JP2008176044A - Acoustic measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To wirelessly transmit signals of analysis and to accurately match arrival times of a reference signal and a measurement signal. <P>SOLUTION: An acoustic measuring machine 1 measures an acoustic property with a reference signal supplied from a sound source 2 and a measurement signal executed sound pickup with a measuring microphone 5. The measurement signal is wirelessly transmitted to the acoustic measuring machine 1 via a transmitter 6 and a receiver 7. In the transmitter 6, a time stamp for indicating the time of acquiring the measurement signal is imparted to the measurement signal, and then it is wirelessly transmitted. In the acoustic measuring machine 1, the time stamp data can be used as the time when the measurement signal arrives in the main body of the acoustic measuring device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an acoustic measurement device that measures an acoustic characteristic by comparing a reference signal and a measurement signal, and a program for causing a computer to function as the acoustic measurement device.

  As is well known, how the sound emitted from the sound system is heard depends on the state of the sound field (the size and structure of the measurement space, the performance or properties of the sound system, etc.). A conventionally known acoustic measurement device performs analysis by using an audio signal (reference signal) output from a sound source to a sound system and an audio signal (measurement signal) emitted from the sound system. The acoustic characteristics of the sound reaching the measurement point for measuring the signal could be measured (see, for example, Non-Patent Document 1 below).

FIG. 9 shows a configuration example of an acoustic measurement system using a conventionally known acoustic measurement device. In FIG. 9, the acoustic measurement system collects an acoustic measurement device 1, a sound source 2 for supplying a reference signal, a sound system including an amplifier 3 and a speaker 4, and an audio signal emitted from the speaker 4. It is comprised from the microphone 5 for a measurement for this. The output of the sound source 2 is connected to each of the acoustic measuring device 1 and the amplifier 3 via an audio cable and is emitted from the speaker 4 while being supplied to the acoustic measuring device 1. The output of the measurement microphone 5 is connected to the acoustic measurement device 1 via an audio cable, and the audio signal emitted from the speaker 4 is collected by the measurement microphone 5, and the measurement microphone 5 Is supplied to the acoustic measuring instrument 1 via Here, an audio signal directly supplied from the sound source 2 to the acoustic measuring device 1 is a reference signal, and an audio signal supplied to the acoustic measuring device 1 via the microphone 5 is a measuring signal. The sound measuring machine 1 performs analysis using the measurement signal picked up by the microphone 5 and the reference signal output from the sound source 2, and thereby the sound reaching the point (measurement point) where the measurement microphone 5 is installed. The acoustic characteristics can be measured.
http://www.otk.co.jp/file/material/smaarttech1.pdf

  In the conventional measurement system shown in FIG. 9, the installation position of the measurement microphone 5 serves as a measurement point for acoustic characteristics. For this reason, when the distance between the installation position of the acoustic measuring instrument 1 and the installation position of the measurement microphone 5 is far away, a cable for transmitting the measurement signal must be wired over a long distance. Wiring work was troublesome. When measuring the acoustic characteristics of the sound system, it is also important to change the installation position of the microphone 5 and perform measurement at a plurality of measurement points and compare the measurement results for each measurement point. With respect to this point as well, in the conventional measurement system, it is necessary to re-route the cable every time the installation position of the microphone 5 is changed. As described above, in the conventional measurement system, the cable wiring work between the microphone 5 and the acoustic measuring device 1 is complicated, and there is a disadvantage that the measurement work cannot be performed quickly and easily. In particular, the above-mentioned inconvenience is remarkable when the sound field where the acoustic characteristics are to be measured is vast, such as when measuring the acoustic characteristics of a large concert hall.

  If the connection between the acoustic measuring instrument 1 and the measurement microphone 5 is wireless, the inconvenience related to the cable wiring work will be eliminated. The wireless connection itself between the acoustic measuring device 1 and the measurement microphone 5 can be realized only by interposing a transmitter and a receiver for wireless communication between them.

  By the way, when the acoustic measuring device 1 analyzes the reference signal and the measurement signal, the time required for the two audio signals to be analyzed to reach the acoustic measuring device 1 must be matched in order to analyze the same audio signal. Don't be. In the conventional measurement system shown in FIG. 9, the propagation delay time of the measurement signal generated between the speaker 4 and the measurement microphone 5 is obtained, and the delay based on the delay time is obtained from the reference signal input to the acoustic measuring instrument 1. , The time error required for the measurement signal to reach the measurement microphone 5 from the speaker 4 is corrected, and the arrival time of the reference signal and the measurement signal is matched.

