JP2017175442A - Music reproduction device, music reproduction method and music reproduction program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a user of a headphone to confirm sound leakage from the headphone.SOLUTION: A music reproduction device 10 comprises: a signal generation part 31 which generates a measurement signal for measuring a space characteristic; a characteristic acquisition part 32 for acquiring a space characteristic that is obtained by outputting sounds corresponding to the measurement signal from sound output parts; and a reproduction part 40 for reproducing music that is processed based on the space characteristic acquired by the characteristic acquisition part 32. The characteristic acquisition part 32 acquires a first characteristic that is a space characteristic obtained via an ambient space by outputting sounds corresponding to the measurement signal from sound output parts 21L and 21R in a state where a user wears the sound output parts 21L and 21R, and the reproduction part 40 reproduces music that is processed based on the first characteristic.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a music playback device, a music playback method, and a music playback program.

  Sound leakage from headphones and earphones in trains is a problem. In Patent Document 1, the sound leakage condition is calculated for each user in each frequency region, and the volume is automatically adjusted so as not to leak the sound. Further, in Patent Document 2, it is detected that the user wears an earphone or a headphone, and control is performed to stop reproduction when the user is not wearing the earphone or the headphone. In Patent Document 3, sound leakage is prevented by collecting ambient noise with an earphone with a microphone, calculating the attenuation, and adjusting the volume.

JP 2007-88521 A JP 2014-003501 A JP 2012-244522 A

  In order to reduce sound leakage from the headphones, it is desirable for the user to adjust the volume by listening to and confirming the sound leakage. However, a user wearing headphones cannot confirm sound leakage from the headphones, and there is room for improvement.

  The present invention has been made in view of the above, and an object of the present invention is to provide a music playback device, a music playback method, and a music playback program that allow a headphone user to confirm sound leakage from the headphones. That is.

  In order to solve the above-described problems and achieve the object, a music reproducing device according to an embodiment of the present invention includes a signal generation unit that generates a measurement signal for measuring spatial characteristics, and a sound corresponding to the measurement signal. A characteristic acquisition unit that acquires a spatial characteristic obtained by outputting from a sound output unit; and a reproduction unit that reproduces a music piece processed based on the spatial characteristic acquired by the characteristic acquisition unit, the characteristic acquisition unit, The sound output unit outputs a sound corresponding to the measurement signal from the sound output unit with the user wearing the sound output unit, obtains a first characteristic which is a spatial characteristic obtained through a surrounding space, and reproduces the reproduction The unit reproduces the music processed based on the first characteristic.

  According to another aspect of the present invention, there is provided a music playback method including a step of generating a measurement signal for measuring spatial characteristics, and a sound corresponding to the measurement signal with the sound output unit being worn by the user. A step of obtaining a first characteristic, which is a spatial characteristic obtained from the output unit through the surrounding space, and a reproducing unit step of reproducing the music processed based on the first characteristic.

  According to another aspect of the present invention, there is provided a music reproduction program that corresponds to the measurement signal in a state where the computer is equipped with a signal generation unit that generates a measurement signal for measuring spatial characteristics and a sound output unit. Functions as a characteristic acquisition unit that outputs a sound from the sound output unit and acquires a first characteristic that is a spatial characteristic obtained through a surrounding space, and a reproduction unit that reproduces a piece of music processed based on the first characteristic It is a music playback program for making it happen.

  According to the present invention, there is an effect that the user can confirm sound leakage in a state where the headphones are worn while wearing the headphones.

FIG. 1 is a diagram illustrating a configuration example of a music reproducing device according to the first embodiment. FIG. 2 is a diagram illustrating a configuration example of a signal processing unit of the music reproducing device according to the first embodiment. FIG. 3 is a diagram illustrating an example of headphones. FIG. 4 is a diagram showing an outline of the function of the signal processing unit in FIG. FIG. 5 is a flowchart showing an example of processing of the entire music playback device. FIG. 6 is a flowchart illustrating an example of processing when the operation mode of the music playback device is the measurement mode. FIG. 7 is a flowchart showing an example of processing when the music reproducing apparatus is calibrated. FIG. 8 is a flowchart illustrating an example of processing when the operation mode of the music playback device is the measurement mode. FIG. 9 is a flowchart illustrating an example of processing when the operation mode of the music reproducing device is the sound leakage monitor mode. FIG. 10 is a diagram illustrating a configuration example of a music reproducing device according to the second embodiment. FIG. 11 is a diagram illustrating an outline of functions of the signal processing unit in FIG. FIG. 12 is a flowchart showing the operation of the music reproducing device shown in FIGS. 10 and 11. FIG. 13 is a diagram illustrating a configuration example of a music reproducing device according to the third embodiment. FIG. 14 is a diagram showing an outline of the function of the signal processing unit in FIG. FIG. 15 is a flowchart showing the operation of the music reproducing device shown in FIGS. 13 and 14. FIG. 16 is a diagram illustrating a configuration example of a music reproducing device according to the fourth embodiment. FIG. 17 is a diagram showing an outline of functions of the signal processing unit in FIG. FIG. 18 is a flowchart showing the operation of the music reproducing device shown in FIGS. 16 and 17. FIG. 19 is a diagram illustrating a configuration example of a music reproducing device according to the fifth embodiment. FIG. 20 is a diagram showing an outline of functions of the signal processing unit in FIG. FIG. 21 is a flowchart showing the operation of the music reproducing device shown in FIGS. 19 and 20. FIG. 22 is a diagram illustrating a first modification of the music reproducing device. FIG. 23 is a diagram illustrating a third modification of the music reproducing device.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following description of each embodiment, the same or equivalent components as those in the other embodiments are denoted by the same reference numerals, and the description thereof is simplified or omitted. In addition, this invention is not limited by each embodiment. The constituent elements of each embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same. Further, a plurality of modifications described in this embodiment can be arbitrarily combined within the scope obvious to those skilled in the art.

