higher the reflectance ρ of the reflective object 30, the higher the evaluation value Q. In this case, the evaluation value Q is expressed by the following formula (3) or formula (4).

Formula (3): Q=f(Lp)+h(ρ)
Formula (4): Q=f(Lp)×h(ρ)

The third example further improves the simulation accuracy.

2-2-4. Fourth Example It is also possible to combine the second and third examples described above, which further improves the accuracy of the simulation.

As described above, some of the reflecting objects 30 are excluded from the sound environment simulation based on the evaluation value Q. Furthermore, some of the reflecting objects 30 may be excluded from the sound environment simulation based on other viewpoints.

Figure 7 is a conceptual diagram for explaining an example of objects to be excluded from the sound environment simulation. The fixed range RNG is a finite range that includes the sound source 10. For example, the fixed range RNG is a range up to a fixed distance (e.g., 5 m) from the sound source 10. The contribution of reflecting objects 30 that exist outside the fixed range RNG is considered to be small. Therefore, reflecting objects 30 that exist outside the fixed range RNG may be unconditionally excluded from the sound environment simulation.

More specifically, when extracting reflecting objects 30 capable of forming a reflection path Pr as simulation candidates, the sound environment simulator 100 uses a certain range RNG as a search range. That is, the sound environment simulator 100 extracts reflecting objects 30 capable of forming a reflection path Pr as simulation candidates from among the reflecting objects 30 present within the certain range RNG. In other words, the sound environment simulator 100 excludes reflecting objects 30 present outside the certain range RNG from the simulation candidates in advance. This makes it possible to further reduce the processing load while ensuring the accuracy of the sound environment simulation.

As another example, the contribution of reflecting objects 30 whose size is less than a predetermined value is considered to be small. Therefore, reflecting objects 30 whose size is less than a predetermined value may be unconditionally excluded from the sound environment simulation. More specifically, the sound environment simulator 100 extracts reflecting objects 30 capable of forming a reflection path Pr as simulation candidates from among reflecting objects 30 whose size is equal to or greater than a predetermined value. In other words, the sound environment simulator 100 excludes reflecting objects 30 whose size is less than a predetermined value from simulation candidates in advance. This makes it possible to further reduce the processing load while ensuring the accuracy of the sound environment simulation.

2-4. Effects As described above, according to this embodiment, a representative reflecting object 30-X is selected based on the evaluation value Q. Then, instead of all reflecting objects 30, only the selected representative reflecting object 30-X is used for the sound environment simulation. This makes it possible to reduce the processing load while ensuring the accuracy of the sound environment simulation. As a result, computer resources and costs are also reduced. When the number of representative reflecting objects 30-X is one, the effects are even greater.

8 is a block diagram showing an example of the configuration of a sound environment simulator 100 according to this embodiment. The sound environment simulator 100 includes one or more processors 110 (hereinafter simply referred to as "processors 110"), one or more storage devices 120 (hereinafter simply referred to as "storage devices 120"), and an input/output device 130.

The processor 110 performs various types of information processing. For example, the processor 110 includes a CPU (Central Processing Unit). The storage device 120 stores various types of information required for processing by the processor 110. Examples of the storage device 120 include volatile memory, non-volatile memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc.

The simulation program PROG is a computer program executed by the processor 110. The functions of the sound environment simulator 100 are realized by cooperation between the processor 110, which executes the simulation program PROG, and the storage device 120. The simulation program PROG is stored in the storage device 120. The simulation program PROG may be recorded on a computer-readable recording medium. The simulation program PROG may be provided via a network.

The input/output device 130 is an interface for receiving information from the user and providing information to the user. The input/output device 130 includes an input device and an output device. Examples of input devices include a keyboard, a mouse, a touch panel, etc. Examples of output devices include a display, a touch panel, a speaker, etc. Furthermore, the input/output device 130 may include a communication device that communicates with various devices that exist in the real target world 1.

3-2. World configuration information The world configuration information 200 indicates at least the positions of the components of the target world 1. The components of the target world 1 include at least a sound source 10 and a reflecting object 30. The components of the target world 1 may include objects that can be observation points 20 (e.g., humans, robots). The components of the target world 1 may be moving objects or stationary objects. Examples of moving objects include vehicles, robots, flying objects, etc. Examples of stationary objects include walls, boards, ceilings, floors, ground, structures, etc.

The world configuration information 200 may include information corresponding to the reflectance ρ of the components of the target world 1. In particular, the world configuration information 200 may include information corresponding to the reflectance ρ of the reflective object 30. The information corresponding to the reflectance ρ may be the reflectance ρ itself, or may be the material.

The world configuration information 200 may indicate the size of the components of the target world 1. In particular, the world configuration information 200 may indicate the size of the reflective object 30.

If the sound source 10 has directionality, the world configuration information 200 may indicate the direction (range) in which sound is output from the sound source 10.

The world configuration information 200 may include a semantic model related to the target world 1. The semantic model is a 3D model based on concepts such as BIM (Building Information Modeling) and CIM (Construction Information Modeling). The semantic model includes attribute information of components (especially stationary objects) of the target world 1. Examples of attribute information of components include the type, position, size, material, color, etc. of the component.

The processor 110 acquires the world configuration information 200 via the input/output device 130. For example, the world configuration information 200 is created by a user and input via the input/output device 130. As another example, the processor 110 may communicate with a moving object present in the real target world 1 and acquire the actual position of the moving object in real time. The world configuration information 200 is stored in the storage device 120.

