Noise evaluation method

Abstract

To quantitatively evaluate noise generated at a construction site.SOLUTION: A noise evaluation method includes: a data acquisition step of acquiring sound source data; a filtering step of correcting the sound source data with a plurality of filters for attenuating sound pressure to acquire a plurality of pieces of corrected sound source data; an evaluation step of performing, for each of the plurality of pieces of corrected sound source data, organoleptic evaluation for evaluating the degree of noise of a sound included in the corrected sound source data; and an acceptability acquisition step of acquiring, for each of the filters, acceptability representing the ratio of the extent of permission of the sound included in the corrected sound source data. The plurality of filters are set by using a D value that is a sound insulation glass represented by sound insulation performance at a plurality of center frequencies and on the basis of the D values different from each other. Correction with the filters in the filtering step includes calculating, from the D values, the sound insulation performance corresponding the respective frequencies included in the sound source data, and attenuating the sound pressure of the sound source data on the basis of the sound insulation performance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for evaluating noise at a renovation work site or the like. [Background technology]

[0002] Patent Document 1 discloses a technique for evaluating road traffic noise by obtaining a correlation coefficient between the noise impact and noise exposure. [Prior art documents] [Patent documents]

[0003] [Non-Patent Document 1] Kiyoto Izumi, Takashi Yano, Toshio Yamashita "Social Survey on Road Traffic Noise in Hokkaido and Kyushu: Regional Comparative Study of Social Response to Road Traffic Noise 1" Architectural Institute of Japan, Planning Series, Report No. 442, December 1992 Summary of the Invention [Problem to be solved by the invention]

[0004] It has been desirable to reduce noise generated at construction sites and the like. One possible method for reducing noise is, for example, installing sound insulation walls with a certain level of sound insulation performance around the construction site. In order to implement appropriate noise control measures, it is necessary to carry out a noise evaluation to determine the acceptable level of sound volume (sound pressure) and sound characteristics, and to implement noise control measures based on the noise evaluation. To achieve this, a quantitative noise evaluation method is required.

[0005] An object of the present invention is to provide a method for quantitatively evaluating noise generated at a construction site or the like. [Means for solving the problem]

[0006] The present invention is a noise evaluation method including a data acquisition step of acquiring sound source data, a filtering step of acquiring a plurality of corrected sound source data by correcting the sound source data with a plurality of filters that attenuate sound pressure, an evaluation step of performing a sensory evaluation for each of the plurality of corrected sound source data to evaluate the noise level of the sound contained in the corrected sound source data, and an acceptability acquisition step of acquiring, for each filter based on the result of the sensory evaluation, an acceptability indicating the proportion of the sound contained in the corrected sound source data that is tolerable. In the filtering step, the plurality of filters are set so that the D-values, which are sound insulation grades that indicate sound insulation performance at specific frequencies, are different from each other, sound insulation performance corresponding to each frequency included in the sound source data is calculated from the D-value, and the sound pressure of the sound source data is attenuated based on the sound insulation performance. Effect of the Invention

[0007] According to the present invention, noise generated at a construction site or the like can be quantitatively evaluated. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a flow chart showing each step of the noise evaluation method according to the embodiment of the present invention. [Diagram 2] 1 is a table showing noise conditions for a noise evaluation method according to an embodiment of the present invention. [Diagram 3] FIG. 1 is a graph showing D values. [Figure 4] FIG. 1 is a graph illustrating a band pass filter. [Diagram 5] FIG. 4 is a graph showing a process of setting a filter in the noise evaluation method according to the embodiment of the present invention. [Figure 6] FIG. 4 is a graph showing an example of an evaluation result in the noise evaluation method according to the embodiment of the present invention. [Figure 7] FIG. 13 is a graph illustrating a method for acquiring an acceptability in the noise evaluation method according to the embodiment of the present invention, in which the evaluation results are standardized and expressed as a normal distribution. [Figure 8]FIG. 4 is a graph showing the relationship between sound insulation performance and acceptability in the noise evaluation method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a noise evaluation method according to an embodiment of the present invention will be described with reference to the drawings.

[0010] The noise evaluation method of this embodiment is for evaluating noise caused by work sounds and the like generated at a construction or renovation work site (hereinafter simply referred to as "the site") of a building or the like, and is intended to grasp people's tolerance for noise. In the following explanation, an example will be given of evaluating the impact of noise on the surrounding area of ​​the site (for example, an adjacent room or a room downstairs) during indoor renovation work.

[0011] As shown in Figure 1, the noise evaluation method includes a data acquisition step of acquiring sound source data to be evaluated, a filtering step of correcting the sound source data with a plurality of filters that attenuate sound pressure to obtain a plurality of corrected sound source data, an evaluation step of performing a sensory evaluation on each of the plurality of corrected sound source data to evaluate the noise level of the sound contained in the corrected sound source data, and an acceptability acquisition step of acquiring, for each filter, an acceptability that indicates the proportion of the sound contained in the corrected sound source data that is tolerable based on the results of the sensory evaluation.

