JP6197662B2 - Reverberation time analyzer - Google Patents

Description

  The present invention relates to a technique for measuring reverberation time.

  Techniques for measuring the reverberation time of an acoustic space such as a conference room or a hall (hereinafter referred to as “measurement space”) have been proposed. For example, Patent Document 1 discloses a technique for displaying reverberation time (reverberation time-frequency characteristics) measured for each of a plurality of frequency bands on a display device.

Japanese Unexamined Patent Publication No. 7-038987

  By the way, in the scene where the reverberation time is actually measured, an error may occur in the measurement result of the reverberation time due to the influence of the background noise existing in the measurement space. However, determining whether the reverberation time measurement result is an appropriate value that reflects the actual characteristics of the space under measurement or an unreliable value that includes errors due to background noise is an acoustic measurement. It is difficult for users who do not have enough specialized knowledge. In view of the above circumstances, an object of the present invention is to enable a user to easily grasp the suitability of a reverberation time measurement result.

  In order to solve the above problems, a reverberation time analysis apparatus according to a first aspect of the present invention includes a noise analysis unit that measures an S / N ratio in a measured space for each of a plurality of frequency bands, and a plurality of frequency bands. Reverberation analysis means for measuring the reverberation time in the measured space for each, and means for displaying the reverberation time on a display device for each frequency band, and the reverberation of the frequency band whose SN ratio is below the threshold value among the plurality of frequency bands Display control means for excluding time from display targets. In the above configuration, the reverberation time of the frequency band in which the SN ratio is lower than the threshold among the plurality of frequency bands is excluded from the display target. Therefore, there is an advantage that the user can easily grasp whether or not the reverberation time measurement result is appropriate (the reverberation time of the display target is sufficiently reliable).

  The reverberation time analysis apparatus according to the second aspect of the present invention includes a noise analysis unit that measures an S / N ratio in a measured space for each of a plurality of frequency bands, and each of the plurality of frequency bands. Reverberation analysis means for calculating the reverberation time of the space under measurement according to the length of time that the sound intensity in the frequency band is attenuated by a reference amount variably set according to the SN ratio, and the reverberation time is displayed for each frequency band Display means for displaying on the apparatus, the display control means changing the display mode of each reverberation time measured under different reference amounts. In the above configuration, the reference amount applied to the calculation of the reverberation time is variably set according to the SN ratio, and the reverberation times corresponding to different reference amounts are displayed on the display device in different modes. Therefore, there is an advantage that the user can easily grasp whether the measurement result of the reverberation time is appropriate (reliability of each reverberation time).

  In a preferred aspect of the present invention, the reverberation analysis means remeasures the reverberation time of the frequency band instructed by the user among the plurality of frequency bands. In the above aspect, since the reverberation time of the frequency band instructed by the user is remeasured, for example, when an error occurs in the reverberation time due to a temporary disturbance, an appropriate reverberation time is confirmed by remeasurement. There is an advantage that you can.

  The reverberation time analysis apparatus according to each of the above aspects is realized by hardware (electronic circuit) such as a DSP (Digital Signal Processor) dedicated to reverberation time analysis, or a general-purpose such as a CPU (Central Processing Unit). This is also realized by cooperation between the arithmetic processing unit and the program. The program of the present invention can be provided in a form stored in a computer-readable recording medium and installed in the computer. The recording medium is, for example, a non-transitory recording medium, and an optical recording medium (optical disk) such as a CD-ROM is a good example, but a known arbitrary one such as a semiconductor recording medium or a magnetic recording medium This type of recording medium can be included. For example, the program of the present invention can be provided in the form of distribution via a communication network and installed in a computer. The present invention is also specified as an operation method (reverberation time analysis method) of the reverberation time analysis apparatus according to each aspect described above.

