Earphone and earphone control method

Abstract

This earphone is worn by a user and comprises: a sound pickup unit; a detection unit for detecting movement by the user or the impact of the surrounding environment; and a control unit that performs processing of output sound on the basis of a sound pickup signal picked up by the sound pickup unit and the detection result from the detection unit. For example, not only ambient sound but also noise signals such as breathing sounds, vocal sound, and pulse sounds from the user are adaptively reduced, or ambient sound is introduced into an audio signal. Alternatively, wind noise included in a voice signal or a music signal is adaptively reduced. Alternatively, the characteristics of user voice audio for transmission to be transmitted to a conversation partner terminal are adaptively adjusted, and wind noise included in the user voice audio is reduced.

Description

[Technical Field]

[0001] The present disclosure relates to an earphone and an earphone control method. [Background technology]

[0002] In recent years, headphones have appeared that are not only used to listen to music played from a portable player, but also equipped with a microphone for picking up the user's speech to be transmitted to the other party via a communication terminal such as a smartphone. In other words, as a transmitting / receiving device, headphones in recent years have been commercialized that not only have a driver function for simply outputting sound, but also a microphone function for inputting speech.

[0003] Patent Document 1 discloses an audio headset equipped with a movement sensor that compensates for a decrease in air pressure due to increased or decreased pressure in the acoustic cavity of the headphones caused by the walking movement of the wearer, thereby avoiding a decrease in saturation of the signal detected by the movement sensor during movement and reducing noise. This audio headset discloses headphones that analyze a signal picked up by an internal microphone placed inside the acoustic cavity and a signal sent by the movement sensor to verify whether they satisfy certain predetermined standards, and selectively switch an anti-saturation filter depending on the verification results.

[0004] Patent Document 2 discloses headphones that include a first microphone that picks up ambient sounds outside the user's ear canal, a second microphone that picks up sounds inside the ear canal, and a driver that emits sound toward the ear canal. These headphones determine whether wind noise is occurring by comparing a first signal based on sound picked up by the first microphone with a second signal based on sound picked up by the second microphone. If it is determined that no wind noise is occurring, the headphones add an input signal (for example, a signal played by an external device) to the first signal and output the result toward the driver. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2015-219527 [Patent Document 2] International Publication No. 2018 / 163423 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure provides an earphone and an earphone control method that can generate an output sound that is optimal for the user of the earphone or the other party on the other end of a call, based on a sound signal collected by a sound collection unit and a detection result by a detection unit.

[0007] Furthermore, the present disclosure provides earphones and an earphone control method that can adaptively reduce noise signals such as breathing sounds, the user's voice, and pulse sounds emitted from within the user's body as well as ambient sounds depending on the user's physical movement or speaking state, or that can incorporate ambient sounds into audio signals.

[0008] Furthermore, the present disclosure provides earphones and an earphone control method that can adaptively reduce wind noise contained in an audio signal or music signal depending on the wind conditions around the user and the operating mode specified by the user.

[0009] Furthermore, the present disclosure provides earphones and an earphone control method that can adaptively adjust the characteristics of the user's voice to be transmitted to the other party's terminal in accordance with the state of wind noise that may occur during a call with the other party, thereby reducing the wind noise contained in the user's voice. [Means for solving the problem]

[0010] The present disclosure provides an earphone worn by a user, comprising: a first microphone for picking up ambient sounds of the user; A sound pickup unit and A second sound collection unit disposed in an acoustic space including the user's pinna; The user's movements Bone conduction sensor for detecting vibrations based on and, a sound output unit that outputs a music signal from the user's terminal;a control unit that processes the output sound; the control unit further comprises a periodic sound determination unit that determines whether a periodic sound is being generated based on a detection result of vibration by the bone conduction sensor, an ambient sound addition unit that adds the ambient sound collected by the first sound collection unit to a music signal from the terminal, and a noise reduction unit that reduces noise included in the music signal from the terminal based on a signal collected by the second sound collection unit that has received a portion of the music signal output from the sound emission unit; and when the determination result of the periodic sound determination unit is that the periodic sound is not being generated, the control unit sets the operation of the ambient sound addition unit to ON when the level of the vibration detected by the bone conduction sensor is equal to or greater than a first predetermined value, and sets the operation of the ambient sound addition unit to OFF when the level of the vibration is less than the first predetermined value; and when the determination result of the periodic sound determination unit is that the periodic sound is being generated, sets the operation of the noise reduction unit to ON when the level of the vibration detected by the bone conduction sensor is equal to or greater than a predetermined value. We provide earphones that can be used in various situations.

[0015] The present disclosure also provides an earphone control method for earphones that are worn by a user and can output a music signal from a terminal of the user, the method comprising the steps of: collecting ambient sounds of the user by a first sound collection unit provided in the earphone; and detecting vibrations based on the movement of the user by a bone conduction sensor provided in the earphone; outputting a music signal from the user's terminal by a sound output unit of the earphone; and processing output sounds by a control unit provided in the earphones, wherein the control unit determines whether or not periodic sounds are occurring based on vibration detection results by the bone conduction sensor, and adds the ambient sound collected by the first sound collection unit to the music signal from the terminal, and a second sound collection unit provided in the earphones and placed in an acoustic space including the user's pinna reduces noise contained in the music signal from the terminal based on a signal collected by a portion of the music signal output from the sound emission unit that has been deflected and is being collected, and when the control unit determines that the periodic sounds are not occurring, it sets the ambient sound addition operation to ON when the level of the vibration detected by the bone conduction sensor is equal to or greater than a first predetermined value, and sets the ambient sound addition operation to OFF when the level of the vibration is less than the first predetermined value, and when it determines that the periodic sounds are occurring, it sets the noise reduction operation to ON when the level of the vibration detected by the bone conduction sensor is equal to or greater than a predetermined value. [Effects of the Invention]

[0021] Furthermore, according to the present disclosure, it is possible to adaptively reduce not only ambient sounds but also noise signals such as breathing sounds, the user's voice, and pulse sounds emitted from within the user's body, or to incorporate ambient sounds into audio signals, depending on the user's physical movement or speaking state.

[0022] Furthermore, according to the present disclosure, wind noise contained in an audio signal or music signal can be adaptively reduced according to the wind conditions around the user and the operation mode designated by the user.

[0023] Furthermore, according to the present disclosure, the characteristics of the user voice to be transmitted to the other party's terminal can be adaptively adjusted according to the state of wind noise that may occur during a call with the other party, thereby reducing the wind noise contained in the user voice. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a side view illustrating a state in which the headphones according to the first embodiment are worn on a user's head. [Figure 2] FIG. 2 is a cross-sectional view illustrating a schematic example of the internal hardware configuration of the headphones shown in FIG. 1. [Figure 3] A hardware block diagram illustrating the processing on the circuit board shown in FIG. [Figure 4] FIG. 3 is a schematic diagram illustrating a first method of active noise control in the headphones shown in FIG. [Figure 5] FIG. 4 is a schematic diagram illustrating a second method of active noise control that is different from the first method shown in FIG. [Figure 6] 4 is a flowchart illustrating a processing flow on the circuit board shown in FIG. 3. [Figure 7] 10 is a hardware block diagram illustrating processing on a circuit board according to a second embodiment. [Figure 8] 8 is a flowchart illustrating a processing flow on the circuit board shown in FIG. 7. [Figure 9] 10 is a hardware block diagram illustrating processing on a circuit board according to a third embodiment. [Figure 10] 10 is a flowchart illustrating a processing flow on the circuit board shown in FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, with reference to the accompanying drawings as appropriate, detailed descriptions of embodiments specifically disclosing earphones and earphone control methods according to the present disclosure will be provided. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Furthermore, each of the accompanying drawings will be referenced according to the direction of the reference numerals. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0026] For example, in this disclosure, overhead headphones worn on the user's head are described as an example of the present disclosure, but the present disclosure is not limited to these and may also be applied to in-ear earphones. That is, the present disclosure can also be applied to earphones that do not have a main body or ear pads as a casing that surrounds or covers the ear. Furthermore, the present disclosure is not limited to embodiments such as headphones or earphones, and can be applied as appropriate to any device used as an earphone, as long as it has a driver, a microphone, etc.

[0027] Furthermore, the terms "unit" and "device" used in the embodiments are not limited to physical components that are mechanically realized by hardware, but also include components whose functions are realized by software such as programs. Furthermore, the functions of one component may be realized by two or more physical components, or the functions of two or more components may be realized by, for example, one physical component.

[0028] (Embodiment 1) A first embodiment according to the present disclosure will be described with reference to FIGS.

[0029] [Background to the first embodiment] First, the circumstances leading to this embodiment will be described.

[0030] The configuration disclosed in WO 2018 / 163423 makes it possible to reduce wind noise when it occurs while listening to music playback. However, the configuration disclosed in WO 2018 / 163423 does not anticipate wind noise being generated while a user wearing headphones is talking to a call partner. Therefore, when wind noise occurs while a user is talking to a call partner, it is difficult to reduce the wind noise contained in the user's speech (in other words, the audio signal for transmission to the call partner), leaving room for improvement.

[0031] In contrast, in this embodiment, the characteristics of the user voice to be transmitted to the other party's terminal (such as a smartphone) are adaptively adjusted according to the state of wind noise that may occur during a call with the other party, thereby making it possible to reduce the wind noise contained in the user voice.

[0032] [Headphone hardware configuration] The hardware configuration of headphones 1 (an example of earphones) according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a side view illustrating a state in which headphones 1 according to this embodiment are worn on the head of a user U. Figure 2 is a cross-sectional view that schematically illustrates an example of the internal hardware configuration of headphones 1 shown in Figure 1.