  On the other hand, when the connection between the acoustic measuring device 1 and the measurement microphone 5 is made wireless, in addition to the propagation delay time of the measurement signal generated between the speaker 4 and the measurement microphone 5, the AD in the transmitter Processing time for conversion processing, data wireless transmission processing, etc. occurs as a delay time. However, since the processing time in the transmitter is not always constant, there is a possibility that the time required for the entire transmission of the measurement signal may vary. In particular, when the transmitter is configured with a wireless LAN function of a general-purpose personal computer, other operations can also be executed on the multitasking OS installed in the computer, so that the time required for transmission of the measurement signal varies. Can be noticeable. That is, when the connection between the acoustic measuring device 1 and the measurement microphone 5 is made wireless, in addition to the propagation delay time of the measurement signal generated between the speaker 4 and the measurement microphone 5, an uncertain delay time is obtained. Therefore, the time required for the entire transmission of the measurement signal cannot be handled with a constant value. For this reason, the conventional method (method of delaying the reference signal input to the acoustic measuring device 1) has a disadvantage that the arrival time of the reference signal and the measurement signal cannot be correctly matched. Therefore, in order to wirelessly transmit the measurement signal, it is necessary to take measures against variations in the time taken to transmit the measurement signal.

  The present invention has been made in view of the above points. In an acoustic measurement apparatus that measures acoustic characteristics by comparing a reference signal and a measurement signal, the audio signal to be measured is wirelessly transmitted and the reference signal It is an object of the present invention to make it possible to correctly match the arrival times of the measurement signal and the measurement signal.

  The present invention measures acoustic characteristics by comparing two audio signals, a reference signal output from the audio signal generating means to the sound system and a measurement signal obtained by collecting the sound system output by the sound collecting means. A sound measuring device, wherein at least one of the reference signal and the measurement signal is wirelessly transmitted to the main body of the sound measuring device, and the audio signal to be wirelessly transmitted is the sound signal. Time stamp giving means for giving time stamp data representing the time acquired by the sending means to the audio signal, and for receiving the audio signal with time stamp data wirelessly transmitted from the sending means by the main body of the acoustic measurement device And receiving means for receiving the time stamp data by the receiving means. I o signal is an acoustic measuring apparatus characterized by handled as time input to the main body of the acoustic measurement device.

  According to the acoustic measurement device according to the present invention, at least one of the two audio signals (reference signal or the measurement signal) used by the acoustic measurement device to measure the acoustic characteristics is used as the main body of the acoustic measurement device. When wirelessly transmitting to the audio signal, time stamp data indicating the time when the transmission means acquired the audio signal to be wirelessly transmitted is added to the audio signal, and the time-stamped data is transmitted to the audio signal. Treated as the time of arrival at the main body of the measuring device. By wirelessly transmitting at least one of the reference signal and the measurement signal, a physical cable is not required to connect the audio signal of at least one of the reference signal and the measurement signal. Further, the time stamp data to be given to the audio signal to be wirelessly transmitted is the data at the time when the transmission means acquires the audio signal, that is, the processing executed by the transmission means (AD conversion processing, wireless transmission processing, etc. The time data is not affected by the uncertain delay time related to (). Therefore, the time stamp data is regarded as the time when the wirelessly transmitted audio signal reaches the main body of the acoustic measurement apparatus, thereby ignoring the influence of the uncertain delay time related to the processing executed by the transmission means. Thus, only the propagation delay time of the measurement signal generated between the sound system and the sound collecting means can be treated as an error in the time to reach the acoustic measuring device 1 between the reference signal and the measurement signal. . The propagation delay time between the sound system and the sound collecting means can be corrected with a constant value as in the conventional case. Therefore, according to the configuration of the present invention, it is possible to wirelessly transmit at least one of the reference signal and the measurement signal, and to correctly match the arrival times of the reference signal and the measurement signal.

  The present invention can be constructed and implemented not only as a device invention but also as a method invention. Further, the present invention can be implemented in the form of a program of a processor such as a computer or a DSP, or can be implemented in the form of a storage medium storing such a program.

