JP6629625B2 - Work environment improvement system - Google Patents

Description

  The present invention relates to a work environment improvement system, and more particularly to a work environment improvement system for improving a work environment related to noise of a worker performing a work by using a masking sound.

  When performing various tasks in a predetermined space, for example, a home or workplace, for example, repetitive simple tasks or intellectual tasks (for example, tasks such as thinking, calculating, and reading / writing with a certain degree of concentration), Noise often affects the efficiency of such intellectual work, and noise measures are being promoted by improving the sound insulation of buildings and changing the structure of home appliances.

  For example, Patent Document 1 discloses an environmental sound generation system that masks noise generated by a multimedia device or the like.

  According to Patent Document 1 described above, for example, when it is assumed that noise is device noise of 100 Hz to 2 kHz, a returning sound of a sea wave is selected as a masking sound for masking a sound in the frequency band. The masking sound is amplified and reproduced from the speaker, whereby the user of the device (the worker of the present invention) hears the masking sound to reduce the psychological and physiological discomfort due to noise.

JP-A-9-319389

  The environmental sound generation system of Patent Document 1 described above has a configuration in which a masking sound is simply added to ambient noise and emitted from a speaker to be heard by an operator. Until now, regarding the technology of masking noise, it has been effective to emit the masking sound and the masking sound to the worker from any direction and position (sound image localization), while giving a comfortable sound. Or, the relevance to the work performed by the worker has not been studied.

  The present invention has been made in view of the above problems, and an object of the present invention is to generate a more accurate masking sound in accordance with noise and to more accurately reduce the influence of noise on a worker who performs work. It is an object of the present invention to provide a work environment improvement system which can be used.

In order to achieve the above object, a work environment improvement system according to claim 1 comprises:
In a work environment improvement system for improving the work environment related to the noise of a worker working in a predetermined space by outputting a masking sound from a masking sound output unit,
Worker position recognizing means for recognizing the position of the worker in the space, noise information obtaining means for obtaining noise information such as the type and position of the noise, and noise information obtained by the noise information obtaining means Masking sound determining means for determining the type of masking sound for weakening the sensitivity of the worker to the noise based on the information, and good sound image localization information for weakening the sensitivity of the worker to the noise set in advance. And a masking sound control unit that performs sound image localization of a masking sound by the masking sound output unit based on the sound image localization information. Based on the location information, the type information of the masking sound from the masking sound determining means, and the good sound image localization information, the sound of the masking sound And performing localization.

  According to this configuration, an appropriate type of masking sound can be transmitted to a worker who is working by appropriate sound image localization. Therefore, for example, it is possible to prevent a worker working at home or the like from sensing external or internal noise as much as possible, and to prevent a reduction in work efficiency due to the noise.

The work environment modification system according to claim 2 is
2. The work environment improvement system according to claim 1, further comprising a work content input unit for inputting the work content of the worker, wherein the sound image localization by the masking sound control unit is performed in advance in accordance with the input work content. It is performed based on the installed good sound image localization information.

  According to this configuration, it is possible to always appropriately set the sound image localization of various appropriate masking sounds depending on the work content.

The working environment improvement system according to claim 3,
3. The work environment improvement system according to claim 2, wherein the sound image localization by the masking sound control unit brings the masking sound close to the ear of the worker when the work content is a repetitive work that does not require individual judgment. The sound image is localized at the position and in the same direction as the noise.

  This configuration shows a specific application example of the second aspect, and is set to a sound image localization that is recognized in advance through experiments or the like, that is, a sound image localization that is favorable in a simple repetitive operation.

The working environment improvement system according to claim 4,
3. The work environment improvement system according to claim 2, wherein the sound image localization by the masking sound control unit determines the direction of the masking sound in front of the worker when the work content is an intelligent work requiring individual judgment. Is characterized in that a sound image is localized.

  This configuration shows a specific application example of the second aspect, and is set to a sound image localization recognized in advance by an experiment or the like, that is, a sound image localization that is good in the case of an intellectual task requiring individual judgment. Things.

The working environment improvement system according to claim 5,
5. The work environment improvement system according to claim 1, wherein when the type of the noise acquired by the noise information acquisition unit is a talk program on a television, the masking sound determination unit is configured to output a 177 to 5656 Hz. The band-limited pink noise is determined as a masking sound.

  This configuration shows a specific application example of claims 1 to 4 described above. In the case of a type of a good masking sound for noise or the like recognized in advance through experiments or the like, that is, in the case of a television talk program, A good masking sound is set in an appropriate manner. Thereby, the function of the invention described in claims 1 to 4 can be further enhanced.