[0033] 1 and 2, headphones 1 according to this embodiment are, for example, an overhead type, and include a headband 2 and a pair of main units 3 disposed at both ends of the headband 2. In this embodiment, headphones 1 also include a wireless communication unit (not shown) capable of communicating according to the Bluetooth (registered trademark) communication standard, and are wirelessly connected to a sound source device such as a radio or music player for music playback, or to a telephone device such as a smartphone P1 (see FIG. 3) of a user U for telephone use. Headphones 1 receive audio signals, music signals, control signals, and the like transmitted from these devices, and output the audio signals as sound waves, or pick up the speech of user U and transmit the collected audio results to these devices.

[0034] In the present embodiment, smartphones P1 and P2 are used as an example of a device with which the headphones 1 communicate wirelessly, but the present invention is not limited to this and various devices can be connected as long as they are capable of wireless communication. In the following description, the term "audio signal" also includes the concept of a music signal unless otherwise specified.

[0035] The headband 2 is made of a long member, curved in a substantially arc shape, and provided elastically. The headband 2 sandwiches the head of the user U from both the left and right sides when the headphones 1 are worn by the user U. This allows the headband 2 to press the pair of main bodies 3 against the left and right sides of the user U's head due to its elasticity, making it possible to securely wear the headphones 1 on the user U's head.

[0036] In addition, the headband 2 of this embodiment may be provided with a pair of expansion and contraction mechanisms, and the length of the headband 2 may be adjusted according to the size of the user U's head by expanding and contracting each of the pair of expansion and contraction mechanisms.

[0037] Each of the pair of main bodies 3 is a member that comes into contact with the ear of a user U wearing the headphones 1, and is formed in a dome or egg shape. When the headphones 1 are worn on the head of the user U, the pair of main bodies 3 are positioned so as to cover the ears of the user U, and this positioned state is the normal use state of the headphones 1. Each of the pair of main bodies 3 is configured to include a housing 4, a partition plate 6, and ear pads 7 as structural members.

[0038] The housing 4 is formed in a dome shape that forms the outer shell of the main body 3 and has an opening 5. The housing 4 is attached to the headband 2 so that the openings 5 ​​are positioned opposite each other across the head of the user U when the headphones 1 are worn by the user U.

[0039] The partition plate 6 is a plate-like member that forms the inner hull of the main body 3 and is arranged to close the opening 5 of the housing 4. A through-hole is formed in the center of the partition plate 6, and a driver 10 (described later) is inserted into and fixed in this through-hole. The housing 4 and the partition plate 6 define a storage space 12.

[0040] The ear pads 7 are formed in an annular shape and encircle the sides of the ears of a user U wearing the headphones 1. The ear pads 7 are arranged extending in the circumferential direction around the periphery of the opening 5 of the housing 4. The ear pads 7 are made of a soft resin material and are provided so that they can deform according to the shape around the ears of the user U. This deformation improves the fit between the ear pads 7 and the periphery of the ears of the user U. An acoustic space 11 is defined by the ear pads 7 and the partition plate 6. When the headphones 1 are worn by the user U, the acoustic space 11 becomes a sealed space that includes the user U's auricle at the contact area of ​​the ear pads 7.

[0041] In the acoustic space 11, the ear pads 7 physically prevent sound from leaking outside the headphones 1 and prevent ambient sound from entering the headphones 1.

[0042] In addition, each of the pair of main body parts 3 is configured to include, as electrical and electronic components, a driver 10, multiple microphones (an example of a sound collection part), a bone conduction sensor 9 (an example of a vibration detection part, which is an example of a detection part), and a circuit board 20 (an example of a signal processing part).

[0043] The driver 10 outputs a signal such as an audio signal or a music signal. Specifically, the driver 10 has a diaphragm (not shown) and converts the audio signal into a sound wave (air vibration) by vibrating the diaphragm based on the audio signal input to the driver 10. The sound wave output from the driver 10 propagates to the eardrum of the user U.

[0044] The multiple microphones include at least three types: an internal microphone 8A (an example of a wraparound sound collection unit), an external microphone 8B, and a speaking microphone 8C. In this embodiment, as will be described later, the external microphone 8B and the speaking microphone operate as sound collection devices that collect sounds around the user U.

[0045] The internal microphone 8A is disposed inside an acoustic space 11 partitioned by the ear pads 7 and the partition plate 6, with its detection portion (not shown) facing the acoustic space 11. The internal microphone 8A is also disposed inside the acoustic space 11 as close as possible to the ear canal of the ear of the user U. As a result, the internal microphone 8A picks up sounds that are physically generated inside the acoustic space 11, including sound waves output from the driver 10.

[0046] That is, internal microphone 8A is provided so as to be able to collect noise that enters acoustic space 11 through housing 4, ear pads 7, etc. as a wraparound sound signal together with the audio signal or music signal output from driver 10. Internal microphone 8A is also electrically connected to circuit board 20 (see FIG. 3) by a signal line.

[0047] The external microphone 8B and the speaking microphone are stored in a storage space 12 partitioned by the housing 4 and the partition plate 6. The housing 4 has a plurality of through-holes (not shown), and the external microphone 8B and the speaking microphone 8C are attached to the housing 4 so as to be able to pick up sounds outside the headphones 1 through these through-holes.

[0048] The external microphone 8B is positioned so that it can pick up ambient noise (for example, wind noise) outside the headphones 1. The speech microphone 8C is positioned so that it can pick up speech from the user U wearing the headphones 1, and so-called hands-free calling is realized together with the driver 10 in a state where the headphones 1 can communicate with a mobile phone device such as a smartphone P1.

[0049] The bone conduction sensor 9 includes a piezoelectric element (not shown) and converts vibrations (bone conduction vibrations) transmitted to the bones of the user U into an electrical signal. The bone conduction sensor 9 is attached to the headphones 1 so as to be able to come into contact with the surface of the face around the ear or the back of the auricle. In the acoustic space 11, the bone conduction sensor 9 is placed at a distance from the driver 10. As the voice spoken by the user U is conducted to the bones of the face and head, the bone vibrations are detected and the detection result is converted into an electrical signal and output. This electrical signal makes it possible to detect whether the user U is speaking. The bone conduction sensor 9 is electrically connected to a circuit board 20 (see FIG. 3) by a signal line.

[0050] The circuit board 20 (see FIG. 3) is formed in a flat plate shape, and has a plurality of circuits arranged on its surface. That is, the circuit board 20 has a central processing circuit (not shown), a read-only memory circuit (not shown), a writeable memory circuit (not shown), and the like, and operates as a control board for the headphones 1 that performs appropriate signal processing.

[0051] [Circuit board configuration] Next, the configuration of the circuit board 20 will be described with reference to Fig. 3. Fig. 3 is a hardware block diagram illustrating the processing on the circuit board 20 shown in Fig. 2.

[0052] As described above, circuit board 20 is configured as a general-purpose control board, and a program (not shown) serving as software stored and held in a storage device (not shown) provided on the control board is executed by a processing unit (not shown) such as a central processing circuit. In this embodiment, circuit board 20 also has a plurality of integrated circuits mounted thereon as hardware physically mounted thereon, each of which specializes in performing predetermined processing. In other words, each block shown inside circuit board 20 in FIG. 3 represents a function realized by software such as a program, or a function realized by hardware such as a dedicated integrated circuit.

[0053] In addition, although the functions realized by the circuit board 20 are described as being realized by both software and hardware in this embodiment, this is not limiting. For example, all of the functions may be realized by hardware as the physical configuration of the "device."

[0054] Furthermore, as described above, the circuit board 20 is equipped with a wireless communication unit (not shown), and in this embodiment, the circuit board 20 is wirelessly connected to the smartphone P1 owned by the user U via the wireless communication unit. The user U of the headphones 1 and the other smartphone P2, including the other party of the call, are both connected to a mobile phone network 13, and the user U can make a call to the other party of the call, that is, make or send a call, via the mobile phone network 13 (see FIG. 3). When making or sending a call, the user U can perform a so-called hands-free call by using the headphones 1 of this embodiment. When making a hands-free call, the audio signal of the call being made or sent is exchanged between the smartphone P1 of the user U and the headphones 1 via wireless communication.

[0055] In this embodiment, the wireless communication unit of the headphones 1 communicates in accordance with the Bluetooth (registered trademark) communication standard, but is not limited thereto and may be provided so as to be connectable to a communication line such as Wi-Fi (registered trademark) or a mobile communication line. The mobile phone network 13 includes at least a wired or wireless line that enables communication between telephone devices such as the smartphone P1, and may be configured to include part or all of an Internet line. The mobile phone network 13 may also be configured to include a local area network (LAN), a wide area network (WAN), and other types of networks that are interconnected and used to facilitate communication between telephone devices.

[0056] In addition, in this embodiment, a case where the headphones 1 are used for telephone purposes is described as one example, and as will be described later, the ambient filter / volume adjustment unit 44, the feedforward filter unit 45, and the second digital adder 46B do not operate in the ANC circuit 40 (see dotted lines).

[0057] 3, at least a main circuit 30 (an example of a signal processing unit), an ANC circuit 40 (an example of a signal processing unit), and a detection circuit 50 (an example of a signal processing unit that is an example of a control unit or an example of a periodic sound determination unit that is an example of a control unit) are mounted on the circuit board 20. The main circuit 30, the detection circuit 50, and the ANC circuit 40 mutually control each other in a coordinated manner by transmitting and receiving control signals to and from each other, and also exchange audio signals as PCM (Pulse Code Modulation) digital signals.

[0058] The main circuit 30 includes a bandpass filter and volume adjustment unit 31 (an example of a signal processing unit), a music playback and telephone mode switching unit 32 (an example of an input unit), and a volume adjustment unit 33.