  According to the acoustic measurement device of the present invention, in the configuration in which at least one of the reference signal and the measurement signal is wirelessly transmitted to the main body of the acoustic measurement device, the audio signal to be wirelessly transmitted is transmitted. By giving time stamp data representing the time acquired by the audio signal to the audio signal, the acoustic measurement device that has received this treats the time of the time stamp as the time when the audio signal was input to the main body of the acoustic measurement device. be able to. Therefore, the influence of the uncertain delay time related to the wireless transmission processing of the measurement signal can be ignored, and the reference signal can be simply corrected by correcting the propagation delay time between the speaker 4 and the measurement microphone 5 as in the prior art. And the arrival time of the measurement signal can be matched. Therefore, even in the configuration in which the measurement signal is wirelessly transmitted, the acoustic characteristic can be correctly measured by comparing the reference signal and the measurement signal. Then, by wirelessly transmitting at least one of the reference signal and the measurement signal, the work of cabling work is eliminated, so that measurement of acoustic characteristics at a measurement point at a long distance from the acoustic measurement device and measurement microphone The operation of changing the installation position of the (sound pickup means) can be easily performed, and an excellent effect is achieved that the measurement operation can be performed quickly and easily.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration example of an acoustic measurement system according to this embodiment. In FIG. 1, an acoustic measurement system includes an acoustic measurement device 1, a sound source 2 for supplying a reference signal, a sound system including an amplifier 3 and a speaker 4, and audio emitted from the sound system. It comprises a measuring microphone 5 for picking up a signal, and a transmitter 6 and a receiver 7 for wirelessly transmitting the audio signal picked up by the measuring microphone 5 to the acoustic measuring device 1. In FIG. 1, components surrounded by a dotted line, that is, the acoustic measuring device 1, the transmitter 6, and the receiver 7 correspond to the acoustic measuring device according to claim 1. The configuration of the measurement system shown in FIG. 1 is the conventional acoustic measurement shown in FIG. 9 in that the connection between the acoustic measurement device 1 and the measurement microphone 5 is made wireless via the transmitter 6 and the receiver 7. It is different from the system.

  The acoustic measuring instrument 1 installs the measurement microphone 5 by performing analysis using the audio signal (measurement signal) collected by the measurement microphone 5 and the audio signal (reference signal) output from the sound source 2. The acoustic characteristics such as frequency characteristics can be measured for the sound reaching the point (measurement point). The sound source 2 is a device that supplies an audio signal used for acoustic measurement, and can be constituted by, for example, a CD player, a noise generator, or the like. The output of the sound source 2 is connected to each of the acoustic measuring device 1 and the amplifier 3 through an audio cable, and is emitted from the sound system, but also supplied to the acoustic measuring device 1.

The output of the measurement microphone 5 is connected to the transmitter 6 by wire. The transmitter 6 captures the audio signal collected by the measurement microphone 5 and wirelessly transmits the captured audio signal to the receiver 7. The receiver 7 receives the audio signal wirelessly transmitted from the transmitter 6 and supplies the received audio signal to the acoustic measuring device 1.
For wireless communication performed between the transmitter 6 and the receiver 7, a conventionally known appropriate technique may be applied. For example, when the transmitter 6 and the receiver 7 are composed of general-purpose personal computers, a wireless LAN can be used for wireless transmission of measurement signals.

  When the acoustic measurement device 1 analyzes the reference signal and the measurement signal, it is necessary to match the time required for the two input signals (measurement signal and reference signal) to reach the acoustic measurement device 1. When the measurement signal is transmitted wirelessly, in addition to the propagation delay time of the measurement signal generated between the speaker 4 and the measurement microphone 5, the transmitter 6 performs signal processing such as AD conversion processing and wireless transmission processing. Since such a delay time can occur, the conventional inconvenience that the time required for the entire transmission of the measurement signal cannot be handled with a constant value is as described above. As will be described in detail later, the measurement system according to this embodiment has a feature in the configuration for correctly adjusting the time of the reference signal and the measurement signal in the measurement system that wirelessly transmits the measurement signal.

  In this embodiment, as an example, the acoustic measuring device 1 is constituted by a general-purpose personal computer on which an application program for realizing an acoustic measurement (signal analysis) function to be described later is implemented, and the receiver 7 is configured as described above. It is assumed to be configured by a wireless LAN function (such as a wireless LAN card) provided in a personal computer constituting the acoustic measuring device 1. The transmitter 6 is also composed of a general-purpose personal computer having a wireless LAN function. Therefore, in FIG. 1, a portion surrounded by a dotted line is composed of a personal computer used as the acoustic measuring device 1 and the receiver 7 and a personal computer used as the transmitter 6. Here, as a personal computer applied to the transmitter 6 and the acoustic measuring device 1, a so-called notebook personal computer excellent in portability is preferable. In particular, since the computer applied as the transmitter 6 is frequently moved when the installation position of the measurement microphone 5 is changed, a notebook computer excellent in portability is preferable.