The working environment improvement system according to claim 6,
The work environment improvement system according to any one of claims 2 to 4 , further comprising a cerebral blood flow measurement unit configured to measure a cerebral blood flow of the worker in a predetermined brain region corresponding to the work content. The sound image localization by the masking sound control unit is performed based on the good sound image localization information set in advance for the measured cerebral blood flow information.

  According to experiments, the sensitivity of workers to noise varies depending on the state of cerebral blood flow. The present invention sets a better sound image localization based on the measurement result of the cerebral blood flow. Thereby, the effects of the above-described claims 2 to 5 can be obtained accurately.

The working environment improvement system according to claim 7,
7. The working environment improvement system according to claim 6, wherein the sound image localization by the masking sound control unit has information on the sensitivity of the worker to noise corresponding to cerebral blood flow information obtained in advance, and the measured sound image localization is performed. When the cerebral blood flow information indicates that the worker has high sensitivity to noise, the azimuth of the masking sound is localized at the same position as the noise.

  This configuration shows a specific application example of the above-mentioned claim 6, and recognizes the level of sensitivity of the worker to noise by measuring the cerebral blood flow, and when the sensitivity is high, a good sound image localization for this. By setting (to the same position as the noise), more appropriate masking sound is generated.

  According to the working environment improvement system of the present invention, the masking sound according to the type of noise is determined, and the masking sound is localized in the sound image so that the influence of the noise is reduced more accurately. It is possible to accurately prevent a decrease in work efficiency due to the noise of the worker.

It is a block diagram of a work environment improvement system of the present invention. It is a flowchart which shows the actual procedure which improves the work environment of the work environment improvement system of this invention. A working environment improvement system according to an embodiment of the present invention is applied to a living space. It is explanatory drawing of the evaluation result regarding noise. FIG. 9 is an explanatory diagram of an evaluation result regarding a masking sound. This section shows the positions where noise and masking sound are generated. 4 shows a time protocol for reproducing noise and a masking sound. The following shows the results of performing the calculation task for each type of worker. The following shows the results of performing the calculation task for each type of worker. However, this is the case with a masking sound. The results of cerebral blood flow measurement are shown. However, Calc. It is about a section, and shows workers by type. The result of the calculation task performed by the worker will be described.

  Hereinafter, an embodiment of a work environment improvement system of the present invention will be described in detail with reference to the drawings.

  This embodiment shows an example in which the system of the present invention is installed in a living space, for example, assuming that a target person performs some work in a living space.

  FIG. 1 is a block diagram of a work environment improvement system according to the present invention. A work environment improvement system 10 has a central processing control unit 12 for controlling the entire system. Each means is connected.

  That is, a worker position recognizing unit 15 for recognizing a position where the worker works in the living space, a noise information obtaining unit 16 for obtaining information such as a type, a direction, and a position of noise inside and outside the living space; When noise information is recognized in advance, a noise information input means 17 for inputting the noise information is connected. In addition, a work purpose input means 42 for directly inputting a work purpose and a display means 44 for displaying various information data and the like as necessary are connected. Finally, the central processing control unit 12 is connected to the masking sound output means 40, and outputs a masking sound whose sound image has been properly localized.

  First, the worker position recognizing means 15 is a means for recognizing the location of a worker who works in the living space. For example, the worker's situation is imaged with a camera or the like, and the location of the worker is determined based on the acquired image. Recognition can be performed.

  The noise information acquisition unit 16 is a unit that acquires the position (including azimuth), sound quality (sound pressure, frequency characteristics), temporal fluctuation, and the like of noise generated inside and outside the living space, and includes a microphone, a frequency analyzer, and the like. Are used. The noise information input means 17 is configured to be able to directly input such information from the noise information input means 17 when the position, sound quality, and the like of the noise are known in advance.

  The masking sounds are various sounds for masking noise. For example, various masking sounds such as pink noise, noise attenuated at -6 dB / octave, and noise in which the band is limited to 177 to 5656 Hz are masked sounds. It is stored in a storage unit 26 (described later). It is a matter of course that means for generating a masking sound signal may be provided so as to generate an accurate masking sound for noise.

  Next, the central processing control unit 12 will be described. The central processing control unit 12 includes an information receiving / storing unit 19 for inputting data obtained by the various units described above, an information processing unit 27 for processing the input various information, and a masking sound determining unit for determining a masking sound. 34, a masking sound control unit 35 for performing sound image localization control of the masking sound, and a good sound image storing good sound image localization information for various types of noise based on a sound image localization theory obtained in advance by experiments in order to perform good sound image localization. A localization information storage unit 36 is provided.

