JP2016119635A - Time difference calculator and terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a time difference calculator for calculating the arrival time difference in voices outputted from respective speakers.SOLUTION: In a time difference calculator (30) for calculating time difference until inspection sounds from different directions reach a predetermined position, generation order of the inspection sounds and generation interval between two inspection sounds whose orders are adjacent to each other are fixed, and a specification part (32) for specifying individual inspection sounds collected at a predetermined position and a calculation part (33) for calculating the time difference until two inspection sounds arrive are provided.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a time difference calculation device that calculates a time difference from when a sound is output from each of a plurality of sound output units until it reaches a predetermined position in space, and a terminal device that includes the time difference calculation device.

  As a conventional technique related to automatic sound field correction of an audio system, for example, Patent Document 1 discloses a sound field correction apparatus that analyzes an impulse response using a TSP (Time Stretched Pulse) signal and obtains a correction coefficient for sound field correction. It is disclosed. In this sound field correction apparatus, a TSP signal is output from a speaker of an audio system, and the TSP signal is collected by arranging a microphone at a position where sound field correction is performed. The TSP signal is collected a plurality of times, and the impulse response is obtained by analyzing with an inverse filter after suppressing the influence of noise by synchronous addition averaging.

  By the way, in recent years, high-quality audio systems having more channels (2.1ch or more) than stereo (2.0ch) sound have begun to spread. In such a stereo system and an audio system of 2.1ch or more, when performing the above-described automatic sound field correction, the frequency characteristics, phase characteristics, etc. of the sound output from the speakers of each channel are adjusted. This adjustment requires calculation of the time difference until the sound output from the speaker of each channel reaches an arbitrary position in the sound field space.

  To find the difference in signal arrival time from the speaker of each channel to an arbitrary position in the sound field space, for example, wired (cable) so that the audio system equipped with these speakers can communicate with the microphone. (See, for example, Patent Document 2), the timing of starting the output of signals from each speaker and the timing of starting the sound collection of each signal output from each speaker can be detected for each speaker. Good. Thereby, since the time until the signal output from each speaker reaches the microphone can be measured, the difference between these times can be calculated.

Japanese Patent No. 4210859 (issued on January 21, 2009) Japanese Patent No. 4435232 (issued on March 17, 2010)

  However, the above-described wired connection is a complicated operation for the user, and it is difficult to say that the user's convenience is taken into consideration. For this reason, it is desired that the above-described time difference can be calculated without connecting the microphone to the audio system by wire.

  When the above-described wired connection is not performed, the microphone side cannot identify which channel of the audio system the collected signal is output from. This is because the timing for starting the output of signals from each speaker and the timing for starting the sound collection of each signal output from each speaker by the microphone cannot be detected for each speaker.

  On the other hand, in the present invention, the signal output from the speaker of each channel of the audio system is detected by any speaker without detecting the timing of starting the output of the signal from each speaker and the timing of starting the sound collection by the microphone. The time difference calculation device can calculate the time difference until the sound output from the speaker of each channel reaches an arbitrary position in the sound field space by making it possible to identify whether the sound is output from And it aims at providing a terminal device.

  In order to solve the above-described problem, the time difference calculation apparatus according to the present invention is configured so that the inspection sound generation order and the inspection sound generation order are adjacent to each other for each inspection sound coming from different directions. Is a time difference calculation device that calculates a time difference between two test sounds that are adjacent in the generation order and that arrive at a predetermined position, and the sound is collected at the predetermined position. A specific unit for identifying each collected test sound based on the sound collection time interval between the test sounds, the generation order of the test sounds, and the time interval between the test sounds, and the specified And a calculation unit that calculates the time difference based on a sound collection time interval between two inspection sounds adjacent to each other in generation order and a generation time interval between the corresponding two inspection sounds.

  In the above configuration, inspection sounds are generated in a predetermined generation order, and inspection sounds arriving from different directions are collected. In addition, the generation time interval between two inspection sounds adjacent to each other in the generation order is determined.

  For this reason, the specifying unit can specify the collected inspection sounds based on the sound collection time interval between the inspection sounds collected at a predetermined position and the generation time interval between the inspection sounds. it can.