[0059] The bandpass filter and volume adjustment unit 31 receives control signals representing the detection results of the speech detection unit 51 (see below) and the wind noise detection unit 52 (see below) of the detection circuit 50, and also receives an audio signal transmitted as a digital signal from a beam forming unit 53 (see below) of the detection circuit 50. Based on the control signal from this detection circuit 50, the bandpass filter and volume adjustment unit 31 passes audio components of a predetermined frequency band from the received audio signal, and adjusts the volume level of the passed audio signal (for example, an audio signal based on the speech of the user U or an audio signal of ambient sound).

[0060] That is, the bandpass filter and volume adjustment unit 31 adjusts the characteristics of the audio signal based on the speech of the user U, based on the presence or absence of speech by the user U and the detection results of wind noise. This adjusted audio signal is wirelessly transmitted as a speech transmission signal to the smartphone P1 of the user U via the wireless communication unit of the circuit board 20. Note that the bandpass filter and volume adjustment unit 31 is set up to operate only when the headphones 1 are used for telephone calls.

[0061] The music playback / telephone mode switching unit 32 is wirelessly connected to the smartphone P1 of the user U via wireless communication via the circuit board 20, and receives audio signals transmitted from the smartphone P1. That is, the music playback / telephone mode switching unit 32 is configured to be able to input audio signals or music signals for playback from the smartphone P2 of the other party. Based on the received audio signals or control signals transmitted from the smartphone P1, the music playback / telephone mode switching unit 32 determines whether the operating mode (use) of the headphones 1 is for music playback or for telephone use, and manages the input.

[0062] For example, in this embodiment, the music playback / telephone mode switching unit 32 receives an audio signal transmitted from the other party of the user U as a call signal, and determines that the headphones are being used for telephone calls based on the reception result. The music playback / telephone mode switching unit 32 then switches the operation mode of the headphones 1 to telephone use, and transmits the audio signal input thereto to the volume adjustment unit 33. The volume adjustment unit 33 adjusts the volume level of the transmitted audio signal and transmits it to a first digital adder 46A (described later) of the ANC circuit 40.

[0063] The ANC circuit 40 includes a first amplifier section 41A, a second amplifier section 41B, a third amplifier section 41C, a fourth amplifier section 41D, a first analog-to-digital conversion section 42A, a second analog-to-digital conversion section 42B, a sidetone filter section 43, an ambient filter / volume adjustment section 44, a feedforward filter section 45, a first digital adder section 46A, a second digital adder section 46B, a digital-to-analog conversion section 47, a feedback filter section 48, and an analog adder section 49.

[0064] The first amplifier section 41A is electrically connected to the external microphone 8B, amplifies the audio signal output from the external microphone 8B, and outputs the amplified audio signal to the first analog-to-digital converter section 42A.

[0065] Each of the second amplifier sections 41B is electrically connected to a microphone 8C for speech, and amplifies the audio signal output from the microphone 8C for speech, and outputs the amplified audio signal to the first analog-to-digital conversion section 42A.

[0066] First analog-to-digital conversion unit 42A converts two-channel analog signals from speaking microphone 8C or external microphone 8B into digital signals, and transmits these two-channel digital signals to sidetone filter unit 43, ambient filter / volume adjustment unit 44, feedforward filter unit 45, and beamformer 53 (described later) of detection circuit 50.

[0067] The second analog-to-digital conversion unit 42B is electrically connected to the bone conduction sensor 9 and converts the electrical signal output from the bone conduction sensor 9 into a digital signal. The second analog-to-digital conversion unit 42B transmits this digital signal to an utterance detection unit 51 (described later) of the detection circuit 50.

[0068] The sidetone filter unit 43 receives two-channel digital audio signals transmitted from the first analog-to-digital converter 42 A. These digital audio signals are based on the external microphone 8 B and the speaking microphone 8 C, and the sidetone filter unit 43 transmits these digital audio signals to the first digital adder 46 A.

[0069] That is, when the headphones 1 are used for telephone purposes, the external microphone 8B and the speech microphone 8C pick up the speech of the user U. Therefore, the operation of the sidetone filter unit 43 results in a part of the speech of the user U being looped back (added) to the audio signal that is output to the driver 10. This allows the user U to hear their own speech through the headphones 1, making it easier for them to speak when using the headphones 1 for telephone purposes. Note that the sidetone filter unit 43 is designed to operate only when the headphones 1 are used for telephone purposes.

[0070] Similarly, the ambient filter and volume adjustment unit 44 receives the two-channel audio digital signals output from the first analog-to-digital conversion unit 42 A. The ambient filter and volume adjustment unit 44 mainly extracts low-frequency components from these two-channel audio signals, adjusts the volume levels of the extracted components, and sends them to the first digital addition unit 46 A.

[0071] When the headphones 1 are in normal use, the ear pads 7 and the like prevent the transmission of ambient sounds around the user U into the aforementioned acoustic space 11. Therefore, by operating the ambient filter and volume adjustment unit 44, ambient sounds such as vehicle noise and warning sirens are actively captured via the external microphone 8B and the speaking microphone 8C, and this ambient sound can be electrically passed from the outside world to the ear canal of the user U. This allows the user U to understand the ambient sound situation even when wearing the headphones 1.

[0072] The ambient filter / volume adjustment unit 44 is turned on and off by an operating system or application installed on the smartphone P1, etc., and in this embodiment, the ambient filter / volume adjustment unit 44 is set to off. Therefore, in Figure 3, the block representing the ambient filter / volume adjustment unit 44 and the associated signal lines are shown with dotted lines.

[0073] Similarly, the feedforward filter unit 45 receives the digital audio signals for two channels output from the first analog-to-digital conversion unit 42A. The feedforward filter unit 45 performs filtering mainly on mid-range (mid-frequency) components that contain a large amount of human voice, and transmits the processing result to the second digital addition unit 46B. Note that the feedforward filter unit 45 is also set to off in this embodiment. Therefore, in FIG. 3, the block representing the feedforward filter unit 45 and its associated signal lines are shown with dotted lines.

[0074] The first digital adder 46A adds the digital audio signal transmitted from the side tone filter unit 43 or the ambient filter / volume adjustment unit 44 to the digital audio signal transmitted from the volume adjustment unit 33 of the main circuit 30, and then transmits the result to the second digital adder 46B.

[0075] Second digital adder 46B receives the digital audio signals transmitted from first digital adder 46A and feedforward filter 45, adds these digital signals, and transmits the addition result to digital-to-analog converter 47. In this embodiment, feedforward filter 45 is set to off, so second digital adder 46B does not receive any input from feedforward filter 45 and simply passes (through control) the transmission from first digital adder 46A. For this reason, the block diagram representing second digital adder 46B is shown by a dotted line in FIG. 3.

[0076] The digital-to-analog converter 47 converts the result of the addition into an analog signal, and outputs the converted analog signal to the analog adder 49 .

[0077] The third amplifier section 41C is electrically connected to the internal microphone 8A, amplifies the audio signal (that is, the wraparound sound signal) output from the internal microphone 8A, and outputs the amplified signal to the feedback filter section .

[0078] The feedback filter unit 48 converts the analog signal based on the internal microphone 8A into an inverse phase signal to generate an inverse phase signal, and outputs the inverse phase signal to the analog adder unit 49.

[0079] The analog addition unit 49 adds the audio signal output from the digital-to-analog conversion unit 47 and the audio signal (opposite phase signal) output from the feedback filter unit 48 as an analog signal, and outputs the result to the fourth amplifier unit 41D.

[0080] As described above, internal microphone 8A picks up noise that cannot be completely suppressed by ear pad 7 and that enters acoustic space 11 as wraparound sound along with the audio or music signal output from driver 10. Feedback filter unit 48 converts the picked-up wraparound sound audio signal into an inverse phase to generate an inverse phase signal of the analog signal. Analog adder 49 adds this inverse phase signal to the analog signal just before it is output to driver 10. Adding these analog signals makes it possible to actively remove the aforementioned noise.

[0081] In this way, the feedback filter unit 48 and the analog adder unit 49 reduce the noise contained in the audio signal from the smartphone P1 based on the signal picked up by the internal microphone 8A, which is a portion of the audio signal output from the driver 10.

[0082] The fourth amplifier unit 41D is electrically connected to the driver 10, and amplifies the analog signal output from the analog adder unit 49 and outputs the amplified signal to the driver 10. Based on the input, the driver 10 outputs a signal such as an audio signal or a music signal as physical air vibrations (sound waves).

[0083] Similarly, the on / off operation of the feedback filter unit 48 and the analog adding unit 49 is controlled by an application installed on the smartphone P1 or the like, and can be arbitrarily changed by the user U. When set to off by the user U, a control signal relating to this setting is transmitted to the analog adding unit 49. Based on this control signal, the analog adding unit 49 controls the audio signal from the feedback filter unit 48 so that it is not input to itself.

[0084] The detection circuit 50 includes an utterance detection unit 51, a wind noise detection unit 52, and a beam forming unit 53.

[0085] The speech detection unit 51 is connected to the second analog-digital conversion unit 42B of the ANC circuit 40, and receives a digital signal transmitted from the second analog-digital conversion unit 42B. This digital signal is generated by the bone conduction sensor 9, and the speech detection unit 51 uses this digital signal to detect bone conduction vibrations caused by the user U's speech and determine (detect) whether the user U is speaking. The detection result is transmitted as a control signal to the beam forming unit 53 and the bandpass filter and volume adjustment unit 31 of the main circuit 30. The speech detection unit 51 is configured to operate only when the headphones 1 are used for telephone calls.