  The information receiving / storing means 19 includes an operator position information receiving unit 21, a noise type information receiving unit 22, and a noise position information receiving unit 24 for receiving the data acquired by the various units (15, 16, 17) described above. And a masking sound storage unit 26 described above. A characteristic feature is that an operator cerebral blood flow information storage unit 20, which is a storage unit for information on cerebral blood flow, is provided.

  The worker cerebral blood flow information storage unit 20 is a unit that stores information about sensitivity to noise derived from the characteristics of the cerebral blood flow of the worker that is acquired in advance. In other words, the process is based on the theory that by acquiring a change in cerebral blood flow that occurs when a worker performs a task, it is possible to finally determine the sensitivity of the worker to noise.

  For example, when an intellectual task such as calculation is performed in a noise-free state, a change in blood flow in the frontal lobe occurs due to a phenomenon described later, and the tendency differs depending on the operator. Then, the difference in the tendency appears as the difference in the tendency of the decrease in the work efficiency when noise is present. Therefore, blood flow information of a target worker is acquired in advance, and information such as sensitivity to noise during the work is acquired, and this information is used for sound image localization of a masking sound.

  Next, the worker position information receiving unit 21 receives information on the position of the worker recognized by the worker position recognition unit 15. The noise type information receiving unit 22 receives the frequency characteristics, sound pressure, time characteristics, and the like of the noise acquired by the noise information acquiring unit 16. The noise position information receiving unit 24 receives information on the position of the noise acquired by the noise information acquiring unit 16. In the present embodiment, for example, the position of the noise is determined based on the position information of the worker in the living space obtained by the worker position recognizing unit 15, and the noise is generated by a three-dimensional map. Identify the location. Accordingly, the direction of the noise is also recognized thereby. As described above, various appropriate masking sounds corresponding to noise are stored in the masking sound storage unit 26, and can be selectively used. It is also possible to provide a masking sound signal generating means here.

  Next, the information processing means 27 will be described. This is for processing the data received and stored by the information receiving / storing means 19, and includes the cerebral blood flow information processing unit 28, the worker position information processing unit 29, the noise type information processing unit 30, the noise position An information processing unit 32 is provided.

  The cerebral blood flow information processing unit 28 transmits information on the level of sensitivity of the worker to noise estimated based on the cerebral blood flow information of the worker stored in advance as noise sensitivity information for use in sound image localization. Is what you do.

  In the worker position information processing section 29, the position of the worker in the living space is specified and converted into data. The noise type information processing unit 30 determines the type of noise from the frequency characteristics, time characteristics, sound pressure, and the like of the input noise. For example, it is possible to determine from the above information that noise is a type of television talk program. Further, the noise position information processing unit 32 specifies a noise generation position on a three-dimensional map centered on the worker from the received noise position information.

  The masking sound determining means 34 is adapted to reduce the sensitivity of the worker to a good masking sound, that is, a good masking sound obtained in advance through experiments or the like, in accordance with the type of noise determined by the noise type information processing unit 30. The appropriate masking sound is determined. For example, when the type of noise is a television talk program, the masking sound is pink noise whose band is limited to 177 to 5656 Hz.

  The good sound image localization information storage unit 36 stores good sound image localization information set in advance by experiments or the like in order to reduce the sensitivity of the worker to noise.

  In the masking sound control unit 35, the location information of the worker from the worker position information processing unit 29, the type information of the masking sound from the masking sound determination unit 34, and the good sound image localization information from the good sound image localization information storage unit 36 Based on the sound image localization information, a sound image localization process of a good masking sound is performed.

  The masking sound output unit 40 is a unit that outputs a masking sound based on the localization determined by the masking sound control unit 35. For example, a speaker or headphones is used. For example, the speakers are installed at a plurality of locations, and the outputs from the speakers are controlled by the masking sound controller 35, whereby the actual sound image localization is performed. Further, even when a speaker or the like cannot be installed at an optimum position, it is possible to reproduce a sense of localization by using a stereophonic technique.

  FIG. 2 is a flowchart showing an actual procedure for improving the work environment by the work environment improvement system of the present invention. First, in FIG. 2A, the location of the worker in the living space is recognized (step S1). As described above, the worker location information is input to the worker location information receiving unit 21 by the worker location recognition unit 15 as the video information acquisition unit, as described above. It is recognized by being analyzed by the unit 29.