  Therefore, the calculation unit can calculate the time difference until each inspection sound reaches a predetermined position based on the sound collection time interval and the generation time interval between the two specified inspection sounds.

  The present invention makes it possible to identify from which speaker the sound output from the speaker of each channel of the audio system is output, so that the sound output from the speaker of each channel is the sound field space. There is an effect that it is possible to calculate a time difference until reaching an arbitrary position.

1 is a schematic diagram showing a schematic configuration of an audio system according to an embodiment of the present invention. It is a block diagram which shows the system configuration | structure of the said audio system. It is a block diagram which shows the function structure of the time difference calculation part which concerns on embodiment of this invention. Output order in which each of the left speaker and the right speaker of the speaker device according to the embodiment of the present invention outputs the inspection sound, and the inspection sound output from the left speaker and the inspection speaker output from the right speaker of the speaker device. It is a schematic diagram which shows an output space | interval. It is a schematic diagram which shows the sound collection space | interval which collected the test | inspection sound output from each of the left speaker and right speaker of the said speaker apparatus with the microphone of the measuring apparatus which concerns on embodiment of this invention. It is a flowchart explaining operation | movement of the said measuring apparatus. It is a flowchart explaining operation | movement of the said time difference calculation part. It is a figure which shows an example of the impulse response computed by the analysis part of the said measuring device. It is a figure which shows an example which computed norm from the impulse response shown in FIG. FIG. 10 is an enlarged view of the vicinity of the first peak, the second peak, and the third peak searched in the norm shown in FIG. 9.

  An embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a schematic diagram showing a schematic configuration of an audio system 1 according to the present embodiment. As shown in FIG. 1, the audio system 1 includes a speaker device 10 (audio output device) and a measurement device 20 (terminal device).

  For example, audio systems that provide a high-quality acoustic space with a plurality of speakers, such as a 5.1ch surround system and a 7.1ch surround system, are widely used. In such an audio system, it is extremely difficult for the user himself / herself to appropriately adjust the frequency characteristics and phase characteristics of the reproduced sound output from a plurality of speakers according to the sound field to obtain an optimal acoustic space full of realism. It is. For this reason, such an audio system includes a so-called automatic sound field correction system that automatically corrects sound field characteristics on the system side to create an optimal acoustic space.

  The audio system 1 includes such an automatic sound field correction system, and can perform sound field correction in a space where the audio system 1 is arranged. The audio system 1 can perform sound field correction processing at the time of sound output by the audio system 1 itself.

  The speaker device 10 is, for example, a television or Bluetooth (registered trademark) Audio, and is an audio output device that outputs at least audio. The speaker device 10 is a sound output device that outputs stereo (2.0 ch) sound, and includes a left speaker 11 and a right speaker 12. In the present embodiment, a stereo sound output device is described as an example of the speaker device 10, but the present invention is not limited to stereo sound. The speaker device 10 may include a plurality of speakers such as a 5.1ch surround system and a 7.1ch surround system.

  The measuring apparatus 20 generates a correction coefficient that is necessary when sound field correction is performed by an automatic sound field correction system provided in the audio system 1. This correction coefficient is for adjusting the frequency characteristic and phase characteristic of each reproduced sound of the left speaker 11 and the right speaker 12 of the speaker device 10. In order to generate the correction coefficient, the measuring device 20 collects the reproduced sounds of the left speaker 11 and the right speaker 12 of the speaker device 10 and measures the level of each reproduced sound. As the measuring device 20, for example, a dedicated terminal such as a remote controller or a portable terminal such as a smartphone can be used.

  In the audio system 1, at the time of measurement for generating the correction coefficient, the speaker device 10 applies a test sound such as a TSP (Time Stretched Pulse) signal in the space where the audio system 1 is arranged to the left to be corrected. Output (generate) from each of the speaker 11 and the right speaker 12.

  And the measuring apparatus 20 collects the above-mentioned test | inspection sound output from each of the left speaker 11 and the right speaker 12 of the speaker apparatus 10 in the user's position in the space where the audio system 1 is arrange | positioned. The measuring device 20 analyzes the collected inspection sound and generates the correction coefficient described above. The speaker device 10 uses the correction coefficient generated by the measurement device 20 to perform sound field correction processing during sound reproduction.