[0086] The wind noise detection unit 52 (an example of a detection unit) is directly electrically connected to the external microphone 8B and the speaking microphone 8C, and receives the analog signals before they are amplified by the first amplifier unit 41A and the second amplifier unit 41B. These analog signals are two-channel analog signals based on the external microphone 8B and the speaking microphone 8C, and the wind noise detection unit 52 uses these two-channel analog signals to sense wind noise occurring around the user U and determine (detect) the presence or absence of wind noise. Furthermore, the wind noise detection unit 52 can also detect the level (strength) of wind noise by, for example, reading a threshold value stored in a memory device on the circuit board 20 in advance and determining whether the two-channel digital signals are equal to or greater than a predetermined threshold value.

[0087] Specifically, in this embodiment, wind noise detection unit 52 calculates the correlation between the two channels of ambient sounds picked up by external microphone 8B and speaking microphone 8C, and the intensity level of the ambient sounds. Since ordinary sounds are often correlated with each other, wind noise detection unit 52 determines that wind noise is present if the calculation results in the two channels of ambient sounds being uncorrelated and having a high intensity level. In this way, wind noise detection unit 52 detects the presence or absence of wind noise around user U based on the ambient sounds picked up by external microphone 8B and speaking microphone 8C, and in this embodiment, transmits this detection result to bandpass filter and volume adjustment unit 31 of main circuit 30.

[0088] Like the wind noise detection unit 52, the beam forming unit 53 is connected to the first analog-to-digital conversion unit 42A of the ANC circuit 40 and receives the digital signals transmitted from the first analog-to-digital conversion unit 42A. The beam forming unit 53 performs audio processing on these two-channel digital signals to suppress sounds other than those uttered by the user U. This audio processing allows the beam forming unit 53 to increase the directivity of the sound physically emitted from the user U's mouth and pick it up, thereby enabling the transmission (outgoing speech) of sound that is easy for the other party to hear during so-called hands-free calls. In this way, the beam forming unit 53 transmits the digital signal of the sound, with increased directivity toward the user U's mouth, to the bandpass filter and volume adjustment unit 31. The beam forming unit 53 is configured to operate only when the headphones 1 are used for telephone calls.

[0089] [Outline of active noise control] Next, with reference to Figures 4 and 5, an overview of active noise control performed in the ANC circuit 40 including the feedback filter section 48 will be described by illustrating two exemplary methods. Figure 4 is a schematic diagram illustrating a first method of active noise control in the headphones 1 shown in Figure 2. Figure 5 is a schematic diagram illustrating a second method of active noise control that is different from the first method shown in Figure 3. Note that the first method is ideal, and the second method is actually adopted.

[0090] 4, in the first method, noise (such as wind noise) from the user U's surroundings that could not be completely suppressed physically by the ear pads 7 in the acoustic space 11 is physically added to the sound (original sound) output through the music playback / telephone mode switching unit 32. If left as is, the sound with this noise added will be transmitted through the middle ear of the user U, but the ANC circuit 40 on the circuit board 20 picks up the sound with this noise added with the internal microphone 8A and converts the picked-up sound signal to an inverse phase to generate an inverse phase signal.

[0091] In the first method, both the sound with noise added and the opposite phase signal are physically output and added inside the acoustic space 11 including the middle ear of the user U, and these sounds cancel each other out. As a result, the middle ear of the user U becomes theoretically silent (in a silent state), and in this silent state, the sound (original sound) is output again through the music playback / telephone mode switching unit 32.

[0092] In this way, in the first method, a sound that is identical to or close to the original sound is ideally reproduced with noise actively removed, and is transmitted through the middle ear of the user U.

[0093] However, although this first method is ideal for active noise control, it is difficult to perform as ideally as the first method when actually implementing it in headphones 1. Therefore, in practice, active noise control is realized by the second method described below.

[0094] 5, in the second method, which is a practical method, no silent state is provided, but the sound (original sound) output through the music playback / telephone mode switching unit 32 is amplified and output, and noise from the surrounding sounds of the user U is physically added to this amplified sound. In this case, the ANC circuit 40 of the circuit board 20 converts the sound signal before amplification, i.e., the sound obtained by adding noise to the original sound, into an inverse phase to generate an inverse phase signal, as in the first method described above.

[0095] In the second method, both the amplified sound with noise added and its antiphase signal are physically output and added inside acoustic space 11 that includes the middle ear of user U. Because the noise levels are equal between these sound signals, the noise components are mainly removed, and the original sound components remain.

[0096] In this way, similarly to the second method, a sound that is identical to or close to the original sound is actually reproduced with noise actively removed, and is transmitted through the middle ear of the user U. In this embodiment, the second method described above is applied.

[0097] [Processing flow for circuit boards] Next, a processing flow on the circuit board 20 according to this embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart illustrating a processing flow on the circuit board 20 shown in Fig. 3.

[0098] 6, the music playback / telephone mode switching unit 32 determines whether the operation mode (use) of the audio output of the headphones 1 is for telephone use (S101). If the result of this determination is that the headphones 1 are not for telephone use (NO in S101), the processing flow returns to step S101 again. In other words, the processing flow does not proceed to steps S102 and thereafter unless the operation mode of the headphones 1 is for telephone use.

[0099] On the other hand, if it is determined that the device is being used for telephone calls (YES in S101), wind noise detection unit 52 detects wind noise occurring around user U using two-channel digital signals from external microphone 8B and speaking microphone 8C, and determines whether wind noise is present (S102). If the determination result determines that there is no wind noise (NO in S102), bandpass filter and volume adjustment unit 31 passes audio components in the frequency band from 300 Hz to 8 kHz, but transmits the audio signal without adjusting its volume level (i.e., without increasing or decreasing the volume level, and at the same level) (S110).

[0100] If it is determined that wind noise is present (YES in S102), the wind noise detection unit 52 detects the level of wind noise by determining whether the digital signals for two channels are equal to or greater than a pre-loaded threshold value (S103). In this embodiment, the threshold value is set to -10 dBV.

[0101] If it is determined that the wind noise level is equal to or greater than a predetermined value (-10 dBV) (YES in S103), the speech detection unit 51 determines whether or not the user U is speaking based on the digital signal from the bone conduction sensor 9 (S104). If it is determined that the user U is speaking as a result of this determination (YES in S104), the bandpass filter and volume adjustment unit 31 passes audio components in the frequency band from 1 kHz to 4 kHz out of the audio signal based on the user U's speech. Furthermore, the bandpass filter and volume adjustment unit 31 adjusts the volume level of the passed audio signal by increasing it by +6 dB (S105).

[0102] That is, when the wind noise level is equal to or higher than a predetermined value (-10 dBV) and the user U's speech is detected, the bandpass filter and volume adjustment unit 31 passes audio signals based on the user U's speech in a frequency band from 1 kHz to 4 kHz (an example of a first frequency band) that is higher than the frequency band of the wind noise. The bandpass filter and volume adjustment unit 31 also increases the volume level of the audio signals that have been passed in that frequency band, i.e., the audio signals based on the user U's speech, by +6 dB (an example of a first predetermined value). Therefore, in this embodiment, even when the user U speaks through the headphones 1 in an environment where the wind noise level is relatively high, it is possible to adaptively adjust the characteristics of the user's voice to be transmitted to the smartphone P2 of the other party, thereby reducing the wind noise contained in the user's voice.

[0103] If it is determined that the user U is not speaking (NO in S104), the sounds picked up by the external microphone 8B and the speaking microphone 8C in this case are ambient sounds, and the band-pass filter and volume adjustment unit 31 passes sound components in the frequency band from 2 kHz to 3 kHz. Furthermore, the band-pass filter and volume adjustment unit 31 adjusts the volume level of the passed sound signal by reducing it by 6 dB (i.e., adding -6 dB) (S106).

[0104] That is, when the wind noise level is equal to or higher than a predetermined value (-10 dBV) and no speech by the user U is detected, the bandpass filter / volume adjustment unit 31 passes audio signals in a frequency band from 2 kHz to 3 kHz (an example of a second frequency band), which is higher than the frequency band of the wind noise, among the ambient sound signals. The bandpass filter / volume adjustment unit 31 also adds -6 dB (an example of a second predetermined value) to the volume level of the audio signals that have passed in that frequency band, i.e., the ambient sound signals (i.e., reduces the volume by 6 dB). Therefore, in this embodiment, even when the wind noise level is relatively high and the user U does not speak through the headphones 1, it is possible to adaptively adjust the characteristics of the user voice to be transmitted to the smartphone P2 of the other party, thereby reducing the wind noise contained in the user voice.

[0105] On the other hand, if it is determined that the wind noise level is less than the predetermined value (-10 dBV) (NO in S103), the speech detection unit 51 determines whether or not the user U is speaking (S107). If it is determined that the user U is speaking as a result of this determination (YES in S107), the bandpass filter and volume adjustment unit 31 passes audio components in the frequency band from 700 Hz to 4 kHz out of the audio signal based on the user U's speech. Furthermore, the bandpass filter and volume adjustment unit 31 adjusts the volume level of the passed audio signal by increasing it by +3 dB (S108).

[0106] That is, when the wind noise level is below a predetermined value (-10 dBV) and the user U's speech is detected, the bandpass filter and volume adjustment unit 31 passes audio signals based on the user U's speech in a frequency band from 700 kHz to 4 kHz (an example of a third frequency band), which is higher than the frequency band of the wind noise. The bandpass filter and volume adjustment unit 31 also increases the volume level of the audio signals passed in that frequency band, i.e., the audio signals based on the user U's speech, by +3 dB (an example of a third predetermined value). Therefore, in this embodiment, even when the user U speaks through the headphones 1 with a relatively low wind noise level, it is possible to adaptively adjust the characteristics of the user's voice to be transmitted to the smartphone P2 of the other party, thereby reducing the wind noise contained in the user's voice.