  FIG. 2 is a block diagram showing an example of an electrical hardware configuration of the acoustic measuring device 1. As shown in FIG. 2, the acoustic measuring device 1 includes a microcomputer including a CPU 10, a ROM 11, and a RAM 12. Various programs executed by the CPU 10 are stored in the ROM 11 to RAM 12. The CPU 10 controls the overall operation of the acoustic measuring instrument 1 based on the various programs, and performs an acoustic measurement process and the like according to this embodiment. Or run. Further, the ROM 11 to RAM 12 are provided with a reference signal buffer area for storing a reference signal supplied from the sound source 2 and a measurement signal buffer area for storing a measurement signal taken from the measurement microphone 5. . In addition, the acoustic measuring device 1 is provided with a timer 13, and the time data measured by the timer 13 can be used for clock adjustment processing and time stamp described later. The time data measured by the timer 13 may be an absolute time similar to the time (year / month / day / hour / minute / second) measured by a general clock, or may be a relative time indicating the passage from a certain reference time. May be.

  The acoustic measuring device 1 also includes an input circuit 14 for capturing an audio signal from the outside and a transmission / reception circuit 15 for wireless communication with an external device. The input circuit 14 includes an A / D converter that converts an analog signal into a digital signal. The acoustic measuring instrument 1 handles at least two systems of audio signals: an audio signal (reference signal) output from the sound source 2 and an audio signal (measurement signal) collected by the measurement microphone 5. In the measurement system configuration of FIG. 1, the reference signal is taken into the acoustic measurement device 1 via the input circuit 14, whereas the measurement signal is wirelessly transmitted via the transmitter 6 and the receiver 7. It will be taken into the acoustic measuring instrument 1 via the transmission / reception circuit 15. According to the present invention, as will be described in detail later, the time when the timer 13 counts the data (time stamp) of the time when the reference signal is input when the acoustic measuring device 1 takes in the reference signal via the input circuit 14. The reference signal and the generated time stamp are set as a set and buffered in the buffer area. This time stamp represents the time when the reference signal reaches the acoustic measuring device 1. In the measurement system configuration example of FIG. 1, the function of the transmission / reception circuit 15 in the acoustic measurement device 1 corresponds to the function of the receiver 7.

  The signal analysis circuit 16 is a module that performs analysis using a reference signal and a measurement signal. The signal analysis operation itself by the signal analysis circuit 16 is the same as the signal analysis of a conventionally known acoustic measurement device. It may be. The function of the signal analysis circuit 16 may be realized by a dedicated hardware electric circuit or may be realized by software processing executed by the CPU 10.

  The operation element 18 is a user interface including various switches, a keyboard, a mouse, and the like. The operation of the operation element 18 is detected by the detection circuit 17, and the CPU 10 performs control according to the detected user operation. Execute. The display device 20 is a display composed of an LCD, for example, and the display circuit 19 controls the display of the display device 20 based on an instruction given from the CPU 10. Various windows related to the acoustic measuring device capability are displayed on the display device 20. Various instructions can be input and parameters can be set from the various windows, and measurement results (such as graphs of frequency characteristics) can be monitored.

  Further, the electrical hardware configuration example of the transmitter 6 may be substantially the same as that shown in FIG. The transmitter 6 converts at least an analog audio signal (measurement signal) picked up by the measurement microphone 5 into a digital signal and takes it in, and wirelessly transmits the taken digital signal to the receiver 7. What is necessary is just to have the transmission / reception circuit 15 and the microcomputer for controlling the operation | movement of each part. As will be described in detail later, according to the present invention, the transmitter 6 generates data (time stamp) of the time when the transmitter 6 acquired the measurement signal based on the time counted by the timer 13, and the generation The set time stamp and measurement signal are set and wirelessly transmitted to the receiver 7. Thereby, the acoustic measuring device 1 can handle the time of the time stamp attached to the measurement signal as the time when the measurement signal reaches the acoustic measuring device 1.