It is a block diagram of the reverberation time analyzer which concerns on 1st Embodiment of this invention. It is a flowchart of a noise analysis process. It is a flowchart of a reverberation analysis process. It is explanatory drawing of calculation of reverberation time. It is a schematic diagram of an analysis result screen. It is a flowchart of a display control process. It is explanatory drawing of the reverberation analysis process in 2nd Embodiment. It is a schematic diagram of the analysis result screen in 2nd Embodiment.

<First Embodiment>
FIG. 1 is a configuration diagram of a reverberation time analysis apparatus 100 according to the first embodiment of the present invention. The reverberation time analysis apparatus 100 is an information processing apparatus for measuring the reverberation time of an arbitrary acoustic space (measurement space) such as a conference room or a hall. As illustrated in FIG. The present invention is realized by a computer system including the device 12, the display device 14, the input device 16, and the sound collection device 18. For example, the reverberation time analysis apparatus 100 can be realized by a portable information processing apparatus such as a smartphone or a tablet terminal.

  The storage device 12 stores a program executed by the arithmetic processing device 10 and various data used by the arithmetic processing device 10. A known recording medium such as a semiconductor recording medium or a magnetic recording medium or a combination of a plurality of types of recording media can be arbitrarily employed as the storage device 12. The display device 14 (for example, a liquid crystal display panel) displays various images under the control of the arithmetic processing device 10. For example, the reverberation time measurement result is displayed on the display device 14. The input device 16 is an operation device for a user to input an instruction to the reverberation time analysis device 100. For example, an operator that can be pressed by the user or a touch panel configured integrally with the display device 14 is preferably used as the input device 16.

  The sound collection device 18 is a microphone that generates an acoustic signal (hereinafter referred to as “observation signal”) Q by collecting sound in the space to be measured. Although the configuration in which the sound collection device 18 is mounted on the reverberation time analysis device 100 is illustrated in FIG. 1, a sound collection device 18 separate from the reverberation time analysis device 100 may be externally attached to the reverberation time analysis device 100. Is possible. The A / D converter that converts the observation signal Q generated by the sound collection device 18 from analog to digital is not shown for convenience.

  As illustrated in FIG. 1, a sound emission device 200 (speaker) is connected to the reverberation time analysis device 100. An acoustic signal (hereinafter referred to as “test signal”) Z for measuring the reverberation time of the measurement space is supplied from the reverberation time analysis device 100 to the sound emission device 200. The sound emitting device 200 radiates sound (hereinafter referred to as “test sound”) corresponding to the test signal Z supplied from the reverberation time analyzing device 100 to the space to be measured. The D / A converter that converts the test signal Z from digital to analog is not shown for convenience. In addition, although the configuration in which the sound emission device 200 is externally attached to the reverberation time analysis device 100 is illustrated in FIG. 1, a configuration in which the sound emission device 200 is mounted on the reverberation time analysis device 100 may be employed.

  The arithmetic processing device 10 executes a program stored in the storage device 12 to thereby analyze and present the reverberation time of the measurement space (noise analysis unit 22, reverberation analysis unit 24, display control unit). 26). A configuration in which the functions of the arithmetic processing device 10 are distributed to a plurality of devices, or a configuration in which a dedicated electronic circuit realizes a part of the functions of the arithmetic processing device 10 may be employed.

  The noise analysis unit 22 calculates the SN ratio σ [k] in the measured space for each of K different frequency bands B [1] to B [K] (K is a natural number of 2 or more) (k = 1-K). The SN ratio σ [k] of any one frequency band B [k] is an index of the intensity of the component of the frequency band B [k] in the background noise existing in the measured space. The total number K of frequency bands B [k] and the frequency and bandwidth of each frequency band B [k] are arbitrary. For example, the audible frequency band is divided into three (K = 3) frequency bands B [1] to B [3] of the low, middle, and high sound ranges, or 1/1 octave or 1/3 octave. A configuration is adopted in which the audible frequency band is divided into K frequency bands B [1] to B [K] in units of.