[0107] If it is determined that the user U is not speaking (NO in S107), the band-pass filter and volume adjustment unit 31 of the circuit board 20 passes audio components in the frequency band from 1 kHz to 3 kHz. Furthermore, the band-pass filter and volume adjustment unit 31 adjusts the volume level of the passed audio signal by reducing it by 3 dB (i.e., adding -3 dB) (S109).

[0108] That is, when the wind noise level is below a predetermined value (-10 dBV) and no speech by the user U is detected, the bandpass filter and volume adjustment unit 31 of the circuit board 20 passes audio signals of the ambient sound in a frequency band from 1 kHz to 3 kHz (an example of a fourth frequency band), which is higher than the frequency band of the wind noise. The bandpass filter and volume adjustment unit 31 of the circuit board 20 also adds -3 dB (an example of a fourth predetermined value) to the volume level of the audio signals that have passed in that frequency band, i.e., the ambient sound signals (i.e., reduces the volume by 3 dB). Therefore, in this embodiment, even when the wind noise level is relatively low and the user U does not speak through the headphones 1, it is possible to adaptively adjust the characteristics of the user voice to be transmitted to the smartphone P2 of the other party, thereby reducing the wind noise contained in the user voice.

[0109] In this way, the circuit board 20 detects the presence or absence of wind noise around the user U based on the ambient sounds picked up by the multiple microphones, and then adjusts the characteristics of the audio signal based on the speech of the user U based on the presence or absence of speech by the user U and the detection result of the wind noise. Therefore, in this embodiment, it is possible to adaptively adjust the characteristics of the user voice for speaking to be transmitted to the smartphone P2 of the other party in accordance with the state of wind noise that may occur during a call with the other party, thereby reducing the wind noise contained in the user voice.

[0110] As described above, the headphones 1 (an example of earphones) of embodiment 1 are headphones 1 worn by a user U, and include a plurality of microphones (an example of a sound collection unit) that collect sounds around the user U, a speech detection unit 51 that detects whether or not the user U is speaking, a wind noise detection unit 52 that detects whether or not there is wind noise around the user U based on the sounds around the user U collected by each of the plurality of microphones, and a bandpass filter and volume adjustment unit 31 (an example of a signal processing unit) on a circuit board 20 that adjusts the characteristics of an audio signal based on the user U's speech based on the detection results of whether or not the user U is speaking and the wind noise.

[0111] Furthermore, according to the earphone control method of embodiment 1, the earphone control method is for headphones 1 (an example of earphones) worn by a user U, and includes the steps of collecting ambient sounds around the user U at multiple locations (sound collection process), detecting whether or not the user U is speaking (speech detection process), detecting whether or not there is wind noise around the user U based on the ambient sounds collected in the sound collection process (wind noise detection process), and adjusting the characteristics of the audio signal based on the user U's speech based on whether or not the user U is speaking and the detection results of the wind noise (signal processing process).

[0112] As a result, according to the headphones 1 or earphone control method of embodiment 1, the characteristics of the user voice to be transmitted to the smartphone P2 (an example of a terminal) of the other party of the call can be adaptively adjusted depending on the state of wind noise that may occur during a call with the other party, thereby reducing the wind noise contained in the user voice.

[0113] Furthermore, according to the headphones 1 (an example of earphones) of the first embodiment, when the level of wind noise is equal to or higher than a predetermined value (-10 dBV) and an utterance of the user U is detected, the bandpass filter and volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 passes an audio signal based on the user U's utterance in a frequency band from 1 kHz to 4 kHz (an example of a first frequency band), which is higher than the frequency band of the wind noise. The bandpass filter and volume adjustment unit 31 of the circuit board 20 also increases the volume level of the audio signal based on the user U's utterance by +6 dB (an example of a first predetermined value). Thus, according to the headphones 1 or earphone control method of the first embodiment, even when the user U speaks through the headphones 1 in an environment where the level of wind noise is relatively high, it is possible to adaptively adjust the characteristics of the user's voice to be transmitted to the smartphone P2 (an example of a terminal) of the other party, thereby reducing the wind noise contained in the user's voice.

[0114] Furthermore, according to the headphones 1 (an example of earphones) of the first embodiment, when the level of wind noise is equal to or higher than a predetermined value (-10 dBV) and no speech by the user U is detected, the bandpass filter and volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 passes audio signals of the ambient sound signals in a frequency band from 2 kHz to 3 kHz (an example of a second frequency band), which is higher than the frequency band of the wind noise. The bandpass filter and volume adjustment unit 31 of the circuit board 20 also adds -6 dB to the volume level of the ambient sound signals (i.e., reduces the volume by 6 dB (an example of a second predetermined value)). Thus, according to the headphones 1 or earphone control method of the first embodiment, even when the level of wind noise is relatively high and the user U does not speak through the headphones 1, it is possible to adaptively adjust the characteristics of the user's voice to be transmitted to the smartphone P2 (an example of a terminal) of the other party, and reduce the wind noise contained in the user's voice.

[0115] Furthermore, according to the headphones 1 (an example of earphones) of the first embodiment, when the level of wind noise is below a predetermined value (-10 dBV) and the user U's speech is detected, the bandpass filter and volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 passes audio signals in a frequency band from 700 Hz to 4 kHz (an example of a third frequency band), which is higher than the frequency band of the wind noise, among the audio signals based on the user U's speech. The bandpass filter and volume adjustment unit 31 of the circuit board 20 also increases the volume level of the audio signals based on the user U's speech by +3 dB (an example of a third predetermined value). Thus, according to the headphones 1 or earphone control method of the first embodiment, even when the user U speaks through the headphones 1 with a relatively low level of wind noise, it is possible to adaptively adjust the characteristics of the user's voice to be transmitted to the smartphone P2 (an example of a terminal) of the other party, thereby reducing the wind noise contained in the user's voice.

[0116] Furthermore, according to the headphones 1 (an example of earphones) of the first embodiment, when the level of wind noise is below a predetermined value (-10 dBV) and no speech by the user U is detected, the bandpass filter and volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 passes audio signals of the ambient sound signals in a frequency band from 1 kHz to 3 kHz (an example of a fourth frequency band), which is higher than the frequency band of the wind noise. The bandpass filter and volume adjustment unit 31 of the circuit board 20 also adds -3 dB to the volume level of the ambient sound signals (i.e., reduces the volume by 3 dB (an example of the fourth predetermined value)). Thus, according to the headphones 1 or earphone control method of the first embodiment, even when the level of wind noise is relatively low and the user U does not speak through the headphones 1, it is possible to adaptively adjust the characteristics of the user voice to be transmitted to the smartphone P2 (an example of a terminal) of the other party, and reduce the wind noise contained in the user voice.

[0117] (Embodiment 2) A second embodiment of the present disclosure will be described with reference to Figures 7 and 8. Note that, since the description of the same or equivalent parts as those in the first embodiment described above will be repeated, the same reference numerals will be used in the drawings and the description thereof may be omitted or simplified.

[0118] [Background to the second embodiment] First, the circumstances leading to this embodiment will be described.

[0119] The configuration disclosed in WO 2018 / 163423 is capable of reducing wind noise when it occurs while listening to music playback. However, the configuration disclosed in WO 2018 / 163423 only reduces wind noise uniformly. For example, just as there are windy days and windy days, and wind strength varies depending on the time of day, wind conditions around the user can also vary. Therefore, there is room for improvement in reducing wind noise generated around the user in accordance with the user's situation (e.g., when receiving voice from a caller or listening to music on the user's own portable player).

[0120] In contrast, in this embodiment, it is possible to adaptively reduce wind noise contained in an audio signal or music signal depending on the wind conditions around the user and the operating mode specified by the user.

[0121] [Circuit board configuration] Next, the configuration of the circuit board 20 will be described with reference to Fig. 7. Fig. 7 is a hardware block diagram illustrating the processing on the circuit board 20 according to the second embodiment.

[0122] In this embodiment, an example is described in which the headphones 1 are used for music playback rather than for telephone calls, and in this example, the bandpass filter / volume adjustment unit 31 in the main circuit 30 does not operate. Similarly, in the ANC circuit 40, the second analog-to-digital conversion unit 42B, the sidetone filter unit 43, the feedforward filter unit 45, and the second digital addition unit 46B also do not operate. Similarly, in the detection circuit 50, the speech detection unit 51 and the beam forming unit 53 also do not operate. Therefore, in FIG. 7 , the blocks representing these units and the associated signal lines are shown with dotted lines. However, the disclosure of this embodiment can also be applied as appropriate to cases in which the headphones 1 are used for telephone calls.

[0123] 7, in this embodiment, the music playback / telephone mode switching unit 32 receives a music signal for playback transmitted from the smartphone P1 of the user U, and determines that the headphones are intended for music playback based on the reception result. The music playback / telephone mode switching unit 32 then switches the operation mode of the headphones 1 to music playback, and transmits the music signal input to the headphones 1 to the volume adjustment unit 33. When the headphones 1 are used for phone calls, the music playback / telephone mode switching unit 32 transmits the audio from the smartphone P2 of the other party.

[0124] The wind noise detection unit 52 of this embodiment detects the presence or absence of wind noise by detecting wind noise generated around the user U using two-channel analog signals output from the external microphone 8B and the speaking microphone 8C. The wind noise detection unit 52 also detects the level (strength) of wind noise. The wind noise detection unit 52 sends these detection results to the ambient filter and volume adjustment unit 44 of the ANC circuit 40.

[0125] In this embodiment, the ambient filter and volume adjustment unit 44 is set to on by the user U, and receives the two-channel audio digital signal output from the first analog-to-digital conversion unit 42A as the ambient sound signal. The ambient filter and volume adjustment unit 44 also receives the detection result from the wind noise detection unit 52.