  In such an audio system 1, when the above-described measurement is performed, it is necessary to obtain a time difference until sound output separately from each of the left speaker 11 and the right speaker 12 of the speaker device 10 reaches the user's position. . In other words, the time difference until each voice arriving from different directions reaches the user's position is obtained.

Here, if the user is located in front of the speaker device 10, the distance from the left speaker 11 to the user and the distance from the right speaker 12 to the user are the same. There is no time difference until reaching the user. On the other hand, for example, when the user is at a position where the measurement device 20 shown in FIG. As a result, when sound is output separately from each of the left speaker 11 and the right speaker 12, the time _TL until the sound from the left speaker 11 reaches the user, and the sound from the right speaker 12 is transmitted to the user. between the time T _R to reach, the arrival time difference is a difference in their arrival times (delay difference) = T _L -T _R occurs. Such an arrival time difference is not limited to the position shown in FIG. 1, but the user is in front of the speaker device 10 (a position where the distance from the left speaker 11 to the user is the same as the distance from the right speaker 12 to the user). If it is located, it will inevitably occur.

  By the way, in order to obtain such a difference in arrival time from each speaker to the user, as described in the background art, the sound collected on the measurement device 20 side is the left speaker 11 and the right speaker 12 of the speaker device 10. It is necessary to identify which of these is output from. For this reason, according to the prior art, the audio system and the microphone are connected by wire, and the output start timing of the sound from each speaker, and the sound collection start timing of each signal output from each speaker, Was detected.

  On the other hand, in the audio system 1, the processing for detecting each timing as described above is not required by such a wired connection or a wireless communication connection. In the audio system 1, the measurement device 20 collects which of the left speaker 11 and the right speaker 12 of the speaker device 10 the sound output from the speaker device 10 and collected by the measurement device 20 is output. The measuring device 20 itself can be identified from the sound that has been sounded.

  Hereinafter, in the present embodiment, which is the characteristic part of the present invention, the measurement device 20 outputs which of the left speaker 11 and the right speaker 12 of the speaker device 10 is output from the collected sound. The point of how to identify and calculate the arrival time difference as described above will be mainly described.

  FIG. 2 is a block diagram showing a system configuration of the audio system 1. As shown in FIG. 2, first, the speaker device 10 includes an audio input unit 101, an inspection sound reproduction unit 102, an inspection sound storage unit 103, a reproduction sound selection unit 104, a reception unit 105, and a correction unit 106. , An audio output unit 107, a left speaker 11, and a right speaker 12.

  The audio input unit 101 receives stereo sound output from the left speaker 11 and the right speaker 12. The audio input unit 101 includes, for example, an analog / digital converter, a decoder for decoding a compressed audio signal, and the like.

  The inspection sound reproduction unit 102 reproduces the inspection sound output from each of the left speaker 11 and the right speaker 12 during the above-described measurement by the measurement device 20. The inspection sound storage unit 103 stores the inspection sound.

  The reproduction sound selection unit 104 normally selects the stereo sound output from the audio input unit 101, and selects the inspection sound reproduced from the inspection sound reproduction unit 102 when the measurement device 20 performs the above-described measurement.

  The inspection sound reproducing unit 102 and the reproduced sound selecting unit 104 may not be provided in the speaker device 10. In this case, when performing the above-described measurement, an inspection sound is input to the audio input unit 101.

  The reception unit 105 communicates with the transmission unit 204 of the measurement device 20 and receives the correction coefficient generated by the measurement device 20. In addition, the reception unit 105 receives various commands input by the user using the measurement device 20 from the measurement device 20. When communication with the transmission unit 204 is wireless communication, for example, Bluetooth (registered trademark), WiFi (registered trademark), or the like can be used. Note that communication between the reception unit 105 and the transmission unit 204 may be wired communication.

  The correction unit 106 corrects the stereo sound output from the left speaker 11 and the right speaker 12 using the correction coefficient received by the reception unit 105. By this correction, for example, the speaker characteristics of the left speaker 11 and the right speaker 12 of the speaker device 10, the acoustic space characteristics of the space where the audio system 1 is disposed, and the like are adjusted. If the inspection sound is selected by the reproduction sound selection unit 104, the correction unit 106 outputs the inspection sound input from the reproduction sound selection unit 104 to the audio output unit 107 as it is.