  The hardware components of the acoustic measuring device 1 to the transmitter 6 are not limited to the above, and for example, an interface (other I / O) 21 for connecting other devices (for example, other PCs) is further provided. It may be. The other I / O 21 can be used to wire-connect the acoustic measuring device 1 and the transmitter 6 to each other in a clock adjustment process to be described later. When each of the acoustic measuring device 1 to the transmitter 6 is configured by a dedicated hardware device, a remote operation PC may be connected to the interface.

  The operation of this measurement system will be described below with reference to the flowcharts shown in FIGS.

  In the measurement system of this embodiment, as will be described in detail later, the time of the measurement signal and the reference signal is adjusted using the time stamp given to each of the measurement signal and the reference signal. In order for the time adjustment using this time stamp to function correctly, the acoustic measuring device 1 and the transmitter 6 are used as a preparation stage before the acoustic measuring device 1, the transmitter 6 and the receiver 7 are used for acoustic measurement. Therefore, it is necessary to perform processing (clock adjustment) for adjusting each timer 13. In this time setting process, it is arbitrary which time is set based on which of the transmitter 6 and the acoustic measuring device 1 is used. Here, as an example, the acoustic measurement device 1 side is set as a reference for clock adjustment (clock adjustment master), and the clock on the transmitter 6 side (clock adjustment slave) is matched with the time of the clock of the acoustic measurement device 1.

  FIG. 3 is a flowchart illustrating an example of the procedure of the clock setting process. Prior to the clock adjustment process, the acoustic measuring device 1 and the transmitter 6 are connected by wire so that data communication is possible. The user may be able to instruct the start of the time adjustment process by, for example, a predetermined button operation or command input from the master device side. In response to the start instruction from the user, the current time data is transmitted from the acoustic measuring device 1 (master) to the transmitter 6 (slave) (step S1 in FIG. 3). Then, in the transmitter 6, the time of the timer 13 of the own device is updated using the time data received from the acoustic measuring device 1 as the reference time, so that the clock of the acoustic measuring device 1 and the transmitter 6 is adjusted.

  When the clock adjustment process is completed, the acoustic measurement device 1 and the transmitter 6 are disconnected, the measurement microphone 5 is installed at a desired measurement position, and the acoustic measurement can be started. Since the transmitter 6 is wired to the measurement microphone 5, the transmitter 6 is disposed in the vicinity of the measurement microphone 5. According to the measurement system of this embodiment, since the measurement microphone 5 and the acoustic measurement device 1 are wirelessly connected, no audio cable wiring is required between them. Therefore, the installation work of the measurement microphone 5 is simpler than before. Therefore, it is possible to easily change the measurement position.

When an audio signal is output from the sound source 2, the output audio signal is supplied as a reference signal to the acoustic measuring device 1, while being emitted through the amplifier 3 and the speaker 4. The measurement microphone 5 picks up the audio signal emitted from the speaker 4. The audio signal collected by the measurement microphone 5 is supplied to the transmitter 6.
FIG. 4 is a flowchart illustrating an example of a data transmission operation in the transmitter 6. The transmitter 6 acquires an analog audio signal (measurement signal) input from the measurement microphone 5 (step S2), and performs AD conversion processing for converting the acquired analog audio signal into a digital audio signal (step S3).

  In step S4, a time stamp is applied to the measurement signal converted into the digital signal. Here, the time stamp is time data immediately before the AD conversion processing, that is, when the measurement signal is input to the transmitter 6 (AD converter). By this time stamp, the time when the measurement signal is actually measured by the measurement microphone 5 can be specified. Note that since the time data corresponding to the measurement signal converted into the digital signal is actually the time data at the time when the measurement signal is AD converted, the conversion time required for AD conversion work from this time data can be obtained. The time data when the measurement signal is input to the transmitter 6 may be obtained by subtracting.

  In step S5, a unique device ID is assigned to the transmitter 6 to the measurement signal converted into the digital signal. The device ID may be any ID data as long as it can uniquely recognize the individual transmitter 6 in the acoustic measuring device 1. By assigning the device ID to the measurement signal in this way, even if there are a plurality of transmitters 6 in the measurement system, the measurement signal is wirelessly transmitted from one transmitter 6 that is a measurement target. The measurement signal can be received by the acoustic measuring device 1. In step 6, the measurement signal, the time stamp, and the device ID are transmitted as one set. By repeating this process, the transmitter 6 sequentially wirelessly transmits the measurement signals supplied from the measurement microphone 5.