[0126] The ambient filter and volume adjustment unit 44 then adjusts the characteristics (volume level) of the audio signals for these two channels based on the strength of wind noise and the input audio signal. At this time, a setting value for defining the volume level of the ambient sound signal is preset in the ambient filter and volume adjustment unit 44, and the volume level is adjusted based on this setting value. The user U can arbitrarily specify this setting value using an application on the smartphone P1, for example. This specification makes it possible to specify in advance the volume level at which the ambient sound of the user U should be output to the driver 10 under normal conditions.

[0127] The ambient filter and volume adjustment unit 44 sends the two-channel audio signals with their volume levels adjusted to the first digital adder 46A. The first digital adder 46A also receives a music signal from the main circuit 30, and adds these signals together.

[0128] In this way, the volume level is adjusted based on the strength of wind noise and the input audio signal or music signal through the operation of the ambient filter / volume adjustment unit 44 and the first digital adder 46A. As a result, the driver 10 outputs a music signal to which the ambient sound signal with the adjusted volume level has been added. Therefore, even if the wind conditions around the user U fluctuate, such as wind strength or its momentary changes, it is possible to adaptively reduce the wind noise contained in the audio signal or music signal in accordance with the wind conditions around the user U and the operating mode specified by the user U.

[0129] At this time, the feedback filter unit 48 generates an inverse phase signal of the feedback sound signal and outputs the inverse phase signal to the analog adder 49. In addition to the inverse phase signal, the music signal to which the ambient sound signal with its volume level adjusted has been added is also input to the analog adder 49. That is, the driver 10 ultimately outputs a signal obtained by adding the music signal to which the ambient sound signal with its volume level adjusted has been added and the inverse phase signal of the feedback sound signal.

[0130] [Processing flow for circuit boards] Next, a processing flow on the circuit board 20 according to this embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart illustrating a processing flow on the circuit board 20 shown in Fig. 7.

[0131] 8, the circuit board 20 determines whether or not the operation of the ambient filter / volume adjustment unit 44 has been set to on by the user U (S201). If it is determined that the ambient filter / volume adjustment unit 44 has not been set to on (NO in S201), the processing flow returns to step S201 again.

[0132] That is, unless the operation of the ambient filter / volume adjustment unit 44 is set to ON, the processing flow does not proceed to steps S202 and thereafter. In other words, setting the operation to OFF means that the user U has input a command to not add an ambient sound signal to the audio signal or music signal, and in this case, the circuit board 20 outputs the input audio signal or music signal directly from the driver 10.

[0133] On the other hand, if it is determined that the operation of the ambient filter / volume adjustment unit 44 is set to on (YES in S201), the above-mentioned setting value arbitrarily selected by the user U is read and set in the ambient filter / volume adjustment unit 44 (S202).

[0134] Next, wind noise detection unit 52 detects wind noise occurring around user U using two-channel digital signals from external microphone 8B and speaking microphone 8C, and determines whether wind noise is present (S203). If the determination result indicates that there is no wind noise (NO in S203), the processing flow returns to step S202. In other words, unless wind noise is detected, the processing flow does not proceed to steps S204 and beyond.

[0135] If it is determined that wind noise is present (YES in S203), the wind noise detection unit 52 detects the level of wind noise by determining whether the digital signals for two channels are equal to or greater than a pre-loaded threshold (S204). In this embodiment, the threshold is also set to -10 dBV.

[0136] If it is determined that the level of wind noise is equal to or greater than a predetermined value (-10 dBV) (YES in S204), the ambient filter / volume adjustment unit 44 reduces the volume level of the ambient sound signal to be added to the input music signal by 18 dB (an example of a first predetermined value) from the setting value set in step S202 (S205), and returns to step S203. Therefore, in this embodiment, even if the ambient filter / volume adjustment unit 44 is set to on when wind noise is relatively loud, as long as wind noise is detected, it is possible to adaptively reduce the wind noise contained in the audio signal or music signal in accordance with the wind conditions around the user U and the operation mode specified by the user U.

[0137] On the other hand, if it is determined that the level of wind noise is less than the predetermined value (-10 dBV) (NO in S204), the ambient filter / volume adjustment unit 44 reduces the volume level of the ambient sound signal to be added to the input music signal by 6 dB (an example of a second predetermined value) which is smaller than the set value set in step S202 (S206), and returns to step S203. Therefore, in this embodiment, even if the ambient filter / volume adjustment unit 44 is set to on when wind noise is relatively small, as long as wind noise is detected, it is possible to adaptively reduce the wind noise contained in the audio signal or music signal in accordance with the wind conditions around the user U and the operation mode specified by the user U.

[0138] As described above, the headphones 1 (an example of earphones) of embodiment 2 are headphones 1 worn by a user U, and include a plurality of microphones (an example of a sound collection unit) that collect ambient sounds around the user U, a music playback / telephone mode switching unit 32 (an example of an input unit) that can input an audio signal from a smartphone P2 (an example of a terminal) of the user U's call partner or a music signal for playback from the user U's smartphone P1 (an example of a terminal), a wind noise detection unit 52 that detects the presence or absence of wind noise around the user U based on the ambient sounds collected by each of the plurality of microphones, an ambient filter / volume adjustment unit 44 (an example of a signal processing unit) on a circuit board 20 that adjusts the characteristics of the ambient sound signal to be added to the audio signal or music signal based on the strength of the wind noise and the input of the audio signal or music signal, and a driver 10 (an example of a sound emission unit) that outputs an audio signal or music signal to which the ambient sound signal with adjusted characteristics has been added.

[0139] Furthermore, according to the earphone control method of embodiment 2, the earphone control method is an earphone control method using headphones 1 (an example of earphones) worn by a user U, and includes the steps of collecting ambient sounds around the user U at multiple locations (sound collection process), making it possible to input an audio signal from a smartphone P2 (an example of a terminal) of the user U's call partner or a music signal for playback from the user U's smartphone P1 (an example of a terminal) (input process), detecting the presence or absence of wind noise around the user U based on the ambient sounds collected in the sound collection process (wind noise detection process), adjusting the characteristics of the ambient sound signal to be added to the audio signal or music signal based on the strength of the wind noise and the input of the audio signal or music signal (signal processing process), and outputting the audio signal or music signal to which the ambient sound signal with the adjusted characteristics has been added (sound emission process).

[0140] As a result, according to the headphones 1 or earphone control method of embodiment 2, even if the wind conditions around the user U fluctuate, such as wind strength or instantaneous changes thereof, it is possible to adaptively reduce wind noise contained in an audio signal or music signal in accordance with the wind conditions around the user U and the operating mode specified by the user U.

[0141] Furthermore, according to the headphones 1 (an example of earphones) of the second embodiment, the ambient filter and volume adjustment unit 44 (an example of a signal processing unit) of the circuit board 20 reduces the volume level of the ambient sound signal added to the input audio signal or music signal by 18 dB (an example of a first predetermined value) from the set value when the level of wind noise is equal to or higher than a predetermined value (-10 dBV). As a result, according to the headphones 1 or earphone control method of the second embodiment, even when the ambient filter and volume adjustment unit 44 is set to on when wind noise is relatively loud, it is possible to adaptively reduce the wind noise included in the audio signal or music signal in accordance with the wind conditions around the user U and the operation mode specified by the user U.

[0142] Furthermore, according to the headphones 1 (an example of earphones) of the second embodiment, when the level of wind noise is below a predetermined value (-10 dBV), the ambient filter and volume adjustment unit 44 (an example of a signal processing unit) of the circuit board 20 reduces the volume level of the ambient sound signal added to the input audio signal or music signal by an even smaller amount of 6 dB (an example of a second predetermined value) from the set value. As a result, according to the headphones 1 or earphone control method of the second embodiment, even when the ambient filter and volume adjustment unit 44 is set to on when wind noise is relatively low, it is possible to adaptively reduce the wind noise included in the audio signal or music signal in accordance with the wind conditions around the user U and the operation mode specified by the user U.

[0143] Furthermore, according to the headphones 1 (an example of earphones) of the second embodiment, when a designation to not add an ambient sound signal to an audio signal or music signal is input, the ambient filter and volume adjustment unit 44 (an example of a signal processing unit) outputs the input audio signal or music signal from the driver 10 (an example of a sound emitting unit). As a result, according to the headphones 1 or earphone control method of the second embodiment, when the user U inputs a designation to not add an ambient sound signal to an audio signal or music signal, the operation of the ambient filter and volume adjustment unit 44 is set to off. Therefore, the input audio signal or music signal is output as is from the driver 10 without any ambient sound being added.

[0144] Furthermore, the headphones 1 (an example of earphones) of the second embodiment further include an internal microphone 8A (an example of a wraparound sound collection unit) that collects a wraparound sound signal of an audio signal or music signal output from a driver 10 (an example of a sound emission unit), and a feedback filter unit 48 (an example of a wraparound sound filter) that generates an inverse phase signal of the wraparound sound signal. The driver 10 also outputs a signal obtained by adding an audio signal or music signal to which an ambient sound signal with adjusted characteristics has been added, and an inverse phase signal of the wraparound sound signal. As a result, the headphones 1 or earphone control method of the second embodiment can actively remove noise from the user U's ambient sound that cannot be physically suppressed by the earpads 7 and that passes through the earpads 7 and enters the acoustic space 11 of the headphones 1. This allows the user U to hear a clearer audio signal or music signal.

[0145] (Embodiment 3) A third embodiment of the present disclosure will be described with reference to Figures 9 and 10. Note that, since the description of the same or equivalent parts as those in the first and second embodiments described above will be repeated, the same reference numerals will be used in the drawings and the description thereof may be omitted or simplified.

[0146] [Background to the Third Embodiment] First, the circumstances leading to this embodiment will be described.