(Configuration of music playback device)
FIG. 1 is a diagram illustrating a configuration example of a music reproducing device 10 according to the first embodiment. As shown in FIG. 1, the music reproducing device 10 includes a display unit 11, an input unit 12, a control unit 13, a storage unit 14, a signal processing unit 15, amplification units 16L, 16R, 17L and 17R, Bus 18.

  The display unit 11 displays various information such as the operation state of the music playback device 10. The input unit 12 is a part operated by the user, and functions as a setting unit for the user to set an operation mode. The input unit 12 receives a user command or the like. The command input by the user is sent to the control unit 13. The music reproducing device 10 may have a touch panel in which the display unit 11 and the input unit 12 are integrated.

  The control unit 13 controls each unit of the music playback device 10. The storage unit 14 stores music data to be reproduced. The storage unit 14 also stores various data used when the control unit 13 controls each unit of the music playback device.

  The signal processing unit 15 converts music data from digital data to analog signals. In addition, the signal processing unit 15 converts the collected sound signals input from the microphones 22L and 22R provided in the headphones 20 from analog signals to digital data. The signal processing unit 15 performs a convolution process between the characteristic acquired by the measurement and the music data to be reproduced. Note that all or part of the signal processing unit 15 can be realized by a DSP (Digital Signal Processor).

  The amplification units 16L and 16R amplify the music signal output from the signal processing unit 15 and output the amplified music signal to the headphones 20. The amplifying units 17L and 17R amplify the collected sound signals input from the microphones 22L and 22R.

  The music reproducing device 10 is connected to the headphones 20. The headphone 20 includes a left channel sound output unit 21L, a right channel sound output unit 21R, a left channel microphone 22L, a right channel microphone 22R, and a switch 23. The music reproducing device 10 outputs music through the sound output units 21L and 21R of the headphones 20. In addition, the music reproducing device 10 collects sound with the microphones 22L and 22R provided in the headphones 20.

  The sound output units 21L and 21R are provided corresponding to the left and right ears of the user so that the user can listen to the music. The sound output units 21L and 21R output sound to the corresponding user's left and right ears. The sound output units 21L and 21R are speaker units that convert input electric signals into sound. The sound output unit 21L outputs a signal obtained by D / A converting and amplifying the left channel data of the music data. The sound output unit 21R outputs a signal obtained by D / A converting and amplifying the right channel data of the music data.

  The microphones 22L and 22R are sound collection units that convert input sound into electrical signals. The microphones 22L and 22R are provided corresponding to the left and right ears of the user. The microphones 22L and 22R collect sound in the space around the left and right ears of the corresponding user. The microphones 22 </ b> L and 22 </ b> R acquire sounds output from the sound output units 21 </ b> L and 21 </ b> R via the space around the user's left and right ears, that is, the space outside the headphones 20.

(Signal processing part)
FIG. 2 is a diagram illustrating a configuration example of the signal processing unit 15 of the music playback device 10. As shown in FIG. 2, the signal processing unit 15 of this example includes a measurement unit 30, a reproduction unit 40, a switch 45, a characteristic storage unit 50, D / A conversion units 61L and 61R, and A / D conversion. Units 71L and 71R, and a mode storage unit 80. The control unit 13 is connected to the measurement unit 30, the reproduction unit 40, the characteristic storage unit 50, the mode storage unit 80, and the storage unit 14 through the bus 18 and realizes data exchange between the respective units.

(Mode memory and operation mode)
The mode storage unit 80 stores mode information. The mode information is information indicating the current operation mode of the music playback device 10. For example, when the user sets an operation mode using the input unit 12, the mode storage unit 80 stores mode information corresponding to the operation mode.

  The operation of the music reproducing device according to the present embodiment includes a measurement mode, a calibration mode, a sound leakage monitor mode, and a normal reproduction mode. In the present embodiment, the operation mode is switched by a user operation. For example, the user may switch the operation mode by operating the input unit 12 while referring to the display content of the display unit 11. Further, a switch for switching the operation mode may be prepared, and the operation mode may be switched when it is detected that the switch has been operated. For example, the switch 23 may have a function of switching the operation mode.

  The measurement mode is a mode for measuring the first characteristic. The first characteristic is a spatial characteristic obtained by outputting sound corresponding to the measurement signal from the sound output units 21L and 21R in a state where the user wears the headphones 20 (hereinafter referred to as characteristic A1). Specifically, the characteristic A1 is a spatial characteristic obtained by acquiring sounds output from the sound output units 21L and 21R with the microphones 22L and 22R through the space around the headphones 20. Since the characteristic A1 is a spatial characteristic including the user's head, it is a unique characteristic for each user. For this reason, when the music reproducing device 10 is shared by a plurality of people such as family members, the characteristic A1 of each user may be stored, and the stored characteristic A1 may be read and used in the sound leakage monitor mode.

  The sound leak monitor mode is an operation mode in which a sound leaked when the user wears the headphones 20 is reproduced. In the sound leak monitor mode, a sound leaked when the user wears the headphones 20 while the user wears the headphones 20 is reproduced.

  The normal playback mode is an operation mode in which music is continuously played back.

(Measurement part)
The measuring unit 30 has a function for measuring the characteristic A1. The measurement unit 30 includes a signal generation unit 31 and a characteristic acquisition unit 32. When the operation mode based on the mode information stored in the mode storage unit 80 is the measurement mode, the measurement unit 30 measures the characteristic A1 using the signal generation unit 31 and the characteristic acquisition unit 32.

  The signal generator 31 outputs measurement data for generating a measurement signal. The measurement signal is a signal for measuring the characteristic A1. The measurement signal is a signal including an audible frequency component. The measurement signal is, for example, an impulse signal, a sweep signal such as TSP (Time Stretched Pulse), a white noise signal, a pink noise signal, or the like. The signal generation unit 31 may output the same measurement data for the left channel and the right channel, or may output different measurement data. The measurement data output from the signal generator 31 is converted into measurement signals that are analog signals by the D / A converters 61L and 61R, and then amplified by the amplifiers 16L and 16R, respectively.