  The audio output unit 107 is connected to the left speaker 11 and the right speaker 12, and normally outputs the audio input from the correction unit 106 to the left speaker 11 and the right speaker 12. On the other hand, during the above-described measurement, the inspection sound input from the correction unit 106 is output to the left speaker 11 and the right speaker 12 at different timings.

  On the other hand, the measuring apparatus 20 includes a microphone 21, a voice input unit 201 (sound collecting unit), an analysis unit 202, a coefficient generation unit 203, and a transmission unit 204.

  The audio input unit 201 is connected to the microphone 21 and collects inspection sounds output from each of the left speaker 11 and the right speaker 12 of the speaker device 10. The voice input unit 201 stores the collected inspection sound in a storage unit (not shown), for example. The voice input unit 201 may output the collected inspection sound to the analysis unit 202 without storing it. The audio input unit 201 includes, for example, an amplifier, an analog / digital converter, and the like.

  The sound collection method of the voice input unit 201 is preferably a monaural method. When stereo sound is collected by two microphones, the cross-correlation is performed between the two sound collection signals, and then one of the plurality of speakers is specified, which increases the calculation amount of the sound collection processing. On the other hand, if the monaural method is used, the above-described processing such as cross-correlation is not necessary, and the amount of calculation is less than that of the stereo method, and the sound collection processing can be performed efficiently.

  The analysis unit 202 analyzes the inspection sound input from the voice input unit 201 and each speaker characteristic of the left speaker 11 and the right speaker 12 of the speaker device 10 and the audio system 1 that are necessary for generating the correction coefficient described above. The acoustic space characteristic of the arranged space is calculated.

  The coefficient generation unit 203 generates a correction coefficient used by the correction unit 106 of the speaker device 10 from the analysis results such as the above-described speaker characteristics and acoustic space characteristics calculated by the analysis unit 202. This correction coefficient is, for example, each set value for delay, volume, equalizer, etc. for the left speaker 11 and the right speaker 12.

  The transmission unit 204 communicates with the reception unit 105 of the speaker device 10 and transmits the correction coefficient generated by the coefficient generation unit 203 to the speaker device 10. The transmission unit 204 transmits various commands input by the user using the measurement device 20 to the speaker device 10. Note that the user may directly input the above-described various commands to the speaker device 10.

FIG. 3 is a block diagram illustrating a functional configuration of the time difference calculation unit 30 (time difference calculation device) according to the present embodiment. As shown in FIG. 2, the time difference calculation unit 30 is included in the analysis unit 202 of the measurement apparatus 20. Specifically, when the inspection sound is output separately from each of the left speaker 11 and the right speaker 12, the time _TL until the inspection sound output from the left speaker 11 reaches the measuring device 20, and the right It realizes the function of calculating the arrival time difference which is a difference between the time T _R until the test sound outputted from the speaker 12 reaches the measuring device 20 (= T L _{-T R).}

  Hereinafter, the configuration and operation of the time difference calculation unit 30 will be described with reference to FIGS. 4 and 5. 4 shows the output order in which the left speaker 11 and the right speaker 12 of the speaker device 10 each output the inspection sound, and the inspection sounds L1, L2, L3,... Output from the left speaker 11 of the speaker device 10. , LM (M is an integer equal to or greater than 2) and output intervals (occurrence time intervals) of inspection sounds R1, R2, R3,..., RM output from the right speaker 12 of the speaker device 10. FIG. 5 is a schematic diagram showing the sound collection interval (sound collection time interval) of the inspection sound output from each of the left speaker 11 and the right speaker 12 of the speaker device 10 and collected by the microphone 21 of the measurement device 20. is there. First, the above-described inspection sound will be described, and then the time difference calculation unit 30 will be described.