  FIG. 2 is a flowchart of processing (noise analysis processing) in which the noise analysis unit 22 calculates the SN ratio σ [k] (σ [1] to σ [K]) of each frequency band B [k]. The noise analysis process of FIG. 2 is started in response to an instruction from the user to the input device 16 (measurement start instruction).

  When the noise analysis process is started, the noise analysis unit 22 converts the level of background noise (hereinafter referred to as “noise level”) LN [k] (LN [1] to LN [K]) in the measured space into the frequency band B [ k] is calculated every time [SA1]. Specifically, the signal level of each frequency band B [k] component of the observation signal Q generated by the sound collection device 18 before the test signal Z is supplied to the sound emitting device 200 (ie, before the test sound is emitted) ( Alternatively, the average value of signal levels over a plurality of time points) is calculated as the noise level LN [k].

  The noise analysis unit 22 radiates the test sound from the sound emitting device 200 by supplying the test signal Z to the sound emitting device 200 (SA2). The type of test sound is arbitrary. For example, a noise signal such as white noise whose signal level is uniform over a wide band, or a time-extended signal (Swept-Sine) whose frequency continuously changes in time is used as the test signal Z. Is preferred. The user can appropriately adjust the signal level of the test signal Z (reproduction volume of the test sound) by operating the input device 16 while listening to the test sound emitted from the sound emitting device 200.

  When the adjustment of the signal level of the test signal Z is completed, the noise analysis unit 22 determines K signals according to the signal level LZ of the adjusted test signal Z and the noise level LN [k] of each frequency band B [k]. The SN ratio σ [k] (σ [1] to σ [K]) is calculated for each of the frequency bands B [1] to B [K] (SA3). The above is a specific example of the noise analysis processing.

  The reverberation analyzer 24 in FIG. 1 measures the reverberation time T [k] (T [1] to T [K]) of the measurement space for each of the K frequency bands B [1] to B [K]. . Specifically, the reverberation analysis unit 24 analyzes the attenuation characteristic of the component in the frequency band B [k] in the observation signal Q immediately after the test sound radiated from the sound emitting device 200 into the measurement target space is stopped. Thus, the reverberation time T [k] is calculated. FIG. 3 is a flowchart of processing (reverberation analysis processing) in which the reverberation analysis unit 24 calculates the reverberation time T [k] (T [1] to T [K]) of each frequency band B [k]. The reverberation analysis process of FIG. 3 is started upon completion of the noise analysis process of FIG.

  When the reverberation analysis process is started, the reverberation analysis unit 24 radiates the test sound from the sound emitting device 200 by supplying the test signal Z having the signal level LZ set in the noise analysis process of FIG. (SB1). The reverberation analysis unit 24 performs a test signal for the sound emitting device 200 at a point in time (hereinafter, referred to as “sounding stop point”) after a predetermined time (for example, a time until the strength of the test sound is stabilized) has elapsed since the start of test sound emission. The supply of Z is stopped and the emission of the test sound is stopped (SB2).

  Immediately after the sound generation stop point, the reverberation sound resulting from the test sound is collected by the sound collection device 18. The reverberation analysis unit 24 identifies the time series of the signal level LQ [k] for each frequency band B [k] by analyzing the observation signal Q supplied from the sound collection device 18 for a predetermined time after the sound generation stop point. Is stored in the storage device 12 (SB3). The time series of the signal level LQ [k] corresponding to any one frequency band B [k] represents the temporal decay of the reverberant sound caused by the test sound.