  The characteristic acquisition unit 32 receives the characteristic A1 that has been collected by the microphones 22L and 22R and then converted into digital data by the A / D conversion units 71L and 71R. The characteristic A1 acquired by the measurement unit 30 is stored in the characteristic storage unit 50.

  The characteristic A1 is preferably measured in a quiet place where there is no noise. For example, it is desirable to measure the characteristic A1 immediately after acquisition of the music reproducing device 10 (immediately after purchase, etc.) in a quiet place where there is no noise, such as at home.

(Playback part)
The reproduction unit 40 includes a mode control unit 41, switches 42a and 42b, reproduction processing units 43a and 43b, and convolution processing units 44a and 44b. The mode control unit 41 controls the switches 42 a and 42 b according to the mode information stored in the mode storage unit 80.

  The switch 42a receives the data of the left channel L among the music data stored in the storage unit 14. The switch 42a outputs the input data to the reproduction processing unit 43a or the convolution processing unit 44a.

  The switch 42 b receives the data of the right channel R among the music data stored in the storage unit 14. The switch 42b outputs the input data to the reproduction processing unit 43b or the convolution processing unit 44b.

  When the operation mode based on the mode information stored in the mode storage unit 80 is the sound leakage monitor mode, the mode control unit 41 controls the switches 42a and 42b, and among the music data stored in the storage unit 14, The left channel L data is input to the convolution processing unit 44a, and the right channel R data is input to the convolution processing unit 44b.

  When the operation mode based on the mode information stored in the mode storage unit 80 is the normal reproduction mode, the mode control unit 41 reproduces the data of the left channel L among the music data stored in the storage unit 14. 43a, and the right channel R data is input to the reproduction processing unit 43b.

  The reproduction processing units 43a and 43b include a buffer that temporarily stores music data to be reproduced. The reproduction processing units 43a and 43b input the music data stored in the buffer to the D / A conversion units 61L and 61R via the switch 45.

  The convolution processing units 44a and 44b include a buffer for temporarily storing music data. The convolution processing units 44a and 44b perform convolution processing between the music data stored in the buffer and the characteristic A1. The convolution processing units 44a and 44b input the music data subjected to the convolution processing to the D / A conversion units 61L and 61R via the switch 45.

  The switch 45 outputs the music data input from the reproduction processing units 43a and 43b or the convolution processing units 44a and 44b to the D / A conversion units 61L and 61R. The analog signal converted by the D / A conversion unit 61L is input to the amplification unit 16L. The analog signal converted by the D / A converter 61R is input to the amplifier 16R.

(headphone)
FIG. 3 is a diagram illustrating an example of the headphones 20. FIG. 3 schematically shows the headphones 20. As shown in FIG. 3, the headphone 20 includes a left channel sound output unit 21L, a right channel sound output unit 21R, a left channel microphone 22L, a right channel microphone 22R, and a switch 23. And a headband portion 24.

  The headband unit 24 is a part worn by the user on the head. The headband unit 24 can be adjusted in length in order to be properly worn on the user's head.

  The left channel sound output unit 21L and microphone 22L are provided at the left end 24L of the headband unit 24, and the right channel sound output unit 21R and microphone 22R are provided at the right end 24R of the headband unit 24, respectively. The sound output units 21L and 21R of the headphone 20 are located near the auricle when worn by the user. The microphones 22L and 22R are also desirably located near the pinna when worn by the user.

  The switch 23 is operated by the user. When the user operates the switch 23, the signal output from the switch 45 in the music playback device is switched.

  Note that FIG. 3 illustrates the headphones that exchange signals with the music reproducing device 10 via a wire, that is, a cable, but headphones that exchange signals with the music reproducing device 10 may be used.

(Outline of signal processor function)
FIG. 4 is a diagram showing an outline of the function of the signal processing unit 15 in FIG. As shown in FIG. 4, the signal processing unit 15 includes a switch 45. The switch 45 switches signals of the three systems of terminals 1L and 1R, terminals 2L and 2R, and terminals 3L and 3R based on the switching signal. The switching signal is output from the control unit 13, for example. The switch 23 provided on the headphone 20 side may have a function of outputting a switching signal.

  The output side of the switch 45 is connected to the amplifying unit 16. The amplifying unit 16 functions as a headphone amplifier. The amplifying unit 16 includes an amplifying unit 16L for the L channel and an amplifying unit 16R for the R channel. The switch 45 connects the terminals 1 </ b> L and 1 </ b> R to the amplification unit 16 when outputting the measurement signal generated by the signal generation unit 31 of the measurement unit 30. The switch 45 connects the terminals 2 </ b> L and 2 </ b> R to the amplification unit 16 when reproducing an audio signal in the sound leakage monitor mode. The switch 45 connects the terminals 3L and 3R to the amplifying unit 16 when reproducing the audio signal in the normal reproduction mode.

  The amplifying unit 16 can change the amplification factor according to the volume signal. For example, when the user operates the input unit 12, the control unit 13 outputs a volume signal. The switch 23 provided on the headphone 20 side may be configured as a rotary switch and may have a function of outputting a signal for setting the volume. In FIG. 4, the amplifying unit 17L and the amplifying unit 17R are collectively referred to as “amplifying unit 17”. In the following description, it may be referred to as “amplifying unit 17”.

(Processing of the entire device)
FIG. 5 is a flowchart illustrating an example of processing of the entire music playback device 10.

  In step S11, it is determined whether or not the characteristic A1 has been acquired in the music reproducing device 10. If it is determined in step S11 that the characteristic A1 has not been acquired (No in step S11), the process proceeds to step S12. In step S12, the characteristic A1 is measured. In step S13, the characteristic A1 measured in step S12 is stored. In step S14, the music processed based on the characteristic A1 stored in step S13 is reproduced.

  If it is determined in step S11 that the characteristic A1 has been acquired (Yes in step S11), the process proceeds to step S14.