  In this way, by giving the measurement signal the time stamp when the measurement signal is input to the transmitter 6 (AD converter), the AD conversion process (step S2) and the radio transmission process (step S2) in the transmitter 6 are performed. Time data that is not affected by variations in processing time according to S6) can be provided to the acoustic measuring instrument 1. Since the time stamp may be regarded as substantially equivalent to the time when the measurement signal is measured by the measurement microphone 5, the time stamp is treated as the time when the measurement signal reaches the acoustic measuring instrument 1. Thus, the acoustic measuring instrument 1 can obtain time data that does not include an uncertain delay time other than the propagation delay time of the measurement signal generated between the speaker 4 and the measurement microphone 5.

  FIG. 5 is a flowchart showing an example of the operation of the acoustic measuring device 1 that receives the measurement signal wirelessly transmitted by the processing of FIG. When receiving the measurement signal wirelessly transmitted from the transmitter 6 via the receiver 7, the acoustic measuring device 1 analyzes the data of the received measurement signal (step S7). In step S8, based on the device ID included in the analyzed data, it is determined whether or not the transmitter 6 that is the transmission source of the measurement signal is the current device to be measured. That is, in the acoustic measuring instrument 1 (reception side), the ID of the device to be measured is set in advance, and only the measurement signal data corresponding to the set device ID is fetched (YES in step S8), otherwise Is discarded (NO in step S8). Thereby, even when there are a plurality of transmitters 6 on the measurement system, the data wirelessly transmitted from the transmitter 6 to be measured can be specified by the device ID.

  In step S9, the stored measurement signal is buffered in the buffer area to update the stored contents of the buffer area. By repeating this process, the acoustic measuring device 1 can record the measurement signal sequentially wirelessly transmitted from the transmitter 6 as a set with a time stamp in the buffer area. Note that by preparing a buffer area for each device ID, measurement signals transmitted from a plurality of transmitters 6 can be recorded for each transmitter 6. Therefore, for example, if the measurement microphone 5 and the transmitter 6 are installed in advance at each of the plurality of measurement points, the acoustic measurement device 1 can be switched at the plurality of measurement points by simply switching the transmitter 6 to be measured. The collected measurement signal can be captured.

  On the other hand, an example of the operation of the acoustic measuring device 1 that receives the reference signal output from the sound source 2 is as shown in the flowchart of FIG. The acoustic measuring instrument 1 acquires an analog audio signal (reference signal) output from the sound source 2 (step S10), and performs AD conversion processing for converting the acquired analog audio signal into a digital audio signal (step S11). In step S12, a time stamp is added to the reference signal converted into the digital signal. Here, the time stamp is the time immediately before the AD conversion processing, as in the case of the measurement signal, and the reference signal is substantially sent to the input circuit 14 (AD converter) of the acoustic measuring instrument 1. Time data at the time of input. Then, in step S13, the stored reference signal is buffered in the buffer area to update the stored contents of the buffer area. Thus, by repeating this process, the acoustic measuring device 1 can record the reference signal sequentially output from the sound source 2 as a set with a time stamp (time data) in the buffer area.

  Thus, in the acoustic measuring instrument 1, the measurement signal to which the time stamp is given and the reference signal to which the time stamp is given can be recorded. Therefore, in the acoustic measuring device 1, based on the time stamp given to the measurement signal, the time when the transmitter 6 acquired the measurement signal (this is practically the time when the signal was measured by the measurement microphone 5). The time stamp can be treated as the time when the measurement signal reaches the acoustic measuring device 1. Further, the time when the reference signal reaches the acoustic measuring device 1 can be specified based on the time stamp given to the reference signal.

  The acoustic measuring instrument 1 can measure the propagation delay time (delay value) of the measurement signal generated between the speaker 4 and the measurement microphone 5 by the “delay value measurement” function described below. This delay value is used to match the time when the two audio signals (measurement signal and reference signal) to be analyzed arrive at the acoustic measuring device 1. FIG. 7 is a flowchart showing an example of the operation procedure of the “delay value measurement” function executed by the acoustic measuring instrument 1. The “delay value measurement” function is activated by a user manually instructing activation by a predetermined switch operation or command input. A reference signal is acquired from the reference signal buffer area (step S14), and a measurement signal is acquired from the measurement signal buffer area (step S15). In step S16, a calculation for obtaining a delay value is performed using the reference signal and the measurement signal. That is, a transfer function for each signal is obtained by performing an FFT operation on each of the reference signal and the measurement signal, and an impulse response for each signal is obtained by performing an inverse FFT operation on the transfer function for each signal. The delay value indicated by the impulse response of the measurement signal with respect to the impulse response of the reference signal can accurately represent the propagation delay time of the measurement signal generated between the speaker 4 and the measurement microphone 5. In step S17, the delay value obtained by the calculation is stored in the memory. Note that the delay value measurement process itself is the same as a conventionally performed process.