  Next, the type and position of the noise are acquired (step S2). As for the type and position of the noise, noise information is acquired by the noise information acquiring unit 16 such as the above-described microphone, and the information is input to the noise type information receiving unit 22 and the noise position information receiving unit 24, and the noise type information processing unit 30 Is determined by the analysis performed by the noise position information processing unit 32. As described above, when the information about the noise is obtained in advance, the noise information such as the position, the sound quality (sound pressure, frequency characteristics), and the time change of the noise is input from the noise information input unit 42 to the noise type information receiving unit 22. Input to the noise position information receiving unit 24.

  Next, a masking sound corresponding to the type of noise is determined (step S3). When the noise type is determined by the noise type information processing unit 30, a good masking sound for weakening the sensitivity of the worker to noise is selected from various masking sounds stored in the masking sound storage unit 26 in advance. Selected and determined.

  Next, as the basic processing of the present invention, next, in step S4, the sound image localization by the masking sound control unit 35 is performed based on the worker position information obtained above and the information of the selected and determined masking sound. Processing (selection and determination of the content of sound image localization) is performed. That is, the sound image localization is further determined from the above information by referring to the good sound image localization information stored in the good sound image localization information storage unit 36 which is set in advance to reduce the sensitivity of the worker to noise. Is done.

  Then, as the final step S5, the masking sound control unit 35 controls the output of the masking sound output means 40, so that the output of the masking sound is performed under appropriate sound image localization.

  Next, an embodiment in which another element is used for sound image localization (step S4) will be described with reference to FIG. For example, the elements used are A: work content, B: cerebral blood flow data, and the like. For example, when the specific content is input by the work content input unit 42, or the sensitivity of the worker to the noise estimated based on the cerebral blood flow described above is recognized. It can be used when there is.

  Hereinafter, a procedure for selecting and using these elements will be described. The selection of these elements may be selected by the system user, or a priority may be assigned to one of the elements. If there is only one of the information, the information is given. It is conceivable to select with.

  First, when the "work content" of A is input by the work content input means 42, the central processing unit 12 recognizes this (step S6), and the work content information is stored in the good sound image localization information storage unit 36. Is stored. The masking sound control unit 35 selects and determines a good sound image localization corresponding to the work content information according to the work content information (step S7).

  If the information on the cerebral blood flow data of B has been acquired in advance (step S8), the sound image localization based on the information on the cerebral blood flow of this worker is possible, and the above-described priority and the selection of the user make the sound image localization possible. The level of sensitivity of the worker to noise is determined from the information on the cerebral blood flow, and a good sound image localization is selected and determined by the masking sound control unit 35 (step S9). Here, the relationship between the cerebral blood flow data and the level of sensitivity to noise was determined as follows.

  First, the cerebral blood flow during the execution of a computational task, which is an intelligent task, is measured. This calculation task is performed when there is no noise and when there is noise. The calculation task for the worker is to randomly present the addition or multiplication of 1 to 10 on a monitor screen set at 0.9 m in front of the worker, and the worker solves many problems as quickly as possible using the numeric keypad. That is. Correction is not possible if the answer is wrong. During the task, the cerebral blood flow of the worker is measured by the cerebral blood flow measuring means.

  The worker can compare the case with no noise with the case with noise and classify it into three types according to the number of answers and the number of correct answers. A worker who increases both the number of answers and the number of correct answers is A type, a worker whose number of answers increases and the number of correct answers decreases is B type, and a worker whose both the number of answers and the number of correct answers decrease is C type. It can be said that this type C worker has a high sensitivity to noise.

  The cerebral blood flow data, particularly the increase in oxyhemoglobin in the frontal lobe, when performing the computational task performed in the absence of noise, can be significantly distinguished among the above three types of workers. Was.

  Thus, from the data of the cerebral blood flow of the worker, the level of the oxyhemoglobin in the frontal lobe can be directly estimated from the cerebral blood flow data.

  Using the good sound image localization information, the worker's location information recognized by the worker position recognition means 15, and the masking sound type information determined by the masking sound determination means 34, a masking sound control unit is used. The sound image localization processing by 35 is performed, and the masking sound localized in the sound image is output by the masking sound output means 40.

As a result, the masking sound is determined according to the type of the noise, and the masking sound is localized so that the influence of the noise is more accurately reduced. Can be accurately prevented.