(Measurement mode)
In the measurement mode, the measurement unit 30 acquires a spatial characteristic in a state where the user wears the headphones on the head and stores the spatial characteristic in the characteristic storage unit 50. Specifically, with the user wearing headphones, the gain αhp of the amplifying unit 16 that is a headphone amplifier and the gain αmic of the amplifying unit 17 that is a microphone amplifier are set, and the switch 45 is connected to the terminals 1L and 1R. Then, impulses are output to the sound output units 21L and 21R of the headphones 20 to obtain responses.

  Next, the operation of the music playback device 10 when the operation mode is the measurement mode will be described. FIG. 6 is a flowchart illustrating an example of processing when the operation mode of the music playback device 10 is the measurement mode. FIG. 6 is a flowchart illustrating an example of a process for measuring the characteristic A1 in step S12 of FIG.

  In FIG. 6, in step S121, it is determined whether or not there is a measurement start request from the user. In step S121, when the user wears the headphones 20 and there is a measurement start request (Yes in step S121), the process proceeds to step S122. In step S122, a measurement start request is sent to the measurement unit 30 for the characteristic A1. In step S123, the measurement unit 30 outputs a measurement signal, and the sound output units 21L and 21R output the measurement signal as sound.

  In step S124, sounds output from the sound output units 21L and 21R are input (collected) to the microphones 22L and 22R through the surrounding space, and the characteristic A1 is acquired. In step S121, when there is no measurement start instruction from the user (No in step S121), the process returns to step S121.

(Proofreading)
The music player 10 is preferably calibrated so that ambient sounds can be heard at the same level. The calibration is performed, for example, at the time of manufacturing the music reproducing apparatus 10 or before shipping.

  The calibration is performed as follows, for example. That is, a pure sound of 1 kHz is reproduced by a speaker (not shown), and the reproduction volume or distance of the speaker is adjusted so that the sound pressure level becomes 80 [dB] with a sound level meter at the ear. Next, the headphones 20 are attached in this state, and the signals input to the built-in microphones 22L and 22R are made to be audible as they are from the headphones 20. The amplification factor αmic of the amplifying unit 17 that is a microphone amplifier is set so that the signals input to the microphones 22L and 22R have a signal level of, for example, −20 [dB] (this level is a reference level).

  Next, the input pure tone signal of 1 [kHz] is reproduced by the sound output units 21L and 21R of the headphone 20, and amplified by the amplifying unit 16 which is a headphone amplifier (not shown) so as to be 80 [dB] at the ear. Adjust the rate αhp. The amplification factor αhp and the amplification factor αmic at this time are stored. The amplification factor αhp may be set to a level suitable for music playback of the headphones 20.

  FIG. 7 is a flowchart illustrating an example of processing when the music reproducing device 10 is calibrated. In step S101, a single frequency pure tone is output from a speaker (not shown). For example, a CD (Compact Disc) on which a pure sound of 1 [kHz] is recorded is prepared, and the reproduction sound of the CD is reproduced by a speaker (not shown).

  In step S102, a sound level meter (not shown) is used to set a predetermined volume at the ear (for example, the sound pressure level at the ear is a sound pressure level of 80 [dB]). At this time, the sound volume is set so that the user normally listens. For example, the volume is set to 80 [dB] at the ear, or the volume knob is adjusted.

  In step S103, the user wears the headphones 20 and enters a recording state. In step S104, the amplification factor αmic of the amplification unit 17 that is a microphone amplifier is adjusted so that a predetermined signal level is obtained. Here, for example, the signal level is adjusted to “−20 [dB]” as in step S105. Until the predetermined signal level is obtained, the amplification factor αmic of the amplification unit 17 that is a microphone amplifier is adjusted (No in step S105, step S104).

  If a predetermined signal level is obtained (Yes in step S105), in step S106, the amplification factor αmic of the amplification unit 17 that is a microphone amplifier is stored.

  In step S107, the amplification factor of the amplification unit 16 that is a headphone amplifier is adjusted so that a predetermined sound pressure level is obtained. The amplification factors of the amplification units 16L and 16R, which are headphone amplifiers, are adjusted until a predetermined sound pressure level is obtained (No in step S108, step S107).

  If the sound pressure level same as that in step S102, that is, 80 [dB] is obtained inside the headphones 20 using the sound level meter (Yes in step S108), the amplification factor αhp of the amplifying unit 16 that is a headphone amplifier is obtained in step S109. Remember.

(Measurement mode)
The measurement unit 30 acquires spatial characteristics in a state where the headphones 20 are worn on the user's head. Specifically, with the user wearing the headphones 20, the amplification factor αhp of the amplification unit 16 that is a headphone amplifier and the amplification factor αmic of the amplification unit 17 that is a microphone amplifier are set, and the switch 45 is connected to the terminals 1L and 1R. The impulse is connected and output from the sound output units 21L and 21R of the headphones 20, and a response is acquired. In this way, the characteristic A1 is obtained.

  FIG. 8 is a flowchart illustrating an example of processing when the operation mode of the music playback device is the measurement mode. The process of FIG. 8 corresponds to the process of step S12 described above. In step S201, the signal processing unit 15 determines whether or not to perform sound leakage measurement. When sound leakage measurement is performed (Yes in Step S201), the process proceeds to Step S202, and the signal processing unit 15 connects the switch 45 to the terminals 1L and 1R.

  In step S203, a sound based on the measurement signal generated by the signal generation unit 31 is output from the sound output unit, and the impulse response is measured. In step S204, the measurement result in step S203 is stored in the characteristic storage unit 50 as the characteristic A1.

  If sound leakage measurement is not performed in step S201 (No in step S201), the process proceeds to step S205, and the normal playback mode is set. In step S205, the signal processing unit 15 connects the switch 45 to the terminals 3L and 3R. In step S206, the audio signal is reproduced.

  In step S207, the signal processing unit 15 determines whether or not a reproduction stop request has been input. In step S207, when a reproduction stop request is input (Yes in step S207), the signal processing unit 15 stops reproduction, and the process ends. In step S207, if a reproduction stop request is not input (No in step S207), the process returns to step S206, and signal reproduction is continued.