  Next, an example of the operation procedure of the signal analysis (acoustic characteristic measurement) process using the measurement signal and the reference signal executed by the acoustic measuring device 1 will be described with reference to the flowchart shown in FIG. By this analysis processing, for example, the acoustic characteristics of the test system such as the frequency characteristics of the speaker 4 can be measured. This process is started when a user manually gives a start instruction by a predetermined switch operation or command input. In step S18, the delay value recorded in the memory by the process in step S17 of FIG. 7 is read from the memory. In step S19, the set of the measurement signal and time stamp recorded in the measurement signal buffer area by the process of step S9 in FIG. 5 is read.

  In step S20, the time obtained by adding the delay value read in step S18 to the time stamp given to the measurement signal read in step S19 is obtained, and the reference signal is recorded by the process in step S13 of FIG. A reference signal of a time stamp corresponding to the obtained time is read from the signal buffer area. As described above, the time stamp given to the measurement signal substantially corresponds to the time when the measurement signal was measured by the measurement microphone 5. The delay value represents the propagation delay time of the measurement signal generated between the speaker 4 and the measurement microphone 5. Therefore, the reference signal corresponding to the measurement signal can be specified by obtaining the time obtained by adding the delay value to the time stamp given to the measurement signal. In other words, the delay due to the processing time of the wireless transmission of the measurement signal can be ignored by regarding the time of the time stamp given to the measurement signal as the time when the measurement signal arrived at the acoustic measuring device 1. The arrival time of the reference signal and the measurement signal can be matched only by correcting the propagation delay time between the speaker 4 and the measurement microphone 5 as in the prior art. Thus, in the process of step S20, the time when the measurement signal and the reference signal reach the acoustic measuring device 1 can be matched using the time stamps given to the measurement signal and the reference signal.

  In step S21, signal analysis processing is performed using the measurement signal read in step S19 and the reference signal read in step S20, and the result of the analysis is displayed on the display 20 in step S22. In the acoustic measuring instrument 1 according to this embodiment, even when the measurement signal is wirelessly transmitted, the arrival times of the measurement signal and the reference signal are matched based on the time stamps given to the measurement signal and the reference signal. Therefore, the analysis using the measurement signal and the reference signal can be performed correctly.

As described above, according to this embodiment, the time stamp when the measurement signal is input to the transmitter 6 is given to the measurement signal (step S4 in FIG. 4), so that the acoustic measuring instrument 1 Can handle the time of this time stamp as the time when the measurement signal reaches the acoustic measuring device 1. As a result, the influence of the uncertain delay time related to the wireless transmission processing of the measurement signal can be ignored, and the reference can be made by simply correcting the propagation delay time between the speaker 4 and the measurement microphone 5 as in the prior art. The arrival time of the signal and the measurement signal can be matched. Therefore, even in the configuration in which the measurement signal is wirelessly transmitted, the acoustic characteristic can be correctly measured by comparing the reference signal and the measurement signal. By making the measurement signal transmission wireless, there is no need for cable wiring work, so the measurement of acoustic characteristics at a measurement point at a long distance from the acoustic measuring instrument 1, the work of changing the installation position of the measurement microphone 5, etc. This makes it easy to perform measurements, and has an excellent effect that measurement work can be performed quickly and easily.
In addition, since the operation of measuring the acoustic characteristics by the acoustic measuring device 1 is performed after the processing of matching the clocks of the transmitter 6 and the acoustic measuring device 1 in advance (FIG. 3), the time given to the measurement signal by the transmitter 6 The arrival time of the measurement signal and the reference signal using the stamp and the time stamp added to the reference signal by the acoustic measuring device 1 can be correctly matched.

  In the above embodiment, the output (measurement signal) of the measurement microphone 5 is wirelessly connected to the acoustic measurement device 1 and the output (reference signal) of the sound source 2 is wired to the acoustic measurement device 1. However, the present invention is not limited to this, and the output (measurement signal) of the measurement microphone 5 is wired to the acoustic measurement device 1, and the output (reference signal) of the sound source 2 is wirelessly transmitted to the acoustic measurement device 1 via the transmitter 6. It may be configured. Or the structure which carries out radio transmission of both a measurement signal and a reference signal may be sufficient.