  The reverberation analyzer 24 calculates the reverberation time T [k] for each frequency band B [k] by analyzing the time series of the signal level LQ [k] of each frequency band B [k] (SB4). The impulse integration method (Schroeder method) is preferably used for calculating the reverberation time T [k]. That is, the reverberation analysis unit 24 performs the reverberation of FIG. 4 using the impulse integration method in which a predetermined interval on the time axis is included in the time series (impulse response) of the signal level LQ [k] of each frequency band B [k]. The attenuation curve C [k] is calculated, and the reverberation time T [k] for each frequency band B [k] is calculated by analyzing the reverberation attenuation curve C [k]. As illustrated in FIG. 4, the reverberation analysis unit 24 of the first embodiment is a time length τ [k] in which the numerical value of the reverberation decay curve C [k] decays by a predetermined reference amount δ after the sounding stop point t0 has elapsed. Accordingly, the reverberation time T [k] of the frequency band B [k] is calculated. Specifically, the value of the reverberation decay curve C [k] is compared with the value at the time t1 from the time t1 when the numerical value is decreased by a predetermined amount (for example, 5 dB) compared to the initial value c0 at the sounding stop point t0. The elapsed time up to the time point t2 when the reference amount δ is reduced is calculated as the time length τ [k]. The reference amount δ is set to 30 dB, for example. Since the reverberation time T [k] is defined as a time length in which the signal level LQ [k] attenuates by 60 dB after the sounding stop point t0 has elapsed, the reverberation analysis unit 24 uses the numerical value of the reverberation attenuation curve C [k]. A value obtained by multiplying the time length τ [k] that attenuates by the reference amount δ by {60 / δ} is calculated as the reverberation time T [k]. For example, assuming that the reference amount δ is 30 dB as described above, a value twice as long as the time length τ [k] is calculated as the reverberation time T [k]. Note that the reverberation time T [k] can be calculated directly from the time series of the signal level LQ [k] of each frequency band B [k] (noise intermittent method).

  The display control unit 26 in FIG. 1 displays the reverberation time T [k] calculated by the reverberation analysis unit 24 on the display device 14 for each frequency band B [k]. Specifically, the display control unit 26 causes the display device 14 to display the analysis result screen 50 of FIG. The analysis result screen 50 is an image for presenting the reverberation time T [k] of each frequency band B [k] to the user. The analysis result screen 50 illustrated in FIG. 5 is displayed in the display area 52 in which the frequency axis (horizontal axis) AX and the numerical axis (vertical axis) AY of the reverberation time T [k] are set for each frequency band B [k]. Is a line graph in which designated points P [k] are arranged and the designated points P [k] are connected to each other by straight lines. The position of the designated point P [k] in the direction of the value axis AY is selected according to the reverberation time T [k].

  The display control unit 26 of the first embodiment includes each frequency band in which the SN ratio σ [k] measured by the noise analysis unit 22 is below a predetermined threshold σTH among the K frequency bands B [1] to B [K]. The reverberation time T [k] of B [k] (hereinafter referred to as “high noise band BN”) is excluded from the display target on the analysis result screen 50. Specifically, for each high noise band BN, the indication point P [k] representing the reverberation time T [k] is omitted. FIG. 5 illustrates a state in which the reverberation time T [1] and the reverberation time T [2] on the low frequency side and the reverberation time T [K] on the high frequency side are excluded from the display target.

  The threshold σTH is set statistically or experimentally so that sufficient reliability is ensured for the reverberation time T [k] measured in an environment where the SN ratio σ [k] exceeds the threshold σTH. That is, the reverberation time T [k] calculated in an environment where the SN ratio σ [k] is low enough to fall below the threshold σTH (that is, an environment where the noise level LN [k] is high) is attributed to background noise in the measured space. There is a high possibility that the measurement result has low reliability including the error. As can be understood from the above description, the display control unit 26 can be rephrased as an element that excludes a measurement result (reverberation time T [k]) with low reliability from the display target. A configuration in which the threshold σTH is variably set according to an instruction from the user to the input device 16 or a configuration in which the threshold σTH is separately set for each frequency band B [k] may be employed.

  FIG. 6 is a flowchart of processing (display control processing) in which the display control unit 26 displays the analysis result screen 50. The display control process of FIG. 6 is started upon completion of the reverberation analysis process of FIG. 3 (calculation of K reverberation times T [1] to T [K]).