(Normal playback mode)
Usually, when listening to music, the switch 45 is connected to the terminals 3L and 3R. Thereby, the music data output from the storage unit 14 is output from the sound output units 21L and 21R of the headphones 20. When the sound leak monitor button is pressed during music playback, the sound leak monitor mode is set.

(Sound leak monitor mode)
In the sound leak monitor mode, the convolution processing units 44a and 44b perform a process of convolving the characteristic A1 into the L channel and the R channel of the audio signal. In the sound leak monitor mode, the switch 45 is switched to the terminals 2L and 2R, and the music signal in which the characteristic A1 is convoluted is reproduced by the headphones 20. While wearing headphones, you can listen to the sound leaked from the headphones. At this time, if the volume of the amplifying unit 16 which is a headphone amplifier is changed, the playback volume of the music signal in which the characteristic A1 is convoluted is changed accordingly, and the sound leakage state corresponding to the playback volume can be confirmed.

  FIG. 9 is a flowchart illustrating an example of processing when the operation mode of the music reproducing device is the sound leakage monitor mode. In step S301, the signal processing unit 15 determines whether to perform sound leakage monitoring. When sound leakage monitoring is performed (Yes in step S301), the process proceeds to step S302, and the signal processing unit 15 connects the switch 45 to the terminals 2L and 2R.

  In step S303, the signal processing unit 15 performs a process of convolving the characteristic A1 on the audio signal, and reproduces the audio signal in which the characteristic A1 is convolved in step S304. In step S305, the signal processing unit 15 determines whether or not a reproduction stop request has been input. In step S305, when a request to stop playback is input (Yes in step S305), the signal processing unit 15 stops playback, and the process ends. In step S305, when the reproduction stop request is not input (No in step S305), the process returns to step S304, and the signal reproduction is continuously performed.

  If sound leakage monitoring is not performed in step S301 (No in step S301), the process proceeds to step S205, and the normal playback mode is set. The subsequent processing is the same as the processing in steps S205 to S207 described with reference to FIG.

  In step S301, sound leakage monitoring may be performed when the ambient sound has changed. For example, sound leakage monitoring should be performed when a railway vehicle on which a user is riding enters a tunnel and the ambient sound becomes louder, or when the user has stopped for a long time to adjust the time and the ambient sound becomes louder. May be. In order to realize this, it is only necessary to periodically compare the ambient sound with a predetermined threshold value.

(Eliminates the characteristics of the ear canal)
FIG. 10 is a diagram illustrating a configuration example of a music reproducing device according to the second embodiment. FIG. 11 is a diagram showing an outline of the function of the signal processing unit 15 in FIG. 10, the music reproducing device according to the present embodiment has a configuration in which an inverse filter calculation unit 81 is added to the device of FIG. The inverse filter calculation unit 81 is connected to the bus 18 and is controlled by the control unit 13.

  In FIG. 11, the measurement unit 30 sends a measurement result similar to the process described with reference to FIG. 8 to the inverse filter calculation unit 81 using an ear microphone (not shown). The inverse filter calculation unit 81 calculates the ear canal correction characteristic A2 based on the result measured by the ear microphone. The ear canal correction characteristic A2 calculated by the inverse filter calculation unit 81 is stored in the inverse filter calculation unit 81, for example. The ear microphone has a shape that can be inserted into the holes of the user's ears, that is, the ear canals of both ears. By using the ear microphone, it is possible to acquire the acoustic characteristics of the ear canal of both ears of the user wearing the headphones.

  In the second embodiment, the convolution processing units 44a and 44b perform a convolution process on the music data based on the characteristic A1, and further performs a convolution process based on the ear canal correction characteristic A2. By doing so, it is possible to output the sound after performing correction for removing the user's external auditory canal characteristics. By outputting the sound from which the user's external auditory canal characteristic has been removed, it is possible to hear a sound that is closer to the leakage sound heard by others other than the user.

  FIG. 12 is a flowchart showing the operation of the music reproducing device shown in FIGS. 10 and 11. In FIG. 12, in step S401, the signal processing unit 15 determines whether or not to perform sound leakage monitoring. When sound leakage monitoring is performed (Yes in step S401), the process proceeds to step S402, and the signal processing unit 15 connects the switch 45 to the terminals 2L and 2R.

  In step S403, the signal processing unit 15 performs a process of convolving the characteristic A1 on the audio signal that is music data. A signal obtained by this convolution processing is defined as signal B1. In step S404, the signal processing unit 15 performs a process of convolving the ear canal correction characteristic A2 with the signal B1.

  In step S405, the signal processing unit 15 reproduces a signal in which the characteristic A1 and the ear canal correction characteristic A2 are convoluted. In step S406, the signal processing unit 15 determines whether or not a reproduction stop request has been input. In step S406, when a request for stopping playback is input (Yes in step S406), the signal processing unit 15 stops playback, and the processing ends. In step S406, if a reproduction stop request is not input (No in step S406), the process returns to step S405, and signal reproduction is continued.

  If sound leakage monitoring is not performed in step S401 (No in step S401), the process proceeds to step S205, and the normal playback mode is set. The subsequent processing is the same as the processing in steps S205 to S207 described with reference to FIG.

(Noise level display)
FIG. 13 is a diagram illustrating a configuration example of a music reproducing device according to the third embodiment. FIG. 14 is a diagram showing an outline of the function of the signal processing unit 15 in FIG. In FIG. 13, the music reproducing apparatus according to the present embodiment has a configuration in which a noise level calculation unit 82 is added to the apparatus of FIG. The noise level calculation unit 82 is connected to the bus 18 and is controlled by the control unit 13. The noise level calculation unit 82 receives the output signals of the amplification units 16L and 16R as inputs.