  Next, an embodiment of the work environment improvement system of the present invention will be described. FIG. 3 shows an example in which the work environment improvement system of the present invention is incorporated in a living space. It is assumed that the worker W sits on the sofa 52 in the living space 50 and is working while watching the monitor screen 54 of the personal computer placed in front. A television (TV) 56 is installed on the right side of the worker W, and a window 58 is on the left side. An acoustic device 60 such as a kitchen or a boombox is installed diagonally behind the worker W. Further, a cleaning robot 62 for cleaning the room is installed on the floor. In such an environment, the worker W receives a noise N1 such as a human conversation or a walking sound from the window 58, a noise N2 such as a program sound from the television 56, and a cooking sound or a telephone from a diagonal rear. The noise N3 such as the sound of the motor and the noise N4 such as the rotation sound of the motor are heard from the cleaning robot 62. Arrows 100 to 103 indicate paths through which the noise is transmitted to the worker W.

  The worker W concentrates on the work while looking at the front monitor screen 54. However, when the above-mentioned noises N1 to N4 are generated, the work environment improvement system of the present invention (only the speaker which is the masking sound output means is shown. First, the position of the worker W in the living space 50 is recognized. Next, the types and positions of the noises N1 to N4 are specified, and masking sounds that effectively mask the noises N1 to N4 are determined. Then, for these masking sounds, good sound image localization is determined from the sound image localization information storage unit, and the respective masking sounds are emitted from the speakers SP1 to SP7 as illustrated. The path through which the masking sound is transmitted to the worker W is indicated by arrows 200 to 205.

  Here, the worker W can input the work content from a work content input unit (not shown), and can perform good sound image localization in consideration of the work content. Further, good sound image localization can be achieved in consideration of the sensitivity of the worker W to noise. The speakers SP1 to SP7 are installed on windows, televisions, sofas, etc., but if the speakers cannot be installed, it is as if the speakers are installed there by reproducing the sense of localization by using stereophonic technology and masking from there. It is possible to make the user feel that sound is being generated. With this configuration, even in an environment where the noises N1 to N4 are audible, the worker W can continue the work without being disturbed by the noises N1 to N4 while improving the work efficiency and accuracy.

  In the following, the experimental results relating to the type of noise, the determination of the masking sound for the noise, the effect of sound image localization of the masking sound, the estimation of sensitivity to noise, and the sound image localization according to the work purpose will be described in detail.

Type of noise Identify unpleasant noises that cannot be concentrated in the living noises generated in the living space. The following eight types of noise were assumed in the experiment. That is, Pink Noise, News, Variety show (variety show and talk show), Music live (music live), Drama1domestic (drama 1), Drama2 domestic (drama 2) Animation (animation), Sports baseball (Sports, baseball). Other than the pink noise, it is a television program, and is a sound played from the television. These noises were reproduced at 55 dBA at the center position of the worker's head in a soundproof room with 25 dBA of background noise, and a calculation task assuming a concentrated state was performed. For the calculation task, a calculation sheet in which addition or multiplication of 1 to 10 were arranged at random was prepared, and many problems were solved as quickly as possible in 30 seconds. The impression during the experiment was subjectively evaluated using three indices. The discomfort level of the sound environment (Discomfort level, 1: no effect to 5: discomfort) and the concentration inhibition degree for the calculation task (Deconcentration level, 1: no effect to 5: inability to concentrate) were each absolutely evaluated in five steps. In addition, whether attention was paid to noise or computational tasks during the experiment was evaluated as a percentage as Attention allocation. The experiment was performed by 12 workers in the 20s. The experimental results are shown in FIG.

  In FIG. 4, the evaluation values of the discomfort level for the sound environment (Discomfort level) and the concentration inhibition degree (Deconcentration level) for the calculation task are shown in a bar graph. allocation) is indicated by a polygonal line. These are the average value and the standard deviation between workers.

  Television talk programs are composed of content that is of interest to many people, and include many characteristic sounds such as sound effects and laughter of the audience. be able to.

Determination of Masking Sound Using the above talk program as noise, an optimal masking sound for masking this noise is selected. Four types of masking sounds were selected: pink noise, noise attenuating at -6 dB / octave, and noise in which each noise was band-limited (BPF) to 177 to 5656 Hz. The volume of the masking sound was three types of 50, 55, and 60 dBA at the center position of the head. There were 10 workers in the 20s, and the 12 masking sounds described above were mixed with a talk program for 30 seconds at 55 dBA, and played in the soundproof room in a random order to the workers. The unpleasantness of the sound environment during the experiment and the impression of the degree of concentration inhibition on the calculation task were each absolutely evaluated on a seven-point scale.