[0012] [Data acquisition process] In the data acquisition process, sound source data is acquired by recording noise generated under predetermined noise conditions. The predetermined noise conditions include the type of work performed at the site and the site conditions, as shown in Figure 2.

[0013] The work type is set for each work content at the site and for each tool or equipment used. In this embodiment, six levels are set as work types, such as impact driver, tacker, D-board, circular saw, tack driver, and disc grinder.

[0014] The site conditions are set by combining the type of site where the renovation work is being carried out, such as an office, hotel, or hospital, with the sound pressure of background noise (sound other than noise generated during work) that occurs at each site. In this embodiment, three types of site characteristics are set: office, hotel, and hospital, and two levels are set for the sound pressure of background noise for each: 35 dB or 40 dB. In other words, a total of six levels are set as the site type conditions.

[0015] Therefore, in the data acquisition process, a total of 36 levels of sound source data are acquired, consisting of 6 levels of work type and 6 levels of site conditions.

[0016] In addition, when acquiring the sound source data, the sound source data may be acquired by performing actual work at an actual site, or the sound source data may be acquired by performing work in a mock-up that reproduces the site.

[0017] [Filtering process] In the filtering process, first, the filter is set. In this embodiment, the filter is set based on the D value or Dr value (JIS A 1419:2000 Evaluation method for sound insulation performance of buildings and building materials. Hereinafter, referred to as "D value"). The D value is a sound insulation grade expressed by the sound insulation performance at the center frequencies of multiple octave bands, and is expressed by the sound pressure level difference between two spaces separated by a building material at the center frequency of the octave band. In this embodiment, as shown in FIG. 2, the filter is set using seven D values ​​(see FIG. 3) that are close to the specifications of temporary partitions for sound insulation at the site.

[0018] Hereinafter, the filter settings will be specifically described with reference to FIG. 4 and FIG.

[0019] The filters are set by setting a band-pass filter for each of a plurality of center frequencies for which the sound insulation performance is defined in the D value based on the sound insulation performance at the center frequency, and overlapping the band-pass filters. The center frequency of the octave band in the D value is the center frequency of the band-pass filter.

[0020] As shown in FIG. 4, a band-pass filter usually has a passband that passes sound without attenuation (gain is 0), a stopband (attenuation band) that removes sound without passing it, and a transition band between the passband and the stopband. In this embodiment, as shown in FIG. 5, the band-pass filter is set to a shape that has a passband and a transition band, but does not have a stopband. The band-pass filter at each center frequency is set so that the passband fits the value of the sound pressure level difference at the center frequency. In other words, the band-pass filter is set by scaling up the band-pass filter according to the magnitude of the sound pressure level difference of the D value (multiplying the magnitude of the sound pressure level difference as a magnification). The shape of the band-pass filter is determined by the width of the passband and the slope of the transition band. The width of the passband is determined by the cutoff frequency, and the slope of the transition band is determined by the order of the filter. The cutoff frequency and the order of the filter are set arbitrarily based on tests and empirical rules. In this embodiment, the band-pass filter is set to a shape that does not have a stopband, but is not limited to this, and may be set to a shape that includes a stopband.

[0021] The shape of the band-pass filter can be set arbitrarily for each center frequency. As shown in Fig. 5, a band-pass filter (dashed line in the figure) is set for each of multiple center frequencies, and these are superimposed (combined) to set one filter (solid line in the figure). In this way, the sound insulation performance of the center frequency of the D value, which is a discrete value, is extended across the frequency band of the sound source to be evaluated, making it possible to set a filter for the entire frequency band of the sound source to be evaluated. Also, by setting a filter by superimposing band-pass filters, it is possible to interpolate the sound insulation performance between center frequencies as a highly appropriate value.

[0022] Moreover, it is desirable that the band pass filter set for the center frequency is set so as not to affect the pass band of the band pass filter at the other center frequency. Not affecting the pass band means not causing any auditory change. For this purpose, it is desirable that at least the gain of the transition band of a certain band pass filter is set small so as not to exceed the gain of the pass band of an adjacent band pass filter. Furthermore, in consideration of the fact that it is usually said that an auditory sense is affected if the sound pressure level difference is within 10 dB, it is desirable that the difference in gain between the pass band of a certain band pass filter and the transition band of an adjacent band pass filter is 10 dB or more. According to this, the sound insulation performance of the center frequency of the set filter is approximately the same as the sound insulation performance of the D value that is the basis of synthesis, so that the difference between the sound insulation performance of the filter and the sound insulation performance defined as the D value can be reduced.