  As shown in FIG. 4, when the above-described measurement is started by the measurement device 20, the left speaker 11 (denoted as “Lch” in the drawing) of the speaker device 10 outputs the inspection sound L1 after P (sample) has elapsed. Next, after D (sample) has elapsed since the start of output of the inspection sound L1, the right speaker 12 (indicated as “Rch” in the drawing) of the speaker device 10 outputs the inspection sound R1. And after L (sample) progress from the output start time of the test | inspection sound L1, the left speaker 11 of the speaker apparatus 10 outputs the test | inspection sound L2 again. Thereafter, similarly, the right speaker 12 of the speaker device 10 alternately outputs the inspection sound R2, and the left speaker 11 of the speaker device 10 alternately outputs the inspection sound L3.

  Thus, the output order (generation order) in which the left speaker 11 and the right speaker 12 of the speaker device 10 output the inspection sound is the order of the left speaker 11, the right speaker 12, the left speaker 11, the right speaker 12, and so on. It is determined in advance so that In other words, it is determined in advance so that the cycle of the left speaker 11 → the right speaker 12 is repeated.

  The above-mentioned D, which is the time from the start of the output of the test sound from the left speaker 11 to the start of the output of the test sound from the right speaker 12, first, the test sound from the left speaker 11 to the right speaker 12 in the speaker device 10. Is longer than the time required to reach (or the time required for the inspection sound to reach the left speaker 11 from the right speaker 12). As described above, the arrival time difference, which is the difference between the time until the inspection sound from the left speaker 11 reaches the measuring device 20 and the time until the inspection sound from the right speaker 12 reaches the user, This is due to the difference between the distance from 11 to the measuring device 20 and the distance from the right speaker 12 to the measuring device 20. As shown in FIG. 1, the difference between the two distances is maximum when the measuring device 20, that is, the user exists on an extension of the line segment m connecting the left speaker 11 and the right speaker 12. . Therefore, assuming that the user is located at this position, the above D is a time longer than the time during which the inspection sound propagates between the left speaker 11 and the right speaker 12 (hereinafter referred to as “A”). It has become.

  Next, D mentioned above is longer than the length of the inspection sound (hereinafter referred to as “T”). Further, when performing the above-described measurement by the measuring apparatus 20, the impulse response is calculated from the inspection sound such as a TSP signal, and the above-mentioned D is a reverberation time (hereinafter referred to as “I”) generated during this calculation. It is longer than that).

  Thus, D, which is the time from the start of inspection sound output from the left speaker 11 to the start of inspection sound output from the right speaker 12, propagates between the left speaker 11 and the right speaker 12. The time A is longer than any of the time A to be inspected, the length T of the inspection sound, and the reverberation time I at the time of impulse response calculation. More preferably, the above D is longer than A + T + I. As a result, regardless of the position of the measuring device 20 in the space, the inspection sound is displayed at D, which is the time from the start of output of the inspection sound from the left speaker 11 to the start of output of the inspection sound from the right speaker 12. In addition, there is surely a period of time during which no reverberation sound due to the inspection sound is output. In other words, the inspection sound output from the right speaker 12 immediately after the inspection sound output from the left speaker 11 does not reach the measuring apparatus 20 first.

  The above-mentioned L, which is the time from the start of the output of the inspection sound from the left speaker 11 to the start of the output of the inspection sound from the next left speaker 11, starts the output of the inspection sound (for example, R1) from the right speaker 12. (LD), which is the time from the point in time until the start of the output of the inspection sound (for example, L2) from the next left speaker 11, is longer than D described above. That is, L> 2D.

  As described above, in the output order in which the left speaker 11 and the right speaker 12 of the speaker device 10 described above output the inspection sound, the interval between the start times of the inspection sound output from the adjacent left speaker 11 and right speaker 12 is as follows. , D, (LD), D, (LD),... If such output intervals are arranged in the above output order, an output interval sequence such as output interval (small), output interval (large), output interval (small), output interval (large),. become.

  On the other hand, according to the output order in which each of the left speaker 11 and the right speaker 12 outputs the inspection sound as described above, and the output interval of the inspection sound output from the left speaker 11 and the inspection sound output from the right speaker 12. When the inspection sound is output from each of the left speaker 11 and the right speaker 12 of the speaker device 10, the inspection sound collected by the microphone 21 of the measuring device 20 is as shown in FIG.