  In FIG. 14, the noise level calculation unit 82 calculates the noise level based on the output signals of the amplification units 16L and 16R. The noise level calculation unit 82 calculates a noise level by applying a predetermined filter characteristic. For example, “A characteristic” is used as the filter characteristic. The “A-characteristic” is a frequency weighting characteristic in consideration of human hearing, which is used for measurement by a sound level meter, and is defined in JIS (Japanese Industrial Standards) C 1509-1 “Normal noise type”.

  The noise level calculated by the noise level calculation unit 82 may be displayed on the display unit 11 by the control unit 13. The display of the noise level by the control unit 13 may be displayed as a numerical value, or may be displayed in a multi-stage evaluation (for example, a 5-stage evaluation) based on a comparison result with a plurality of types of threshold values. You may display a noise level using a color and a figure.

  Here, when the signal level is −20 [dB] with the amplification factor αhp of the amplification unit 16 that is a headphone amplifier and the amplification factor αmic of the amplification unit 17 that is a microphone amplifier, the sound pressure level is 80 [ dB], the noise level can be calculated with an increase / decrease amount of the music signal of −20 [dB]. If the amplification factor of the amplifying unit 16 which is a headphone amplifier is not αhp, the calculation is performed in consideration of the increase / decrease amount.

  FIG. 15 is a flowchart showing the operation of the music reproducing device shown in FIGS. 13 and 14. In FIG. 15, in step S501, the signal processing unit 15 determines whether to perform sound leakage monitoring. When sound leakage monitoring is performed (Yes in step S501), the process proceeds to step S502, and the signal processing unit 15 connects the switch 45 to the terminals 2L and 2R.

  In step S503, the signal processing unit 15 performs a process of convolving the characteristic A1 on the audio signal that is the music data. A signal obtained by this convolution processing is defined as signal B1. In step S504, the signal processing unit 15 reproduces the signal in which the characteristic A1 is convoluted.

  In step S505, the signal processing unit 15 determines whether or not to display the noise level. When displaying the noise level (Yes in step S505), the process proceeds to step S506, and the signal processing unit 15 performs a process of convolving “A characteristic” with the signal B1. A signal obtained by this convolution processing is defined as a signal C1. In step S507, the signal processing unit 15 calculates a noise level for the signal C1. For example, when the signal level of 1 [kHz] is a signal level of −20 [dB] and the sound pressure level is 80 [dB], the amplification factor of the headphone amplifier 16 is amplified to the amplitude of the signal C1 when the amplification factor is αp. The rate αp / αhp is multiplied to determine the signal level, and the difference from the reference level of −20 [dB] is added to 80 [dB].

  In step S508, the control unit 13 displays the calculated noise level on the display unit 11. Thereafter, in step S509, the signal processing unit 15 determines whether there is a request to stop reproduction. When the reproduction is stopped (Yes in step S509), the process ends.

  In step S509, when there is no request to stop reproduction (No in step S509), the process returns to step S504, and the signal processing unit 15 continues reproduction. If the noise level is not displayed in step S505 (No in step S505), the process proceeds to step S509. In step S509, the same processing as described above is performed.

  When sound leakage monitoring is not performed in step S501 (No in step S501), the process proceeds to step S205, and the normal playback mode is set. The subsequent processing is the same as the processing in steps S205 to S207 described with reference to FIG.

(Display noise level considering distance)
FIG. 16 is a diagram illustrating a configuration example of a music reproducing device according to the fourth embodiment. FIG. 17 is a diagram showing an outline of functions of the signal processing unit 15 in FIG. In FIG. 16, the music reproducing device according to the present embodiment has a configuration in which attenuation units 83a and 83b are added to the device of FIG. Attenuators 83a and 83b attenuate the signal after the convolution process.

  In FIG. 17, attenuation units 83a and 83b are provided corresponding to the convolution processing units 44a and 44b. The attenuating units 83a and 83b receive the output signals of the convolution processing units 44a and 44b as inputs, and attenuate the attenuation signals based on the input distance data 830. Thereby, it is possible to hear a leak sound at a position away from the user's position. The distance data 830 is data indicating a distance to a position away from the own apparatus, that is, the music reproducing apparatus 10. The distance data 830 is input by, for example, the user operating the input unit 12. In this case, the input unit 12 has a function as a distance input unit. In addition, while outputting a leak sound, the control part 13 may display the value of distance on the display part 11. FIG.

When the user wearing the headphones confirms the sound leakage at a position away from himself / herself, the attenuation units 83a and 83b use the value r of the distance data 830 input from the input unit 12, for example, The attenuation amount β is calculated based on the following equation (1).
β = 20 · log r [dB] (1)
Equation (1) indicates that the sound pressure level decreases by 6 [dB] when the value r of the distance data 830 is doubled. Based on the equation (1), the attenuation units 83a and 83b calculate the attenuation amount β, and attenuate the amplitudes of the outputs of the convolution processing units 44a and 44b.

  FIG. 18 is a flowchart showing the operation of the music reproducing device shown in FIGS. 16 and 17. In FIG. 18, the processing from step S601 to step S604 is the same as the processing from step S501 to step S504 in FIG.

  In step S605, the signal processing unit 15 determines whether or not the distance data 830 is input. When the distance data 830 is input (Yes in step S605), the process proceeds to step S606, and the signal processing unit 15 calculates the attenuation β based on the above equation (1). In step S607, the signal processing unit 15 attenuates the signal B1 by the attenuation amount β. Thereafter, the signal processing unit 15 returns to Step S604.

  If there is no input of distance data 830 in step S605 (No in step S605), in step S608, the signal processing unit 15 determines whether there is a request to stop reproduction. If playback is to be stopped (Yes in step S608), the process ends.

  In step S608, when there is no request to stop the reproduction (No in step S608), the process returns to step S604, and the signal processing unit 15 continues the reproduction. When sound leakage monitoring is not performed in step S601 (No in step S601), the process proceeds to step S205, and the normal playback mode is set. The subsequent processing is the same as the processing in steps S205 to S207 described with reference to FIG.