[0023] When the filters are set in this manner, the sound source data is corrected by each filter to obtain corrected sound source data. The sound source data is corrected by attenuating the sound pressure of the noise included in the sound source data by using the sound insulation performance of the filter. [Evaluation process] In the evaluation process, a sensory evaluation is performed by having a plurality of evaluators evaluate whether or not the uncorrected sound source data and the corrected sound source data obtained by correcting the sound source data (hereinafter, these are collectively referred to as the "sound source to be evaluated") are acceptable as noise.

[0024] Specifically, in a sensory evaluation, evaluators are asked to enter a test room, play each sound source to be evaluated in the test room, and evaluate the degree to which they find the sounds they hear unpleasant. The evaluation is carried out by selecting a five-level evaluation item (category) that indicates a continuum of discomfort (a continuum of psychological responses) to noise. Specifically, the evaluation items are five levels for the discomfort level of the sounds they hear: "0: Very uncomfortable," "1: Somewhat uncomfortable," "2: Neither comfortable nor uncomfortable," "3: Hardly uncomfortable," and "4: Not at all uncomfortable."

[0025] Furthermore, once the noise evaluation is obtained by the evaluation step, an analysis of variance may be performed on the evaluation results with the noise conditions as factors. This makes it possible to confirm whether the noise conditions (type of work, site conditions) in this embodiment are factors that affect the noise evaluation (whether the noise is felt to be unpleasant). In other words, the noise condition items can be set by an analysis of variance on the sensory evaluation. The type of work and site conditions included in the noise conditions in this embodiment have been confirmed by the analysis of variance to be factors that affect the results of the sensory evaluation.

[0026] [Acceptance acquisition process] In the acceptability obtaining step, a statistical process is performed on the evaluation results obtained in the evaluation step to obtain an acceptability indicating a proportion of the sound source that is acceptable as noise for each evaluated sound source.

[0027] The statistical processing for obtaining the acceptability will be described below.

[0028] In this embodiment, the acceptability is obtained using the sequential category method (for example, Yoshihisa Tanaka, Psychological Measurement Methods, 2nd Edition, University of Tokyo Press, 1977) as a statistical process. The sequential category method assumes that the evaluation results from a number of psychologically consecutive categories form a normal distribution, and expresses the boundaries of each category as a distance measure from the average value. This distance measure is expressed as the distance in units of standard deviation on the normal distribution of standardized evaluation results.

[0029] For example, as shown in Fig. 6, in the five-level evaluation result obtained in the evaluation process, the category boundary between tolerable and untolerable noise (hereinafter referred to as "tolerance boundary") is assumed to be the category boundary between "1: Somewhat noticeable" and "2: Cannot say either way." Note that such a tolerance boundary can be set arbitrarily depending on the evaluation item.

[0030] In the graph shown in Fig. 7, the evaluation results are expressed as a normal distribution, with the right side of the graph indicating acceptable and the left side indicating unacceptable. In the graph shown in Fig. 7, the proportion of acceptable noise corresponds to the proportion to the right of the acceptable boundary. This proportion can be expressed as the standardized distance between the acceptable boundary and the average of the evaluation results, which is obtained by the series category method. Therefore, in this embodiment, this standardized distance is obtained as the acceptability in the evaluation results for each sound source to be evaluated.

[0031] Next, the relationship between the standardized distance (acceptability) and the filter D value is obtained for each noise condition, and linear regression is performed on the relationship between the two. The original sound source data that has not been corrected by the filter can be treated as being corrected by a filter with a sound insulation performance of 0, and can be linearly regressed together with the corrected sound source data. Figure 8 shows the sound insulation performance (D value) and acceptability obtained by linear regression when the work type is "impact driver" and the work environment is "office_35dB". The sound insulation performance value is a representative value for each D value, and for example, the value at 500Hz (JIS A 1419) is used. The sound insulation performance value is not limited to the value at 500Hz, and can be a value at any frequency. The linear regression of the relationship between the standardized distance and the D value is performed when the acceptability is between 5% and 95%. As a result, evaluation results such as what level of sound pressure is acceptable and what percentage is acceptable under each noise condition are obtained.

[0032] Next, a construction planning method using the noise evaluation method of this embodiment will be described.

[0033] When the relationship between the standardized distance and the D value is obtained under each noise condition by the noise evaluation method, a temporary partition required for the actual construction work to make the noise in another room adjacent to the construction site a specified tolerance level can be selected based on this relationship. Specifically, the tolerance level required for the construction work is set, and the D value that achieves the set tolerance level is read from the relationship between the noise conditions corresponding to the construction site where the construction work is actually performed. As described above, the tolerance level and the standardized distance can be easily converted. For example, in the example shown in Figure 8, when the type of work is an impact driver, the construction site is an office with a background noise of 35 dB, it can be understood from the evaluation results of the noise evaluation method that a temporary partition with a D value of 40 dB or more should be installed in order to carry out the construction work with a tolerance level of 70%.