  That is, as shown in FIG. 5, the inspection sound output from the left speaker 11 and the inspection sound output from the right speaker 12 are alternately collected. Specifically, the inspection sound L11 output from the left speaker 11 and collected, the inspection sound R11 output from the right speaker 12 and collected, the inspection sound L12 output from the left speaker 11 and collected, The inspection sound R12,... Output from the right speaker 12 and collected.

  Here, it is important how the measurement device 20 identifies which of the left speaker 11 and the right speaker 12 of the speaker device 10 each of the collected inspection sounds is output from. . As described above, the output order in which the left speaker 11 and the right speaker 12 of the speaker device 10 output the inspection sound is the order of the left speaker 11, the right speaker 12, the left speaker 11, the right speaker 12, and so on. , Predetermined. Furthermore, if the intervals at which the inspection sounds are output from the left speaker 11 and the right speaker 12 adjacent to each other in the output order described above are arranged in the output order described above, the output interval (small), the output interval (large), An output interval sequence such as an output interval (small), an output interval (large),.

  Such an output interval sequence is shown in FIG. 5, the interval from the sound collection start time of the inspection sound L11 to the sound collection start time of the inspection sound R11, and the collection of the inspection sound L12 from the sound collection start time of the inspection sound R11. It is also reproduced in the interval until the sound start time, the interval from the start time of sound collection of the inspection sound L12 to the start time of sound collection of the inspection sound R12, and so on. That is, if such intervals are arranged in the order of sound collection, the sound collection intervals such as the sound collection interval (small), the sound collection interval (large), the sound collection interval (small), the sound collection interval (large),. It becomes a column.

  Therefore, by associating the output interval sequence with the sound collection interval sequence, it is possible to specify which of the left speaker 11 and the right speaker 12 of the speaker device 10 is the speaker that outputs each collected test sound. .

  Next, the time difference calculation unit 30 will be described. As illustrated in FIG. 3, the time difference calculation unit 30 includes an extraction unit 31, a specification unit 32, a calculation unit 33, and an inspection sound information storage unit 34.

  The extraction unit 31 has a sound collection interval (small) → a sound collection interval (large) (or a sound collection interval (large) → a sound collection interval (small)) in the inspection sound collected by the microphone 21 of the measuring device 20. Is extracted.

  The identifying unit 32 identifies whether the speaker that has output each collected inspection sound is the left speaker 11 or the right speaker 12 of the speaker device 10 based on the sound collection interval sequence extracted by the extraction unit 31.

  The calculation unit 33 outputs the interval (D + a) between the sound collection start points of the test sound output and collected from each of the left speaker 11 and the right speaker 12 specified by the specification unit 32, and the left speaker 11 and the right speaker. From the difference (a) between the output start time points (D) of the inspection sound output from each of the speakers 12, the inspection sound from each of the left speaker 11 and the right speaker 12 until reaching the measuring device 20. The arrival time difference (a) is calculated.

  The inspection sound information storage unit 34 includes an output order in which the left speaker 11 and the right speaker 12 of the speaker device 10 output the inspection sound, and an interval between the start times of the output of the inspection sound from the left speaker 11 and the right speaker 12. It is stored as inspection sound information.

  The specifying unit 32 and the calculating unit 33 execute the specifying process and the calculating process as described above while referring to the inspection sound information stored in the inspection sound information storage unit 34. Note that the same information as the above-described inspection sound information is also stored in the inspection sound storage unit 103 of the speaker device 10. The inspection sound reproduction unit 102 of the speaker device 10 uses each of the inspection sound information stored in the inspection sound storage unit 103, so that each of the left speaker 11 and the right speaker 12 according to the above output order and output interval is used. Play the inspection sound.

  Hereinafter, the operation of the time difference calculation unit 30 will be described with reference to FIGS. First, the schematic operation of the measurement apparatus 20 including the time difference calculation unit 30 will be described with reference to FIG. FIG. 6 is a flowchart for explaining the operation of the measuring apparatus 20. As shown in FIG. 6, when performing the above-described measurement, the measuring device 20 collects and records the inspection sound sequentially output from the speaker device 10 with the microphone 21 (step S1). The voice input unit 201 outputs the collected inspection sound to the analysis unit 202.

  The analysis unit 202 performs delay measurement (step S2). This delay measurement is a feature of the present invention. This delay measurement is executed by the time difference calculation unit 30.