  In the above, the case where the sound attenuated according to the value of the input distance data 830 is output has been described. However, in order to reduce the leaked sound by [dB] or to avoid trouble with the leaked sound. You may make it display on the display part 11 how much distance should be left | separated.

(Ambient sound monitor)
You may make it monitor a user's surrounding sound with a leak sound. FIG. 19 is a diagram illustrating a configuration example of a music reproducing device according to the fifth embodiment. FIG. 20 is a diagram showing an outline of the function of the signal processing unit 15 in FIG. 19, the music reproducing apparatus according to the present embodiment has a configuration in which a level control unit 84 and mixers 85a and 85b are added to the apparatus shown in FIG. The measurement unit 30 acquires signals input by the microphones 22L and 22R, that is, ambient sound signals (hereinafter referred to as ambient sound signals), and inputs the signals to the level control unit 84 via the bus 18. The level controller 84 outputs a signal D1 corresponding to the ambient sound signal and inputs it to the mixers 85a and 85b. When the volume of the music playback device changes, the level control unit 84 attenuates or amplifies the signal D1 and controls the level of the signal D1 according to the change. The mixers 85a and 85b are provided corresponding to the convolution processing units 44a and 44b. The mixers 85a and 85b control the level by adding the output of the level control unit 84 to the output signals of the corresponding convolution processing units 44a and 44b.

  When the user's ambient sound is monitored, when the user changes the volume of the music playback device, the playback volume of the ambient sound also changes. This makes it impossible to accurately monitor the ambient sounds heard by a third party. Therefore, in this embodiment, when the user changes the volume of the music playback device, the level control unit 84 controls the level of the signal D1 corresponding to the ambient sound signal according to the changed amount. That is, when the user increases the volume, the level control unit 84 decreases the level of the signal D1 corresponding to the ambient sound signal, and when the user decreases the volume, the level control unit 84 decreases the level of the signal D1 corresponding to the ambient sound signal. increase. The signal D1 corresponding to the ambient sound signal whose level is controlled in this way is added to the output signals of the convolution processing units 44a and 44b by the mixers 85a and 85b.

  FIG. 21 is a flowchart showing the operation of the music reproducing device shown in FIGS. 19 and 20. In FIG. 21, the processing from step S701 to step S703 is the same as the processing from step S501 to step S503 in FIG.

  In step S704, the signal processing unit 15 determines whether to monitor ambient sound. When the ambient sound is monitored (Yes in step S704), the process proceeds to step S705, and the signal processing unit 15 acquires the amplification factor αp of the amplification unit 16 that is a headphone amplifier. In step S706, the signal processing unit 15 multiplies the microphone input signal by (αhp / αp). By this processing, a signal D1 is obtained.

  In step S707, the signal B1 and the signal D1 are added. In step S708, the added signal B1 and signal D1 are reproduced. In step S709, when there is a request to stop reproduction (Yes in step S709), the signal processing unit 15 stops reproduction, and the process ends. In step S709, when there is no request to stop reproduction (No in step S709), the process returns to step S708, and the signal processing unit 15 continues reproduction.

  If sound leakage monitoring is not performed in step S701 (No in step S701), the process proceeds to step S205, and the normal playback mode is set. The subsequent processing is the same as the processing in steps S205 to S207 described with reference to FIG. In step S701, sound leakage monitoring may be performed when the ambient sound has changed, as in step S301.

  If the ambient sound is not monitored in step S704 (No in step S704), the process proceeds to step S710. In step S710, the signal B1 to which the signal D1 is not added is reproduced. In step S711, when there is a request to stop reproduction (Yes in step S711), the signal processing unit 15 stops reproduction, and the process ends. In step S711, if there is no request to stop the reproduction (No in step S711), the process returns to step S710, and the signal processing unit 15 continues the reproduction.

(Modification 1)
FIG. 22 is a diagram illustrating a first modification of the music reproducing device. When the music reproducing device 10 a performs monaural reproduction instead of stereo reproduction, the headphones 20 a include, for example, a single sound output unit 21, a single microphone 22, and a switch 23.

  The music reproducing device 10a of this example includes the amplifying unit 16L and the amplifying unit 16R, the amplifying unit 17L, and the amplifying unit 17R for two channels shown in FIG. .

  Also in the music playback device 10a of the modification shown in FIG. 22, by playing back the music processed based on the characteristic A1, the user of the headphone 20a confirms sound leakage from the headphone 20a while wearing the headphone 20a. can do.

(Modification 2)
Each unit of the music playback device 10 shown in FIG. 2 may be incorporated in headphones worn by the user on the head. Even in such a case, by reproducing the music processed based on the characteristic A1, the user of the headphones can confirm sound leakage from the headphones while wearing the headphones.

(Modification 3)
A part of the function of the music reproducing device shown in FIG. 2 may be realized by another device. FIG. 23 is a diagram showing a case where a part of the music playback device 10 shown in FIG. 2 is realized by a smart phone 100. Each process described above is realized by installing an application program in the smart phone 100 and executing it.

(Modification 4)
In the above, the stereo headphone 20 has been described with reference to FIG. 3, but a stereo earphone may be used. Also, a monaural headphone or a monaural earphone may be used.

  As long as a microphone can be provided in the housing of the headphone, any of an on-ear type that is hooked on the auricle, an open air type that is placed on the auricle, a sealed type that covers the auricle, and a canal type that is inserted into the ear canal may be used.

  The headphones 20 may have a noise canceling function. Since the headphones having a noise canceling function include a microphone for picking up ambient noise, the microphone can be used as a microphone for acquiring the characteristic A1. This eliminates the need to add a new microphone to the headphones. Further, when measuring the characteristic A1, the noise canceling function may be turned off, or the characteristic A1 may be measured with the noise canceling function turned on.

(Modification 5)
Instead of adjusting the volume of the entire music data, a volume adjusting unit for adjusting a specific frequency portion in the range of the music data may be added. For example, if there is a tendency for the high frequency portion of the music to leak, a volume adjustment unit that adjusts the volume of only that frequency portion may be added.