  FIG. 5 shows the evaluation results. The evaluation values of the degree of discomfort (Discomfort level) and the degree of concentration inhibition (Deconcentration level) are summed, and the average value and the standard deviation between workers are shown. As a result, the total evaluation value of the band-limited (BPF) 50 dBA pink noise is the minimum, and it can be evaluated as a masking sound that is the least uncomfortable and can be concentrated. Since this masking sound mainly covers the voice band, it can be said that the masking sound having a frequency characteristic close to noise is suitable not only for concealing the noise but also for maintaining the concentration. The larger the volume of the masking sound is, the more the noise can be hidden, but if the volume is the same as the noise, the masking sound cannot be hidden. Also, if the volume is higher than the noise, the masking sound itself will be uncomfortable. For this reason, the masking sound that can be concentrated without being uncomfortable is a sound volume several dB lower than the noise.

Effect of Sound Image Localization of Masking Sound FIG. 6 shows sound image localization of four types of masking sounds M1 to M4 with respect to noise (Noise) generated obliquely to the front of the worker W. A variety show (talk program) on a television was used as the noise, and the sound pressure was 55 dBA. The noise is 45 degrees diagonally to the right of the worker W, at a distance of 1.7 m. The masking sound was pink noise whose band was limited to 177 to 5656 Hz, and the sound pressure was 50 dBA. The reason why the sound pressure of the masking sound was lowered by 5 dB from the sound pressure of the variety show on the television is based on the result of the above experimental study. By setting the sound pressure in this manner, the worker can concentrate on the work without feeling uncomfortable.

  The masking sound is localized in the sound images at M1 to M4, but M1 is placed at the same position as the noise source and is expected to directly hide the noise. M2 is placed 1.7 m in front of the worker, and is expected to function as a background sound when heard equally to the left and right ears. M3 is expected to distract from the noise by drawing attention to the masking sound near the ear. In M1 to M3, the sound pressure of the masking sound is set so that the average of the left and right levels at the ear position is 50 dBA. M4 is arranged closer to the front than M3, and the arrangement is such that the difference between the left and right noise levels at the ear position of the noise and the masking sound is the same. This is because, even in the same localization direction, the noise level difference between the left and right ears increases as the distance between the sound source and the worker decreases. M4 is expected to mask at the same ratio as noise in the left and right ears.

  The noise and the masking sound were reproduced according to the time protocol shown in FIG. Rest is a preparation section, and Calc.task is a section for performing a calculation task without noise or masking sound. Calc.task + Noise is a section for performing a calculation task while listening to noise, and Calc.task + Nosie + Masker is a section for performing a calculation task while listening to noise and masking sound. The masker, that is, the localization of the masking sound is randomly selected three times from M1 to M4. These sections are performed four times in total. The calculation task for the worker is to randomly present the addition or multiplication of 1 to 10 on a monitor screen set at 0.9 m in front of the worker, and the worker solves many problems as quickly as possible using the numeric keypad. Was instructed. Correction is not possible if the answer is wrong. During the task, the cerebral blood flow of the worker is measured by the cerebral blood flow measuring means.

  FIG. 8 shows the number of answers (Answer) and the number of correct answers (Correct answer) in the Calc. Section for each type of worker. The total number of workers is 18 people in the 20s and indicates the number of answers and the number of correct answers per 25 seconds in one section. Data was totaled for each section shown in FIG. The Calc. Section averaged four runs. The Calc. + Noise section (hereinafter referred to as Noise) averaged 12 times, and the Calc. + Noise + Masker 1-4 sections (hereinafter referred to as M1 to M4) averaged three times.

  The worker compared the Calc. Section with the Noise section and was able to classify it into three types. A worker who increases both the number of answers and the number of correct answers is A type, a worker whose number of answers increases and the number of correct answers decreases is B type, and a worker whose both the number of answers and the number of correct answers decrease is C type. In FIG. 8, the number of answers and the number of correct answers in each section are divided by the number of answers under the Calc. Condition, and this is defined as the answer number ratio and the correct answer number ratio. In FIG. 8, the average value and the standard deviation between workers are shown for each type, and a value obtained by dividing the number of correct answers by the number of answers is indicated by a polygonal line as an accuracy rate (Accuracy rate). It can be said that a type C worker in which both the number of answers and the number of correct answers decrease due to noise has a high sensitivity to noise.