  The analysis unit 202 performs gain difference measurement (step S3). The analysis unit 202 calculates a relative volume difference between the left speaker 11 and the right speaker 12 of the speaker device 10. The analysis unit 202 calculates each frequency characteristic of the left speaker 11 and the right speaker 12 (step S4). The coefficient generation unit 203 generates a correction coefficient used by the correction unit 106 of the speaker device 10 (step S5). Finally, the transmission unit 204 transmits the correction coefficient to the speaker device 10 (step S6).

  Next, operations of the analysis unit 202 and the time difference calculation unit 30 in step S2 of FIG. 6 will be described. FIG. 7 is a flowchart for explaining the operation of the time difference calculation unit 30.

  As shown in FIG. 7, the analysis unit 202 calculates an impulse response using the inspection sound input from the voice input unit 201 (step S11). If the inspection sound is a TSP signal, the analysis unit 202 calculates an impulse response by convolving a TSP signal (time-reversed TSP signal) obtained by reversing the inspection sound in terms of time. FIG. 8 shows an example of the impulse response calculated by the analysis unit 202.

  The analysis unit 202 calculates the norm of the calculated impulse response (step S12). When obtaining the norm, the absolute value of the impulse response described above may be obtained, or a norm corresponding to a vector length obtained from Hilbert transform or the like may be used. FIG. 9 shows an example of the norm obtained from the impulse response shown in FIG.

  The extraction unit 31 of the time difference calculation unit 30 searches the entire peak for the norm and determines a threshold value of the level value to be determined as the peak (step S13).

  The extraction unit 31 performs the top peak search (step S14), the second peak search (step S15), and the third peak search (step S16) based on the above threshold. The extraction unit 31 may extract a plurality of sets of such three peaks.

  The specifying unit 32 of the time difference calculating unit 30 configures the above-described sound collection interval sequence from the three peaks searched in the above steps S14 to S15. FIG. 10 shows the first peak (hereinafter referred to as “peak 1”), the second peak (hereinafter referred to as “peak 2”), and the third peak (hereinafter referred to as “peak 1”) searched in the norm shown in FIG. It is called “Peak 3”). As shown in FIG. 10, the interval between peak 1 and peak 2 → the interval between peak 2 and peak 3 is the interval (small) → the interval (large). Based on this sound collection interval sequence, the specifying unit 32 outputs the peak 1 to the left speaker 11 (left channel), outputs the peak 2 to the right speaker 12 (right channel), and outputs the peak 3 to the left. The speaker 11 is identified (step S17). The identification unit 32 refers to the above-described inspection sound information stored in the inspection sound information storage unit 34 during the identification process.

  The calculation unit 33 of the time difference calculation unit 30 specifies that the peak 1 is output from the left speaker 11 and the peak 2 is output from the right speaker 12 by the specifying unit 32. Between the left speaker 11 and the right speaker 12 from the difference (a) between the time (D) and the time (D) between the output start times of the test sounds output from the left speaker 11 and the right speaker 12. The arrival time difference (a) until each of the inspection sounds reaches the measuring device 20 is calculated (step S18). The time between peak 1 and peak 2 is D + a.

  In addition, when the extraction unit 31 extracts a plurality of sets of the above-described peaks 1 to 3, the calculation unit 33 may obtain an average of arrival time differences calculated from the respective sets, and the result of the plurality of sets The average may be obtained after removing the error-like result that is greatly deviated from the above, or the median of arrival time differences calculated from each may be adopted.

  In FIG. 6, a series of inspection sounds are recorded and processed in advance. However, if the processing of the analysis unit 202 is in time, the arrival time difference is calculated in real time and the arrival time difference is calculated up to a reliable number of times. Thus, a stop command may be issued to the speaker device 10.

  As described above, in the time difference calculation unit 30 according to the present embodiment, when the inspection sounds are sequentially output from each of the left speaker 11 and the right speaker 12, the output order is determined in advance. The inspection sound output from each of the left speaker 11 and the right speaker 12 is collected. Further, the output interval between the left speaker 11 and the right speaker 12 adjacent to each other in the output order is also determined in advance, whereby the output interval sequence in which the output intervals are arranged in the output order is constant.