  In the above-described embodiment, the sound source 2 is not limited to a device that supplies an audio signal from the outside of the acoustic measuring device 1 such as a CD player or a noise generator, but is configured by a sound source built in the acoustic measuring device 1. May be. For example, in a concert hall or the like, the output of a mixing console (such as an audio signal output from an acoustic device on the stage) can be applied as the sound source 2.

  Moreover, the acoustic measuring device 1, the transmitter 6, and the receiver 7 may be constituted by general-purpose personal computers in which software programs for causing the computer to execute the respective functions are implemented, or the respective functions are realized. It may be configured in the form of a dedicated hardware device for doing this.

The block diagram which shows the structural example of the acoustic measurement system which concerns on this invention. FIG. 2 is a block diagram illustrating an example of an electrical hardware configuration of the measurement apparatus of FIG. 1. The flowchart which shows an example of the procedure of the clock adjustment process of a measuring apparatus and a transmitter. The flowchart which shows an example of the procedure of the operation | movement which a transmitter transmits a measurement signal by radio. The flowchart which shows an example of the procedure of the operation | movement which receives the measurement signal transmitted by radio | wireless in the measuring apparatus. The flowchart which shows an example of the procedure of the operation | movement which receives the reference signal output from the sound source in the measuring apparatus. The flowchart which shows an example of the procedure of the delay value measurement process which a measuring device performs. A flowchart showing an example of a procedure of signal analysis processing using a measurement signal and a reference signal executed by the measurement device; The block diagram which shows the structural example of the measurement system known conventionally.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Acoustic measuring device, 2 Sound source, 3 Amplifier, 4 Speaker, 5 Measurement microphone, 6 Transmitter, 7 Receiver, 10 CPU, 11 ROM, 12 RAM, 13 Timer, 14 Input circuit, 15 Transmission / reception circuit, 16 Signal analysis Circuit, 17 detection circuit, 18 operator, 19 display circuit, 20 display

Claims (5)

An acoustic measurement device that measures acoustic characteristics by comparing two audio signals, a reference signal output from an audio signal generation unit to a sound system and a measurement signal obtained by collecting the output of the sound system by a sound collection unit. There,
Transmitting means for wirelessly transmitting the audio signal of at least one of the reference signal or the measurement signal to the main body of the acoustic measurement device;
Time stamp giving means for giving time stamp data representing the time at which the transmitting means acquired the audio signal to be wirelessly transmitted to the audio signal;
Receiving means for receiving an audio signal with time stamp data wirelessly transmitted from the transmitting means by the main body of the acoustic measuring device;
An acoustic measurement device, wherein the time stamp data is treated as a time at which an audio signal received by the receiving means reaches the main body of the acoustic measurement device.   The acoustic measurement apparatus according to claim 1, further comprising an ID assigning unit that assigns unique ID data to the transmission unit with respect to the audio signal wirelessly transmitted by the transmission unit.   The time stamp assigning means comprises means for calculating time stamp data representing a time when the transmitting means acquires the audio signal based on a time at which AD conversion of the audio signal in the transmitting means is completed. Item 3. The acoustic measurement device according to any one of Items 1 and 2.   Connection means for physically connecting the transmission means and the main body of the acoustic measurement device, and means for time adjustment between the transmission means physically connected by the connection means and the main body of the acoustic measurement device The acoustic measurement device according to claim 1, further comprising: As an acoustic measurement device for measuring acoustic characteristics by comparing two audio signals, a reference signal output from the audio signal generation means to the sound system and a measurement signal obtained by collecting the output of the sound system by the sound collection means A program for operating a computer,
Obtaining at least one of the reference signal and the measurement signal as an audio signal to be wirelessly transmitted;
Providing time stamp data representing the time when the audio signal to be wirelessly transmitted is given to the audio signal;
A procedure for wirelessly transmitting the audio signal to be wirelessly transmitted to the main body of the acoustic measurement device together with the assigned time stamp data;
Receiving a wirelessly transmitted audio signal with time stamp data in the main body of the acoustic measurement device,
A program characterized in that the time stamp data is treated as the time at which the audio signal received by the receiving means reaches the main body of the acoustic measurement device.

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