3-3. Processing Example Fig. 9 is a flowchart outlining the sound environment simulation processing according to this embodiment.

In step S100, the processor 110 reads the world configuration information 200 from the storage device 120.

In step S110, the processor 110 extracts, based on the world configuration information 200, reflecting objects 30 capable of forming a reflection path Pr for a combination of a sound source 10 and an observation point 20 as simulation candidates. The observation point 20 may be specified by the user. The number of sound sources 10 may be two or more. If the sound source 10 has directionality, the direction in which sound is output from the sound source 10 is taken into consideration. As described in section 2-3 above, some reflecting objects 30 may be excluded in advance from the simulation candidates.

In step S120, the processor 110 calculates an evaluation value Q for each simulation candidate based on the world configuration information 200. The evaluation value Q is as described in section 2-2 above.

In step S130, the processor 110 selects at least one simulation candidate as the representative reflecting object 30-X based on the evaluation value Q. The processor 110 may select only one simulation candidate with a relatively high evaluation value Q as the representative reflecting object 30-X. The processor 110 may select at least one simulation candidate with the highest evaluation value Q as the representative reflecting object 30-X. The processor 110 may select only one simulation candidate with the highest evaluation value Q as the representative reflecting object 30-X.

In step S140, the processor 110 simulates the sound propagation characteristics of the reflected sound Sr along the representative reflection path Pr-X formed by the representative reflecting object 30-X, without using any reflecting object 30 other than the representative reflecting object 30-X. The processor 110 also simulates the sound propagation characteristics of the direct sound Sd of the direct path Pd.

In step S150, the processor 110 outputs the results of the sound environment simulation via the input/output device 130.

The sound environment simulation makes it possible to know the sound intensity and the direction from which the sound comes at the observation point 20. It also makes it possible to know the delay from the direct sound Sd to the reflected sound Sr at the observation point 20. Such a delay reflects the expansion of the space. Therefore, based on the delay characteristics, it is possible to understand, for example, how a person at the observation point 20 perceives the space. Furthermore, it is possible to know the material-dependent filter effect of the reflecting object 30, that is, how the waveform of the reflected sound Sr changes. The results of the sound environment simulation are reflected in the design and simulation of the target world 1.

1 Target world 10 Sound source 20 Observation point 30 Reflecting object 30-X Representative reflecting object 100 Sound environment simulator 110 Processor 120 Storage device 130 Input/output device 200 World configuration information Pr Reflection path Pr-X Representative reflection path Sr Reflected sound Sr-X Representative reflected sound PROG Simulation program

Claims (9)

A sound environment simulator that simulates a sound environment in a target world,
one or more processors;
one or more storage devices for storing world configuration information indicating at least the positions of sound sources and reflecting objects in the target world;
The reflection path is a path of a reflected sound that is output from the sound source, reflected by any reflecting object, and reaches an observation point,
The one or more processors:
extracting, as simulation candidates, the reflecting objects capable of forming the reflection path for the combination of the sound source and the observation point based on the world configuration information;
calculating an evaluation value for each of the simulation candidates based on the world configuration information, the evaluation value increasing as the length of the reflection path decreases;
selecting at least one simulation candidate as a representative reflecting object based on the evaluation value;
A sound environment simulator that simulates sound propagation characteristics along the reflection path formed by the representative reflecting object without using any reflecting object other than the representative reflecting object. 2. The sound environment simulator according to claim 1,
The one or more processors select only one simulation candidate as the representative reflecting object based on the evaluation value. 2. The sound environment simulator according to claim 1,
The one or more processors select at least one simulation candidate having the highest evaluation value as the representative reflecting object. 4. The sound environment simulator according to claim 3,
The one or more processors select only the one simulation candidate having the highest evaluation value as the representative reflecting object. 5. A sound environment simulator according to claim 1,
a first distance is a distance from the sound source to the reflecting object along the reflected path;
The sound environment simulator, wherein the evaluation value becomes higher as the first distance becomes shorter. 5. A sound environment simulator according to claim 1,
The world configuration information further indicates information corresponding to the reflectance of the reflective object,
The evaluation value increases as the reflectance of the reflecting object increases. 5. A sound environment simulator according to claim 1,
The one or more processors exclude the reflecting objects that exist outside a certain range including the sound source from the simulation candidates. 5. A sound environment simulator according to claim 1,
The world configuration information further indicates a size of the reflective object;
The one or more processors exclude the reflecting objects whose size is less than a predetermined value from the simulation candidates. A sound environment simulation method for simulating a sound environment in a target world by a computer, comprising:
The world configuration information indicates at least the positions of sound sources and reflecting objects in the target world;
The reflection path is a path of a reflected sound that is output from the sound source, reflected by any reflecting object, and reaches an observation point,
The sound environment simulation method includes:
extracting, as simulation candidates, the reflecting objects capable of forming the reflection path for the combination of the sound source and the observation point based on the world configuration information;
calculating an evaluation value for each of the simulation candidates based on the world configuration information, the evaluation value increasing as the length of the reflection path decreases;
selecting at least one of the simulation candidates as a representative reflecting object based on the evaluation value;
and simulating sound propagation characteristics along the reflection path formed by the representative reflecting object without using any reflecting object other than the representative reflecting object.

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