  For this reason, the specifying unit 32 arranges the sound collection interval sequence in which the sound collection intervals between the test sounds adjacent in the sound collection order in the measurement device 20 are arranged in the sound collection order, that is, the output order of the left speaker 11 and the right speaker 12. By associating with the output interval sequence, it is possible to specify whether the speaker that has output the collected inspection sound is the left speaker 11 or the right speaker 12.

  Therefore, since the output interval between the specified left speaker 11 and right speaker 12 is determined in advance, the calculation unit 33 determines the left speaker 11 and the right speaker from the difference between this output interval and the above-described sound collection interval. The arrival time difference between the inspection sounds output separately from 12 can be calculated.

  In the above-described embodiment, the speaker device 10 has two speakers, the left speaker 11 and the right speaker 12, but the present invention does not limit the number of speakers to two. The speaker device 10 may include two or more speakers, such as a 5.1ch surround system or a 7.1ch surround system. In this case, in the output order in which each speaker of the speaker device 10 described above outputs the inspection sound, if at least one of the intervals at the start of output of the inspection sound from each adjacent speaker is different from the other, the speaker As in the case of two, each speaker can be specified.

  Further, although the TSP signal is used for the inspection sound, an M-sequence signal may be used instead of the TSP signal.

  Further, the analysis unit 202 and the coefficient generation unit 203 may be provided in the speaker device 10 without being provided in the measurement device 20. In this case, the measuring device 20 collects the inspection sound output from each of the left speaker 11 and the right speaker 12 of the speaker device 10 and transmits the collected inspection sound to the speaker device 10.

  The extraction unit 31, the specifying unit 32, and the calculation unit 33 of the time difference calculation unit 30 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or a CPU (Central Processing Unit) is formed. And may be realized by software.

  In the latter case, the time difference calculation unit 30 includes a CPU that executes instructions of a program that is software that implements each function, and a ROM (Read Only Memory) in which the program and various data are recorded so as to be readable by the computer (or CPU). Alternatively, a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) that expands the program, and the like are provided. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be used for an audio system including a plurality of speakers.

  DESCRIPTION OF SYMBOLS 1 Audio system, 10 Speaker apparatus, 11 Left speaker, 12 Right speaker, 20 Measurement apparatus (terminal device), 21 Microphone, 30 Time difference calculation part (time difference calculation apparatus), 31 Extraction part, 32 Identification part, 33 Calculation part, 34 Inspection sound information storage unit, 101 audio input unit, 102 inspection sound reproduction unit, 103 inspection sound storage unit, 104 reproduction sound selection unit, 105 reception unit, 106 correction unit, 107 audio output unit, 201 audio input unit (sound collection unit) ), 202 analysis unit, 203 coefficient generation unit, 204 transmission unit

Claims (6)

For each inspection sound coming from different directions, the generation order of the inspection sounds and the generation order of the inspection sounds are adjacent to each other, and the generation time interval between the two inspection sounds is determined in advance. A time difference calculation device that calculates a time difference from when an inspection sound is generated to a predetermined position,
Identify each collected test sound based on the sound collection time interval between the test sounds collected at the predetermined position, the generation order of the test sounds, and the time interval between the test sounds. A specific part,
A calculation unit that calculates the time difference based on the specified sound collection time interval between two inspection sounds adjacent to each other in the order of generation and the corresponding generation time interval between the two inspection sounds; A time difference calculation device characterized by the above. The specific part is
2. The time difference calculation according to claim 1, wherein each inspection sound is specified by associating a generation time interval between the inspection sounds with a sound collection time interval between the collected inspection sounds. apparatus. The calculation unit is
The time difference is calculated from the difference between the specified sound collection time interval between the two inspection sounds adjacent to each other in the order of occurrence and the corresponding generation time interval between the two inspection sounds. The time difference calculation apparatus according to claim 1 or 2.   4. The time difference calculation device according to claim 1, wherein at least one generation time interval among the generation time intervals between the inspection sounds is different from other generation time intervals. 5. The time difference calculation device according to any one of claims 1 to 4,
A terminal device comprising: a sound collecting unit for collecting the inspection sound.   The terminal device according to claim 5, wherein the sound collection unit is a monaural sound collection unit.

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