[0034] In addition, based on the results of the noise evaluation method, it is possible to determine the maximum sound pressure that can be generated in order to perform work at the set tolerance level with the temporary partitions currently installed at the site (in other words, what types of work are acceptable). This makes it possible to create a construction plan that satisfies the tolerance level, such as performing work that meets the set tolerance level during the day and other work at night or on holidays when there are no people around. This makes it possible to shorten the construction period, reduce construction costs, and reduce work at night or on holidays.

[0035] In addition, this embodiment is useful for so-called construction work while occupants are present, since it can evaluate noise during indoor renovation work. Usually, in construction work while occupants are present at accommodation facilities or commercial facilities, areas are set up where the use of guest rooms and stores around the site is suspended (closed), but by formulating a construction plan using the noise evaluation method of this embodiment, it is possible to suppress the closed areas. Therefore, it is possible to carry out renovation work that does not interfere with the business activities of the client.

[0036] According to the above embodiment, the following advantageous effects are achieved.

[0037] In this embodiment, the filter is set by extending the D value, which indicates the sound insulation grade, to the frequency band of the sound source data. Then, the sound source data is corrected by filters set based on different D values, and an acceptability, which indicates the proportion of noise that can be tolerated as noise, is calculated for each filter. This makes it possible to quantitatively evaluate the level of noise that can be tolerated as noise at construction sites, etc., by setting a level of sound insulation performance (D value).

[0038] In addition, in this embodiment, the relationship between noise conditions (type of work and site environment) and the tolerance level can be acquired. Therefore, based on the relationship between noise conditions in actual construction and the tolerance level, a temporary partition having the sound insulation performance required to satisfy the set tolerance level can be easily selected.

[0039] Next, modified examples of this embodiment will be described. The following modified examples are also within the scope of the present invention. It is also possible to combine the configuration shown in the modified example with the configuration described in the above embodiment, or to combine the configurations described in the different modified examples below.

[0040] In the above embodiment, the acceptability is expressed by a distance measure (standardized distance) of the acceptance boundary by the series category method. However, the method of acquiring the acceptability is not limited to that in the above embodiment. For example, the acceptability may be the ratio of evaluators who answered that the item is acceptable to all evaluators.

[0041] In the above embodiment, a band pass filter is set for each center frequency of the D value, and the filter is set by superposing the band pass filters. In contrast, the filter is not limited to that in the above embodiment as long as it is based on the D value. For example, the filter may be set by linearly or nonlinearly approximating (regressing) the sound insulation performance at each center frequency of the D value. As an example, the filter may be set by linearly interpolating the sound insulation performance of adjacent center frequencies in the D value by connecting them with a straight line.

[0042] In the above embodiment, the sound source to be evaluated includes the sound source data itself acquired in the data acquisition step. In contrast, the sound source to be evaluated may not include the sound source data itself, but may include only the corrected sound source data.

[0043] In the above embodiment, the noise generated by indoor renovation work on the surrounding area is evaluated, but the application is not limited to this. For example, the application may be to evaluate the living sounds generated by people indoors, or to evaluate the sounds generated outdoors, such as the sounds generated by construction work on the exterior of a building.

[0044] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments.

Claims

1. A data acquisition step of acquiring sound source data; a filtering step of correcting the sound source data using a plurality of filters that attenuate sound pressure to obtain a plurality of corrected sound source data; an evaluation step of performing a sensory evaluation for evaluating the noise level of a sound included in each of the plurality of corrected sound source data; and acquiring an acceptability indicating a ratio of an acceptability of the sound included in the corrected sound source data for each of the filters based on a result of the sensory evaluation, The plurality of filters are set based on different D values, which are sound insulation grades represented by sound insulation performance at a plurality of center frequencies, In the correction by the filter in the filtering step, a sound insulation performance corresponding to each frequency included in the sound source data is calculated from the D value, and the sound pressure of the sound source data is attenuated based on the sound insulation performance. Noise assessment methods.

2. The noise evaluation method according to claim 1, In the acceptability obtaining step, the evaluation result of the sensory evaluation is represented as a normal distribution, and the acceptability, which is a ratio of noise that is acceptable as noise, is calculated from the position of the normal distribution of a category boundary of whether the noise is acceptable as noise, which is set in the sensory evaluation. Noise assessment methods.

3. 3. The noise evaluation method according to claim 1 or 2, In the filtering step, a band pass filter is set for each of the plurality of center frequencies based on the sound insulation performance at the center frequency, and the filter is set by overlapping the band pass filters. The band pass filter is set so as not to affect the pass bands of the other band pass filters. Noise assessment methods.

Images