[0147] The configuration disclosed in JP 2015-219527 A performs compensation using a signal containing acoustic noise components picked up by an internal microphone while the user is, for example, walking, making it possible to reduce acoustic noise signals contained in an audio signal. However, the configuration disclosed in JP 2015-219527 A does not anticipate that the user wearing the audio headset will be able to appropriately control noise reduction or the addition of ambient sounds based on the physical movement state of the user. As a result, there is room for improvement in the ability of the audio headset to adaptively reduce or incorporate ambient sounds, not only ambient sounds but also noise signals such as breathing sounds, the user's voice, and pulse sounds emitted from within the user's body, from the audio signal when the user wearing the audio headset is walking or talking to a person face-to-face.

[0148] In contrast, in this embodiment, the audio headset (in other words, headphones 1 as an example of earphones) is capable of adaptively reducing noise signals such as breathing sounds, the user's voice, pulse sounds, and other noise signals emitted from within the user's body, as well as ambient sounds, from the audio signal, or incorporating ambient sounds into the audio signal, depending on the physical movement or speaking state of the user wearing the audio headset.

[0149] [Circuit board configuration] Next, the configuration of the circuit board 20 will be described with reference to Fig. 9. Fig. 9 is a hardware block diagram illustrating the processing on the circuit board 20 according to the third embodiment.

[0150] In this embodiment, an example is described in which the headphones 1 are used for music playback rather than for telephone calls. As in the second embodiment, the band-pass filter / volume adjustment unit 31 in the main circuit 30 does not operate. Similarly, in the ANC circuit 40, the side tone filter unit 43, the feed-forward filter unit 45, and the second digital adder 46B do not operate. Similarly, in the detection circuit 50, the speech detection unit 51, the beam forming unit 53, and the wind noise detection unit 52 do not operate. For this reason, in FIG. 9, the blocks representing these units and the associated signal lines are shown with dotted lines. However, the disclosure of this embodiment can also be applied as appropriate to cases in which the headphones 1 are used for telephone calls.

[0151] 9, in this embodiment, the music playback / telephone mode switching unit 32 (an example of an input unit) receives a music signal for playback transmitted from the smartphone P1 of the user U, and determines that the headphones are intended for music playback based on the reception result. The music playback / telephone mode switching unit 32 then switches the operation mode of the headphones 1 to music playback, and transmits the music signal input to the headphones 1 to the volume adjustment unit 33. When the headphones 1 are used for phone calls, the music playback / telephone mode switching unit 32 transmits the audio from the smartphone P2 of the other party.

[0152] The bone conduction sensor 9 (an example of a vibration detection unit, which is an example of a detection unit) of this embodiment detects vibrations based on the movement of the user U. That is, as described above, the bone conduction sensor 9 is attached to the earphone so as to be able to come into contact with the surface of the face around the ear or the backside of the auricle, and detects vibrations of the human bones. Therefore, the bone conduction sensor 9 can detect not only vibrations associated with the voice spoken by the user U, but also vibrations caused by the movement of the user U's body.

[0153] The bone conduction sensor 9 transmits the detection results to the detection circuit 50 (an example of a signal processing unit, which is an example of a control unit, or an example of a periodic sound determination unit, which is an example of a control unit) via the second analog-digital conversion unit 42B. If the detection results of the bone conduction sensor 9 indicate that a periodic sound is being generated, it can be inferred that the user U is exercising, such as walking or running a marathon. Therefore, the detection circuit 50 determines whether or not a periodic sound is being generated based on the vibration detection results transmitted from the bone conduction sensor 9. At the same time, the detection circuit 50 also detects the vibration level. The detection circuit 50 transmits the determination result and the vibration level to the ANC circuit 40.

[0154] The ambient filter and volume adjustment unit 44 receives a digital signal based on the audio from the external microphone 8B, which is output from the first analog-to-digital conversion unit 42A. The ambient filter and volume adjustment unit 44 performs predetermined audio processing on this audio signal, adjusts its volume level, and sends the resulting signal to the first digital adder 46A. The first digital adder adds the digital audio signal sent from the ambient filter and volume adjustment unit 44 to the digital audio signal sent from the volume adjustment unit 33 of the main circuit 30, and sends the resulting signal to the second digital adder 46B.

[0155] In this way, the ambient sound picked up by the external microphone 8B is added to the audio signal from the smartphone P1. That is, in the present embodiment, the ambient filter / volume adjustment unit 44 and the first digital adder 46A constitute an ambient sound adding unit (an example of a control unit).

[0156] Furthermore, the feedback filter unit 48 converts the analog signal based on the internal microphone 8A into an inverse phase to generate an inverse phase signal, and outputs the inverse phase signal to the analog adder unit 49. The analog adder unit 49 adds the audio signal output from the digital-to-analog converter unit 47 and the audio signal (inverse phase signal) output from the feedback filter unit 48 as an analog signal, and outputs the added signal to the fourth amplifier unit 41D.

[0157] In this way, the feedback filter unit 48 and the analog adder 49 reduce noise contained in the audio signal from the smartphone P1 based on a signal that is picked up by the internal microphone 8A after a portion of the audio signal output from the driver 10 has been routed around to the internal microphone 8A. That is, in the present embodiment, the feedback filter unit 48 and the analog adder 49 form a noise reduction unit (an example of a control unit).

[0158] Here, the ANC circuit 40 of this embodiment controls the operation of the ambient filter / volume adjustment unit 44 and first digital adder 46A as an ambient sound addition unit, and the operation of the feedback filter unit 48 and analog adder 49 as a noise reduction unit, differently based on the result of the periodic sound determination.

[0159] [Processing flow for circuit boards] Next, a processing flow on the circuit board 20 according to this embodiment will be described with reference to Fig. 10. Fig. 10 is a flowchart illustrating a processing flow on the circuit board 20 shown in Fig. 9.

[0160] 10, the circuit board 20 determines whether the operation of the noise reduction section of the feedback filter unit 48 and the analog adder unit 49 is set to off (S301). If it is determined that the operation is not set to off (NO in S301), the process flow returns to step S301 again. In other words, the process flow does not proceed to step S302 or later unless the noise reduction section of the feedback filter unit 48 and the analog adder unit 49 is set to off.

[0161] On the other hand, if it is determined that the feedback filter unit 48 and the noise reduction unit of the analog adder unit 49 are set to off, the bone conduction sensor 9 detects vibrations based on the movement of the user U, and the detection circuit 50 receives the vibration results (S302).Then, the detection circuit 50 determines whether or not a periodic sound is being generated based on the vibration detection results transmitted from the bone conduction sensor 9 (S303).

[0162] If it is determined that a periodic sound is occurring (YES in S303), the detection circuit 50 detects the vibration level and determines whether the vibration level is equal to or greater than a predetermined value (-20 dBV) (S304). If it is determined that the vibration level is equal to or greater than the predetermined value (-20 dBV) (YES in S304), the detection circuit 50 transmits the determination result to the ANC circuit 40.

[0163] Here, in this case, it is presumed that the user U is engaged in vigorous exercise. Therefore, in order for the ANC circuit 40 to reduce noise in the acoustic space 11 that accompanies the vigorous exercise, the detection circuit 50 sets the operation of the noise reduction section of the feedback filter unit 48 and the analog adder unit 49 to on (S305), and returns to step S302. On the other hand, if the determination result indicates that the vibration level is less than the predetermined value (-20 dBV) (NO in S304), the detection circuit 50 does not change the operation settings of the noise reduction section of the feedback filter unit 48 and the analog adder unit 49, i.e., does nothing and returns to step S302.

[0164] If it is determined that no periodic sound is occurring (NO in S303), the circuit board 20 determines whether the operation of the ambient filter / volume adjustment unit 44 and the ambient sound addition unit of the first digital adder 46A is set to ON (S306). If it is determined that the operation is set to ON (YES in S306), the process flow returns to step S302 again. In other words, the process flow does not proceed to step S307 or later unless the ambient filter / volume adjustment unit 44 and the ambient sound addition unit of the first digital adder 46A are set to OFF.

[0165] On the other hand, if it is determined that the ambient filter / volume adjustment unit 44 and the ambient sound addition unit of the first digital adder 46A are set to off, the detection circuit 50 detects the vibration level and determines whether the vibration level is equal to or greater than a predetermined value (-40 dBV) (S307). If the determination result determines that the vibration level is equal to or greater than the predetermined value (-40 dBV) (YES in S307), it is assumed that the user U is speaking and conversing with those around them. Therefore, the ANC circuit 40 sets the operation of the ambient filter / volume adjustment unit 44 and the ambient sound addition unit of the first digital adder 46A to on to correspond to that operating mode (S308), and returns to step S302. On the other hand, if it is determined that the vibration level is less than the predetermined value (-40 dBV) (NO in S307), the ANC circuit 40 maintains the operation of the ambient filter / volume adjustment unit 44 and the ambient sound addition unit of the first digital adder 46A to off (S309), and returns to step S302.

[0166] In this way, based on the determination result of the periodic sound, the ANC circuit 40 controls differently the operation of the ambient sound adding unit (ambient filter / volume adjustment unit 44 and first digital adder 46A) and the noise reducing unit (feedback filter unit 48 and analog adder 49). This makes it possible to adaptively reduce noise signals included in the music signal from the user U's own smartphone P1 and incorporate ambient sounds according to the user U's physical movement state or speaking state.