  FIG. 9 shows the result of listening to the masking sound in each type. Nine A-type subjects had a high number of correct answers (Accuracy rate) under the M2 condition, and the number of correct answers significantly increased between Noise and M2. The A-type worker has improved the work efficiency due to the noise, but can further improve the accuracy by the masking sound. It can be inferred that the masking sound in front of M2 functions as a background sound that hides the details of noise while maintaining a rhythmic feeling, and that the calculation accuracy has improved.

  The number of correct answers, the number of correct answers, and the correct answer rate are all the maximum under the M3 condition, and the variation of each of the five B type persons is small. For a B-type person, the masking sound at a position close to the ear of M3 functions as a sound distracting from noise, and as a result, it can be inferred that the number of answers and the number of correct answers have increased from the Calc.

  The number of answers, the number of correct answers, and the percentage of correct answers were all the maximum under the M1 condition, and the number of correct answers significantly increased in Noise-M1 in the four C-types. Since the person of type C is distracted by the noise, it can be inferred that by directly masking at the same position as the noise of M1, the same level of concentration as in the Calc.

Estimation of Sensitivity to Noise FIG. 10 shows a part of the measurement results of cerebral blood flow. For oxygenated hemoglobin (Oxy-Hb), long-period fluctuations were removed, and the increase in Oxy-Hb in the Rest → Calc. Section was evaluated. For this purpose, the difference between the average value of Oxy-Hb in the target section and the average value of Oxy-Hb for the last 5 seconds in the section immediately before the target section was taken as the cerebral blood flow increment value (ΔOxy-Hb). Among 18 workers, the number of effective trials and the average increase are shown in NIRS measurement.

  For the A-type workers whose both the number of answers and the number of correct answers have increased due to noise, the increase in Oxy-Hb at the central front pole shown by the black frame is remarkable. This region corresponds to the 9th to 10th areas of the Broadman brain map, and is said to be responsible for higher-level information processing. It can be inferred that the A-type worker worked carefully so as not to make a calculation error by utilizing a higher-order part because of the low calculation speed.

  The B-type worker whose number of answers has increased and the number of correct answers has decreased has a remarkable increase in Oxy-Hb in the left and right language areas indicated by black frames. This part corresponds to the 44th to 47th areas of the brain map of Broadman, and is considered to be involved not only in the speech function but also in connection with complicated hand movements and sensory stimuli and movements. It can be inferred that the worker of type B has a higher calculation speed than the worker of type A, and can perform calculations without using higher-order parts, and has thus worked out the calculations to some extent.

  In the case of the C-type worker in which both the number of answers and the number of correct answers have decreased, the channel in which Oxy-Hb increases and the channel in which Oxy-Hb decreases are finely divided, and only a part of the brain is activated. Since the operator of the C type has the highest calculation speed, it can be inferred that a brain circuit suitable for the calculation task is configured and routine work is performed.

  As described above, in the Rest → Calc. Section, since a characteristic brain activity pattern is observed for each type, it is possible to estimate the sensitivity to noise by measuring the brain activity in the Calc. Section. If the masking sound is switched to an appropriate localization in accordance with the estimated sensitivity and reproduced, the discomfort level of the noise is reduced, leading to an improvement in work efficiency and accuracy. In other words, it can be seen that the sensitivity to noise can be estimated from the pattern of brain activity at the time of calculation with no sound, and a masking localization suitable for work requiring concentration can be proposed.

Sound image localization of masking sound according to work purpose FIG. 11 shows experimental data of 18 workers in the 20-year-old range shown in FIGS. The average value and standard deviation between workers for all workers are shown. As in FIG. 8, the number of answers in the Calc. Section is normalized as one. The polygonal line indicates the accuracy rate (Accuracy rate) as in FIG.

  First, when noise is added from a silent state, the number of answers (Answer) significantly increases and the number of correct answers (Correct answer) also tends to increase when Calc. And Noise in FIG. 11 are compared. It can be understood that even if the noise is unpleasant, the working efficiency is not necessarily affected.

  Next, as for the result when the masking sound is added to the noise, the number of answers is the highest in the M3 condition, and the number of correct answers and the number of correct answers are the highest in the M2 condition. In addition, a significant increase was confirmed in the number of answers between Noise-M3, the number of correct answers between Noise-M2 and M3, and the correct answer rate between Noise-M2 by the t-test based on the Noise section.

  In the masking localization of M3, the number of answers and the number of correct answers significantly increase with respect to the Noise section, and there is no significant difference in the correct answer rate. Therefore, it can be said that the accuracy is not changed but the work efficiency is improved. In addition, in the masking localization of M2, the number of correct answers and the correct answer rate increase, and there is no significant difference in the number of answers. Therefore, it can be said that work efficiency does not change but accuracy is improved.