  The display control unit 26 selects one of the K frequency bands B [1] to B [K] (hereinafter referred to as “selected band”) B [k] (SC1), and generates noise for the selected band B [k]. It is determined whether or not the SN ratio σ [k] measured by the analysis unit 22 is lower than the threshold σTH (SC2). When the SN ratio σ [k] exceeds the threshold σTH (SC2: NO), the display control unit 26 causes the display device 14 to display the reverberation time T [k] of the selected band B [k]. Specifically, the display control unit 26 arranges the indication point P [k] corresponding to the selected band B [k] in the display area 52 according to the reverberation time T [k] (SC3). On the other hand, when the SN ratio σ [k] is lower than the threshold σTH (that is, when the reverberation time T [k] has low reliability), the display control unit 26 sets the reverberation time T [k] of the selected band B [k]. Excluded from display (SC4). That is, the display control unit 26 does not display the indication point P [k] of the selected band B [k] on the display device 14.

  The display control unit 26 repeats the above processing for each frequency band B [k] (SC5: NO), and when the processing is completed for K frequency bands B [1] to B [K] (SC5) : YES), each indicated point P [k] in the display area 52 is connected with a straight line to complete the analysis result screen 50 (SC6).

  As described above, in the first embodiment, the reverberation time T [k] of each high noise band BN whose SN ratio σ [k] is lower than the threshold σTH is excluded from the display target. There is an advantage that the user can easily grasp the suitability of the measurement result (the reverberation time T [k] to be displayed is sufficiently reliable).

Second Embodiment
A second embodiment of the present invention will be described below. In addition, about the element which an effect | action and function are the same as that of 1st Embodiment in each form illustrated below, the reference | standard referred by description of 1st Embodiment is diverted, and each detailed description is abbreviate | omitted suitably.

  A part (A) in FIG. 7 is a reverberation attenuation curve C [k] in an environment where the SN ratio σ [k] of the frequency band B [k] is high. A part (B) in FIG. This is a reverberation attenuation curve C [k] in an environment where the SN ratio σ [k] is low compared to A). As understood from FIG. 7, in an environment where the S / N ratio σ [k] is low, the reverberation decay curve C [k] (or the time series of the signal level LQ [k]) at an early stage after the sounding stop point t0 has elapsed. There is a tendency that the influence of background noise becomes obvious. Considering the above tendency, in the second embodiment, the reference amount δ is variably controlled according to the SN ratio σ [k] in the space to be measured.

  In the reverberation analysis process, the reverberation analysis unit 24 of the second embodiment reverberation time T [k] so that the reference amount δ [k] decreases as the SN ratio σ [k] of each frequency band B [k] decreases. ] Is calculated individually for each frequency band B [k]. Specifically, the reverberation analyzer 24 sets the reference amount δ [k] to a smaller numerical value as the SN ratio σ [k] calculated by the noise analyzer 22 is lower. For example, when the SN ratio σ [k] is included in the first range, the reference amount δ [k] is set to 30 dB (standard value), and the SN ratio σ [k] is set to the second range below the first range. Is included in the third range below the second range and the SN ratio σ [k] is included in the third range below the second range, the reference amount δ [k] is set to 20 dB. Is set. The reverberation time T [k] (T [k] = τ [k] corresponding to the time length τ [k] in which the numerical value of the reverberation decay curve C [k] decreases by the reference amount δ [k] after the sounding stop point t0 has elapsed. ] × {60 / δ [k]}) is calculated in the same manner as in the first embodiment.

  As described above, by controlling the reference amount δ [k] according to the SN ratio σ [k], the influence of background noise on the measurement result (reverberation time T [k]) is reduced, but the reverberation time T [k] ], The error of the reverberation time T [k] tends to increase (the reliability of the measurement result decreases) as the reference amount δ [k] deviates from 60 dB according to the original definition. In consideration of the above tendency, the display control unit 26 of the second embodiment displays the reverberation time T [k] for each of the K frequency bands B [1] to B [K] on the display device 14. The display modes of the reverberation times T [k] calculated under different reference amounts δ [k] are made different.