[0167] As described above, the headphones 1 (an example of earphones) of the third embodiment are headphones 1 worn by a user U, and include an external microphone 8B (an example of a first sound collection unit which is an example of a sound collection unit) that collects sounds around the user U, an input unit (e.g., a music playback / telephone mode switching unit 32) that inputs a music signal (audio signal; the same applies below) from a terminal (e.g., a smartphone P1) of the user U, a bone conduction sensor 9 (an example of a vibration detection unit which is an example of a detection unit) that detects vibrations based on the movements of the user U, and a periodic sound based on the vibration detection results. The smartphone P1 includes a detection circuit 50 (an example of a periodic sound determination unit, which is an example of a control unit) that determines whether or not a periodic sound is occurring, an ambient filter and volume adjustment unit 44 and a first digital adder 46A (an example of an ambient sound addition unit) that add ambient sounds picked up by an external microphone 8B to a music signal from the smartphone P1, and an ANC circuit 40 (an example of a signal processing unit, which is an example of a control unit) on the circuit board 20 that changes the control by the ambient filter and volume adjustment unit 44 and the first digital adder 46A's ambient sound addition unit based on the result of the periodic sound determination.

[0168] Furthermore, the headphones 1 (an example of earphones) of the third embodiment further include an internal microphone 8A (an example of a second sound collection unit, which is an example of a sound collection unit) arranged in an acoustic space 11 including the pinna of the user U, a driver 10 (an example of a sound emission unit) that outputs a music signal from a terminal (e.g., a smartphone P1) of the user U, and a feedback filter unit 48 and an analog adder 49 (an example of a noise reduction unit) that reduce noise included in the music signal from the smartphone P1 based on a signal that is picked up by the internal microphone 8A after a portion of the music signal output from the driver 10 has been routed back to the internal microphone 8A. Furthermore, the ANC circuit 40 (an example of a signal processing unit, which is an example of a control unit) of the circuit board 20 controls the noise reduction units, namely the feedback filter unit 48 and the analog adder 49, and the ambient filter / volume adjustment unit 44 and the ambient sound addition unit, namely the first digital adder 46A, differently based on the determination result of the periodic sound.

[0169] Furthermore, according to the earphone control method of embodiment 3, the earphone control method is an earphone control method for headphones 1 (an example of earphones) worn by a user U, and includes the steps of collecting ambient sounds of the user U (sound collection process), inputting a music signal from the user U's terminal (e.g., a smartphone P1) (input process), detecting vibrations based on the movements of the user U (vibration detection process), determining whether or not a periodic sound is occurring based on the vibration detection result (periodic sound determination process), adding the ambient sound collected in the sound collection process to the music signal from the smartphone P1 (ambient sound addition process), and varying the control when adding the ambient sound based on the periodic sound determination result (signal processing process).

[0170] Therefore, it is possible to adaptively reduce noise signals included in the music signal from the user U's own smartphone P1 in accordance with the user U's physical movement state or speech state, and to capture ambient sounds.

[0171] Furthermore, the headphones 1 (earphones) of the third embodiment are headphones 1 worn by a user U, and include an internal microphone 8A (an example of a first sound collection unit, which is an example of a sound collection unit) that is arranged in an acoustic space 11 that includes the pinna of the user U, a driver 10 (an example of a sound emission unit) that outputs a music signal from a terminal of the user U (e.g., a smartphone P1), a bone conduction sensor 9 (an example of a vibration detection unit, which is an example of a detection unit) that detects vibrations based on the movement of the user U, a detection circuit 50 (an example of a periodic sound determination unit, which is an example of a control unit) that determines whether a periodic sound is occurring based on the vibration detection result, a feedback filter unit 48 and an analog addition unit 49 (an example of a noise reduction unit) that reduce noise included in the music signal from the smartphone P1 based on a signal that is picked up after a portion of the music signal output from the driver 10 has leaked into the internal microphone 8A, and an ANC circuit 40 (an example of a signal processing unit, which is an example of a control unit) on a circuit board 20 that changes the control by the noise reduction unit of the feedback filter unit 48 and the analog addition unit 49 based on the periodic sound determination result.

[0172] Furthermore, the headphones 1 (earphones) according to the third embodiment further include an external microphone 8B (an example of a second sound collection unit, which is an example of a sound collection unit) that collects ambient sounds around the user U, and an ambient filter and volume adjustment unit 44 and a first digital adder 46A (an example of an ambient sound addition unit) that add the ambient sounds collected by the external microphone 8B to a music signal from a terminal (e.g., a smartphone P1). The ANC circuit 40 (an example of a signal processing unit, which is an example of a control unit) on the circuit board 20 controls differently the noise reduction unit including the feedback filter unit 48 and the analog adder 49, and the ambient sound addition unit including the ambient filter and volume adjustment unit 44 and the first digital adder 46A, based on the determination result of the periodic sound.

[0173] Furthermore, according to the earphone control method of embodiment 3, the earphone control method is an earphone control method for headphones 1 (an example of earphones) worn by a user U, and includes the steps of: collecting music in the acoustic space 11 using an internal microphone 8A (an example of a sound collection unit) arranged in the acoustic space 11 including the auricle of the user U (sound collection process); outputting a music signal from the user U's smartphone P1 (an example of a terminal) (sound emission process); detecting vibrations based on the movement of the user U (vibration detection process); determining whether or not a periodic sound is being generated based on the vibration detection result (periodic sound determination process); reducing noise contained in the music signal from the smartphone P1 based on a signal collected by the internal microphone 8A that is part of the music signal output in the sound emission process (noise reduction process); and varying the control during noise reduction based on the periodic sound determination result (signal processing process).

[0174] Therefore, it is possible to adaptively reduce noise signals included in the music signal from the user U's own smartphone P1 in accordance with the user U's physical movement state or speech state, and to capture ambient sounds.

[0175] Although several embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention.

[0176] This application is based on Japanese patent applications filed on December 25, 2020 (Patent Application Nos. 2020-217010, 2020-217011, and 2020-217012), the contents of which are incorporated herein by reference. [Industrial Applicability]

[0177] The present disclosure is useful as an earphone and an earphone control method that can adaptively reduce not only ambient sounds but also noise signals such as breathing sounds, the user's voice, and pulse sounds emitted from within the user's body, depending on the physical movement or speaking state of the user wearing the audio headset, or that can incorporate ambient sounds into the audio signal.

[0178] The present disclosure is also useful as an earphone and an earphone control method that can adaptively reduce wind noise contained in an audio signal or music signal depending on the wind conditions around the user and the operating mode specified by the user.

[0179] Furthermore, the present disclosure is useful as an earphone and an earphone control method that can adaptively adjust the characteristics of the user's voice to be transmitted to the other party's terminal in accordance with the state of wind noise that may occur during a call with the other party, thereby reducing the wind noise contained in the user's voice. [Explanation of symbols]

[0180] 1 headphones 2 headbands 3 Main body 4. Housing 5 Opening 6 Partition 7 ear pads 8A Internal Microphone 8B External Microphone 8C Speech microphone 9 Bone conduction sensor 10 Drivers 11 Acoustic Space 12 Storage space 13. Mobile phone networks 20 Circuit Board 30 Main Circuit 31 Bandpass filter and volume control section 32 Music playback / telephone mode switch 33 Volume control section 40 ANC circuit 41A 1st amplifier section 41B Second amplifier section 41C 3rd amplifier section 41D 4th amplifier section 42A First analog-to-digital converter 42B Second analog-to-digital converter 43 Side tone filter section 44 Ambient filter and volume adjustment section 45 Feedforward filter section 46A First digital adder 46B Second digital adder 47 Digital-to-analog converter 48 Feedback filter section 49 Analog Adder 50 Detection circuit 51 Speech detection unit 52 Wind noise detector 53 Beam forming section

Claims

1. An earphone worn by a user, a first sound collection unit that collects ambient sounds around the user; a second sound collection unit disposed in an acoustic space including the user's pinna; a bone conduction sensor that detects vibrations based on the user's movements; a sound output unit that outputs a music signal from the user's terminal; a control unit that processes the output sound, The control unit a periodic sound determination unit that determines whether or not a periodic sound is being generated based on a result of vibration detection by the bone conduction sensor; an ambient sound adding unit that adds the ambient sound collected by the first sound collecting unit to a music signal from the terminal; a noise reduction unit that reduces noise included in the music signal from the terminal based on a signal collected by the second sound collection unit after a part of the music signal output from the sound emission unit has been absorbed; Further provided with The control unit When the determination result of the periodic sound determination unit is that the periodic sound is not generated, the operation of the ambient sound addition unit is set to ON when the level of the vibration detected by the bone conduction sensor is equal to or greater than a first predetermined value, and the operation of the ambient sound addition unit is set to OFF when the level of the vibration is less than the first predetermined value; and when the determination result of the periodic sound determination unit indicates that the periodic sound is being generated, the operation of the noise reduction unit is set to ON when the level of the vibration detected by the bone conduction sensor is equal to or greater than a predetermined value. Earphones.

2. 1. An earphone control method for earphones that are worn by a user and can output a music signal from a terminal of the user, comprising: collecting ambient sounds of the user by a first sound collection unit included in the earphone; detecting vibrations based on the user's movements using a bone conduction sensor included in the earphone; outputting a music signal from the user's terminal by a sound output unit of the earphone; and processing an output sound by a control unit included in the earphone, The control unit determining whether a periodic sound is being generated based on the vibration detection result by the bone conduction sensor; adding the ambient sound collected by the first sound collection unit to the music signal from the terminal; a second sound collection unit provided in the earphone and arranged in an acoustic space including the pinna of the user reduces noise included in the music signal from the terminal based on a signal collected by a part of the music signal output from the sound output unit; The control unit When it is determined that the periodic sound is not generated, the operation of adding the ambient sound is set to ON when the level of the vibration detected by the bone conduction sensor is equal to or greater than a first predetermined value, and the operation of adding the ambient sound is set to OFF when the level of the vibration is less than the first predetermined value; when it is determined that the periodic sound is being generated, the noise reduction operation is set to ON if the level of the vibration detected by the bone conduction sensor is equal to or greater than a predetermined value. Earphone control method.

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