  Neither M3 (position near the ear) nor M2 (front) is a localization that directly hides the noise, but M3 distracts from the noise by drawing attention to the masking sound near the ear, and M2 is the background sound. It was thought that the effect of noise could be reduced and the work efficiency and accuracy could be improved because it functioned as a mask and masked the fine parts of noise.

  From the above, the masking localization of M3 (in the direction close to the ear and in the same direction as the noise) that improves work efficiency is optimal for simple tasks that repeat the same, and for tasks that emphasize accuracy, The masking localization of M2 (front) that improves the accuracy is optimal.

  According to the working environment improvement system of the present embodiment, a masking sound is determined according to the type of noise, and the determined masking sound is output based on good sound image localization information. It is also possible to perform sound image localization satisfactorily according to the work purpose and the sensitivity of the worker to noise. Therefore, the work environment is optimized, and the worker can continue the work while improving the work efficiency and accuracy without reducing the work efficiency even if there is noise.

  It should be noted that the present invention is not limited to the range described in the above embodiment, and various changes can be made within the scope of the invention. For example, although the cerebral blood flow measuring means measures using NIRS, it is not limited to this, and for example, fMRI (functional magnetic resonance imaging) or the like may be used. Although the sound output means has been described using an example using a speaker, headphones may be used. If such a sound output means cannot be installed, a sense of localization may be reproduced by using a stereophonic technique.

DESCRIPTION OF SYMBOLS 10 Working environment improvement system 12 Central processing control part 15 Worker position recognition means 16 Noise information acquisition means 17 Noise information input means 19 Information reception and storage means 20 Worker's cerebral blood flow information storage part 21 Worker position information reception part 22 Noise type information receiving unit 24 Noise position information receiving unit 26 Masking sound storage unit 27 Information processing means 28 Cerebral blood flow information processing unit 29 Worker position information processing unit 30 Noise type information processing unit 32 Noise position information processing unit 34 Masking sound determination Means 35 Masking sound control unit (sound image localization)
36 Good sound image localization information section 40 Masking sound output means 42 Work content input means 44 Display means 50 Living space N1 to N4 Noise SP1 to SP7 Masking sound output means W Worker

Claims (7)

In a work environment improvement system for improving the work environment related to the noise of a worker working in a predetermined space by outputting a masking sound from a masking sound output unit,
Worker position recognition means for recognizing a position of the worker in the space,
Noise information acquisition means for acquiring noise information such as the type and position of the noise,
Masking sound determining means for determining the type of masking sound for weakening the sensitivity of the worker to the noise based on the noise information obtained by the noise information obtaining means;
A masking sound control unit having good sound image localization information to weaken the sensitivity of the worker to the noise set in advance, and performing sound image localization of a masking sound by the masking sound output unit based on the sound image localization information, Has,
The masking sound control unit includes:
Worker location information from the worker location recognition means,
Masking sound type information from the masking sound determining means;
A sound image localization of a masking sound based on the good sound image localization information; Having a work content input means for inputting the work content of the worker,
The sound image localization by the masking sound control unit,
2. The work environment improvement system according to claim 1, wherein the operation is performed based on the good sound image localization information set in advance corresponding to the input work content. 3. The sound image localization by the masking sound control unit,
The method according to claim 2, wherein when the work content is a repetitive work that does not require individual judgment, the masking sound is localized at a position close to the ear of the worker and in the same direction as the noise. Work environment improvement system. The sound image localization by the masking sound control unit,
The work environment improvement system according to claim 2, wherein when the work content is an intelligent work requiring individual judgment, the direction of the masking sound is localized in a sound image in front of the worker.   When the type of the noise acquired by the noise information acquiring unit is a talk program of a television, the masking sound determining unit determines pink noise band-limited to 177 to 5656 Hz as the masking sound. The work environment improvement system according to any one of claims 1 to 4. Having a cerebral blood flow measurement means for measuring the cerebral blood flow of the worker in a predetermined brain region corresponding to the work content,
The sound image localization by the masking sound control unit,
The working environment improvement system according to any one of claims 2 to 4 , wherein the system is performed based on the good sound image localization information set in advance for the measured cerebral blood flow information. The sound image localization by the masking sound control unit,
Having information on the sensitivity of the worker to noise corresponding to cerebral blood flow information obtained in advance,
The azimuth of the masking sound is localized at the same position as the noise when the measured cerebral blood flow information indicates that the worker has high sensitivity to noise. Work environment improvement system.

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