  FIG. 8 is a schematic diagram of an analysis result screen 50 in the second embodiment. In FIG. 8, the reference amount δ [1] of the frequency band B [1], the reference amount δ [2] of the frequency band B [2], and the reference amount δ [K] of the frequency band B [K] are set to 20 dB. The reference amount δ [3] of the frequency band B [3] is set to 25 dB, and the reference amount δ [k] of each remaining frequency band B [k] (B [4] to B [K-1]) is set. Is assumed to be set to 30 dB (standard value). As understood from FIG. 8, the display control unit 26 displays the indication point P [k] representing the reverberation time T [k] of each frequency band B [k] according to the reference amount δ [k] ( For example, gradation is displayed. Specifically, the indication point P [k] is displayed with a lighter gradation (a gradation closer to white) as the reference amount δ [k] is smaller. Further, the display control unit 26 sets the reference amount δ [k] in the vicinity of the indicated point P [k] representing the reverberation time T [k] corresponding to the reference amount δ [k] other than the standard value (30 dB). A character string 54 expressing a numerical value is arranged. Specifically, each of the indication point P [1] of the reverberation time T [1], the indication point P [2] of the reverberation time T [2], and the indication point P [K] of the reverberation time T [K]. In the vicinity, a character string 54 of “T20” including the numerical value (20 dB) of each reference amount δ [k] is arranged, and in the vicinity of the indication point P [3] of the reverberation time T [3] A character string 54 of “T25” including a numerical value (25 dB) of δ [3] is arranged.

  As described above, in the second embodiment, the reference amount δ [k] applied to the calculation of the reverberation time T [k] is variably set according to the SN ratio σ [k], and different reference amounts δ. The reverberation time T [k] corresponding to [k] is displayed in a separate display mode. Therefore, there is an advantage that the user can easily grasp whether the measurement result of the reverberation time T [k] is appropriate (reliability of each reverberation time T [k]).

<Third Embodiment>
In the third embodiment, as in the second embodiment (FIG. 8), K reverberation times T [k] are displayed in a display mode corresponding to the reference amount δ [k]. The user appropriately operates the input device 16 to select one of the K frequency bands B [1] to B [K] (any one of the K reverberation times T [1] to T [K]). ) Can be selected. In the configuration in which the touch panel for detecting contact with the display surface of the display device 14 is used as the input device 16, when the user touches a position corresponding to an arbitrary designated point P [k] on the display surface, the designated point It is possible to instruct the selection of the frequency band B [k] corresponding to P [k].

  When any one frequency band (hereinafter referred to as “target band”) B [k] is designated, re-measurement of the reverberation time T [k] corresponding to the target band B [k] is executed. Specifically, the noise analysis unit 22 measures the SN ratio σ [k] of the target band B [k] in the noise analysis process of FIG. 2, and the reverberation analysis unit 24 applies the SN ratio σ [k]. The reverberation time T [k] of the target band B [k] is calculated by the reverberation analysis process of FIG. The display control unit 26 reflects the remeasurement result on the analysis result screen 50. That is, the analysis result screen 50 is updated to the contents including the display of the reverberation time T [k] related to remeasurement.

  In the third embodiment, the same effect as in the second embodiment is realized. In the third embodiment, the reverberation time T [k] of the frequency band B [k] instructed by the user among the K frequency bands B [1] to B [K] is remeasured. For example, there is an advantage that an appropriate reverberation time T [k] can be confirmed by re-measurement when an error occurs in the reverberation time T [k] due to a temporary disturbance. In the above example, the case where the user instructs one of the K frequency bands B [1] to B [K] is illustrated. However, the K frequency bands B [1] to B [K] Of these, the frequency band B [k] in which the reverberation time T [k] is calculated by applying the reference amount δ [k] that is lower than the predetermined threshold (that is, the frequency band B [k] having low reverberation time T [k]). ) Only can be selected by the user.