(Other variations)
The display unit 11 may display a graphic equalizer indicating the level adjustment amount for each frequency region. Then, a volume adjustment unit for the high frequency region may be provided so that the volume can be adjusted only in the high frequency region.

  If the user who has confirmed the sound leakage in the sound leakage monitor mode sets the playback volume so that it can be raised up to here, the volume is memorized, and if the volume is exceeded during playback, a warning sound You may make it notify a user with a message.

  The speaker unit can also function as a microphone if the connection is changed. Therefore, in a stereo type headphone, if a sound is output from one of the two sound output units and the other functions as a microphone, there is no need to provide a microphone in the headphone. A vibration sensor may be provided, and when a vibration peculiar to a railway vehicle is detected, it may be determined that the user is on the train and the operation mode may be set to the sound leakage monitor mode.

(Summary)
According to the above-described music reproducing device, in the sound leakage monitor mode, the listening user can confirm the sound leakage condition, and thus the user can appropriately set the volume. Therefore, when the user himself / herself listens to the same sound as the actual sound leakage, it is possible to adjust the volume appropriately according to the environment and the usage situation. For example, sound that leaks in a train may be masked by low-frequency sound due to running noise, etc., so if the user hears it and the high-frequency sound does not matter, the problem is that the volume remains as it is. It can be judged that there is no. Further, for example, since the inside of the library is quiet, it can be determined that the volume should be lowered for the entire frequency domain.

(Music playback method)
The following music playback method is realized by the music playback device. That is, a step of generating a measurement signal for measuring the spatial characteristics, and a sound corresponding to the measurement signal is output from the sound output unit while the sound output unit is worn by the user, and is transmitted through the surrounding space. A music reproducing method is provided that includes a step of obtaining a first characteristic, which is a spatial characteristic to be obtained, and a reproducing unit step of reproducing a musical piece processed based on the first characteristic. According to this music reproducing method, the user can confirm sound leakage in the state where the headphones are worn while wearing the headphones.

(Music playback program)
In the music reproducing apparatus, a computer generates a signal corresponding to the measurement signal from the sound output unit in a state where the user wears a signal generation unit that generates a measurement signal for measuring spatial characteristics and a sound output unit. A music reproduction program for functioning as a characteristic acquisition unit that outputs and obtains a first characteristic that is a spatial characteristic obtained through the surrounding space, and a reproduction unit that reproduces music processed based on the first characteristic It may be realized by using. If this music reproduction program is used, the user can confirm sound leakage in the state where the headphones are worn while wearing the headphones.

10, 10a Music player 11 Display unit 12 Input unit 13 Control unit 14 Storage unit 15 Signal processing unit 16, 16L, 16R, 17, 17L, 17R Amplifying unit 18 Bus 20, 20a Headphones 21, 21L, 21R Sound output unit 22 , 22L, 22R Microphones 23, 42a, 42b, 45 Switch 30 Measurement unit 31 Signal generation unit 32 Characteristic acquisition unit 40 Playback unit 41 Mode control unit 43a, 43b Playback processing unit 44a, 44b Convolution processing unit 50 Characteristic storage unit 61L, 61R D / A converter 71L, 71R A / D converter 80 Mode storage 81 Inverse filter calculator 82 Noise level calculator 83a, 83b Attenuator 84 Level controller 85a, 85b Mixer 100 Smartphone

Claims (8)

A signal generation unit that generates a measurement signal for measuring a spatial characteristic, a characteristic acquisition unit that acquires a spatial characteristic obtained by outputting a sound corresponding to the measurement signal from a sound output unit, and the characteristic acquisition unit A playback unit that plays back the music processed based on the spatial characteristics
The characteristic acquisition unit is a first characteristic which is a spatial characteristic obtained through a surrounding space by outputting a sound corresponding to the measurement signal from the sound output unit while the sound output unit is worn by a user. Get
The playback unit is a music playback device for playing back music processed based on the first characteristic. The sound output unit is provided in a headphone worn by a user,
The headphone includes a microphone that obtains the sound output from the sound output unit via a space outside the headphone,
The music reproducing device according to claim 1, wherein the characteristic acquisition unit acquires the first characteristic from sound acquired by the microphone in a state where the user wears the headphones. The music reproducing apparatus according to claim 1, wherein the reproduction unit performs a convolution process between music data to be reproduced and the first characteristic.   The image processing apparatus further includes an inverse filter calculation unit that calculates an external auditory canal correction characteristic based on a result measured for the user's ear, and the reproduction unit further performs the convolution process with the first characteristic, and then further performs the external ear canal correction characteristic. The music reproducing device according to claim 3, wherein convolution processing is performed based on the music. A distance input unit for inputting distance data indicating a distance to a position away from the own device;
An attenuation unit that attenuates the level of the music according to the distance data input by the distance input unit;
The music playback device according to claim 1, wherein the playback unit plays back a music whose level is changed by the attenuation unit. An ambient sound acquisition unit for acquiring ambient sounds;
A level control unit that changes the level of the ambient sound acquired by the ambient sound acquisition unit in response to an instruction to change the playback level by the playback unit;
The said reproduction | regeneration part reproduces | regenerates the sound which added the ambient sound which changed the level by the said level control part to the music processed based on the said 1st characteristic. Music playback device. Generating a measurement signal for measuring spatial characteristics;
Obtaining a first characteristic which is a spatial characteristic obtained through the surrounding space by outputting a sound corresponding to the measurement signal from the sound output part in a state where the user is wearing the sound output part;
A playback unit step of playing back the music processed based on the first characteristic;
A music reproduction method comprising: Computer
A signal generator for generating a measurement signal for measuring spatial characteristics;
A characteristic acquisition unit that outputs a sound corresponding to the measurement signal from the sound output unit in a state in which the user is wearing the sound output unit and acquires a first characteristic that is a spatial characteristic obtained through the surrounding space;
A playback unit for playing back the music processed based on the first characteristic;
Music playback program to function as.

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