<Modification>
Each of the above forms can be variously modified. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined.

(1) The aspect of the analysis result screen 50 is not limited to the above example. For example, with respect to the reverberation time T [k] of the frequency band B [k] where the SN ratio σ [k] is lower than the threshold value σTH, a character string for warning that the reliability is low, or remeasurement of the reverberation time T [k]. It is also possible for the display control unit 26 to display the recommended character string on the display device 14. In FIG. 8, the gradation of the designated point P [k] is made different according to the reference amount δ [k]. However, for example, a configuration in which the shape or pattern of the designated point P [k] is made different, A configuration is also employed in which the indicated point P [k] of the reverberation time T [k] with a small amount δ [k] is blinked. As understood from the above description, the “display mode” of the reverberation time T [k] is comprehensively expressed as a visually identifiable property.

(2) The first embodiment and the second embodiment can be merged. That is, the reverberation time T [k] of each frequency band B [k] in which the SN ratio σ [k] is lower than the threshold σTH among the K frequency bands B [1] to B [K] is the same as in the first embodiment. And the display mode of each reverberation time T [k] to be displayed is made different according to the reference amount δ [k] as in the second embodiment. Further, the configuration of the third embodiment in which the reverberation time T [k] of the target band B [k] instructed by the user is remeasured can be applied to the first embodiment. That is, the reverberation time T [k] of the target band B [k] selected by the user among the plurality of frequency bands B [k] whose SN ratio σ [k] is lower than the threshold σTH is remeasured.

(3) In each of the above-described embodiments, the reverberation time analysis device 100 is realized by a portable information processing device such as a smartphone. However, a server device that communicates with a terminal device via a communication network such as a mobile communication network or the Internet (for example, It is also possible to realize the reverberation time analyzing apparatus 100 with a web server). Specifically, the reverberation time analysis apparatus 100 determines the SN ratio σ [k] and the reverberation time T [k] in the frequency band B by analyzing the observation signal Q received from the terminal device in the measured space via the communication network. The analysis result screen 50 is displayed on the display device of the terminal device by measuring every [k] and generating image data of the analysis result screen 50 expressing the measurement result and transmitting it to the terminal device.

DESCRIPTION OF SYMBOLS 100 ... Reverberation time analysis apparatus, 200 ... Sound emission apparatus, 10 ... Arithmetic processing apparatus, 12 ... Memory | storage device, 14 ... Display apparatus, 16 ... Input device, 18 ... Sound collection apparatus, 22 ... Noise analysis unit 24... Reverberation analysis unit 26... Display control unit 50 .. analysis result screen 52.

Claims (3)

Noise analysis means for measuring the S / N ratio in the measured space for each of a plurality of frequency bands;
Reverberation analysis means for measuring reverberation time in the measured space for each of the plurality of frequency bands;
Display means for displaying the reverberation time for each frequency band on a display device, and excluding reverberation time of a frequency band in which the SN ratio is lower than a threshold among the plurality of frequency bands from a display target. Reverberation time analyzer. Noise analysis means for measuring the S / N ratio in the measured space for each of a plurality of frequency bands;
For each of the plurality of frequency bands, the reverberation time of the measured space is set according to the length of time that the sound intensity of the frequency band is attenuated by a reference amount variably set according to the SN ratio of the frequency band. Reverberation analysis means to calculate,
A reverberation time analyzing apparatus comprising: display means for displaying the reverberation time on a display device for each frequency band, and different display modes of the reverberation times measured under different reference amounts. . The reverberation time analysis apparatus according to claim 1 or 2, wherein the reverberation analysis unit remeasures a reverberation time of a frequency band instructed by a user among the plurality of frequency bands.

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