Earphones and earphone control methods

Abstract

Based on the sound pickup signal collected by the sound pickup unit and the detection results from the detection unit, the system generates an optimal output sound for the earphone user and the person they are talking to. [Solution] The earphone is worn by the user and comprises a sound-collecting unit, a detection unit that detects the user's movements or the influence of the surroundings, and a control unit that processes the output sound based on the sound-collecting signal collected by the sound-collecting unit and the detection results from the detection unit. For example, it adaptively reduces noise signals such as the user's breathing sounds, voice, and pulse sounds as well as ambient noise, or incorporates ambient noise into the audio signal. Alternatively, it adaptively reduces wind noise contained in the voice signal or music signal. Alternatively, it adaptively adjusts the characteristics of the user voice used for transmission to the terminal of the person being called, thereby reducing wind noise contained in the user voice.

Description

Technical Field

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

Background Art

[0002] Among recent headphones, there have emerged those equipped with a microphone for picking up the voice of a user that is transmitted to a call partner via a communication terminal such as a smartphone, in addition to listening to music playback sound from a portable player. That is, as a transceiver device, recent headphones have been commercialized that have not only a driver function for simply outputting sound but also a microphone function for inputting voice.

[0003] Patent Document 1 discloses an audio headset that includes a motion sensor and compensates for an increase or decrease in air pressure in the acoustic cavity of the headset due to the walking movement of the user wearing it, thereby avoiding saturation reduction of a signal during movement detected by the motion sensor and reducing noise. This audio headset analyzes a signal picked up by an internal microphone disposed inside the acoustic cavity and a signal sent out by the motion sensor to verify whether a certain predetermined criterion is satisfied, and discloses a headset that selectively switches a saturation prevention filter according to the verification result.

[0004] Further, Patent Document 2 discloses a device including a first microphone for picking up ambient sound outside the outer ear canal of a user, a second microphone for picking up sound inside the ear canal, and a driver for emitting sound toward the ear canal. This headset discriminates the presence or absence of generation of wind noise by comparing a first signal based on the sound pickup of the first microphone and a second signal based on the sound pickup of the second microphone. And this headset discloses a headset that adds a signal input to the first signal (for example, a signal reproduced by an external device) and outputs it toward the driver when it is discriminated that wind noise is not generated.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2015-219527 [Patent Document 2] International Publication No. 2018 / 163423 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] This disclosure provides earphones and earphone control methods that can generate optimal output sound for the earphone user and the person they are talking to, based on the sound pickup signal picked up by the sound pickup unit and the detection result by the detection unit.

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

[0008] Furthermore, this disclosure provides earphones and earphone control methods 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, this disclosure provides earphones and earphone control methods that can adaptively adjust the characteristics of the user voice for transmission sent to the other party's terminal according to the state of wind noise that may occur during a call with the other party, thereby reducing wind noise contained in the user voice. [Means for solving the problem]

[0010] This disclosure provides an earphone worn by a user, comprising: a sound-receiving unit; a detection unit for detecting the user's movements or ambient influences; and a control unit for processing output sound based on the sound-receiving signal picked up by the sound-receiving unit and the detection result from the detection unit.

[0011] More specifically, the present disclosure provides an earphone worn by a user, comprising: a first sound-collecting unit for collecting ambient sounds of the user; an input unit for receiving a music signal from the user's terminal; a vibration detection unit for detecting vibrations based on the user's movements; a periodic sound determination unit for determining whether or not a periodic sound is being generated based on the vibration detection result; an ambient sound addition unit for adding the ambient sounds collected by the first sound-collecting unit to the music signal from the terminal; and a signal processing unit for differentiating the control performed by the ambient sound addition unit based on the periodic sound determination result.

[0012] Or, more specifically, the present disclosure provides an earphone worn by a user, comprising: a first sound-receiving unit disposed in the acoustic space including the user's auricle; a sound-emitting unit that outputs a music signal from the user's terminal; a vibration detection unit that detects vibrations based on the user's movements; a periodic sound determination unit that determines whether or not a periodic sound is being generated based on the vibration detection result; a noise reduction unit that reduces noise contained in the music signal from the terminal based on a signal that is picked up when a portion of the music signal output from the sound-emitting unit wraps around to the first sound-receiving unit; and a signal processing unit that causes the control by the noise reduction unit to differ based on the periodic sound determination result.

[0013] Or, more specifically, the present disclosure provides an earphone worn by a user, comprising: a plurality of sound-collecting units for collecting ambient sounds around the user; an input unit capable of receiving an audio signal from the terminal of the user's call partner or a music signal for playback from the user's terminal; a wind noise detection unit for detecting the presence or absence of wind noise around the user based on the ambient sounds collected by each of the plurality of sound-collecting units; a signal processing unit for adjusting the characteristics of an 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 sound emission unit for outputting the audio signal or music signal to which the ambient sound signal with the adjusted characteristics has been added.

[0014] Or, more specifically, the present disclosure provides an earphone worn by a user, comprising: a plurality of sound-collecting units for collecting ambient sounds around the user; a speech detection unit for detecting whether or not the user is speaking; a wind noise detection unit for detecting whether or not there is wind noise around the user based on the ambient sounds collected by each of the plurality of sound-collecting units; and a signal processing unit for adjusting the characteristics of an audio signal based on the user's speech based on whether or not the user is speaking and the wind noise detection results.

[0015] Furthermore, this disclosure provides an earphone control method for earphones worn by a user, comprising the steps of: collecting sound; detecting the user's movements or the influence of the surroundings; and processing the output sound based on the sound collected signal from the sound collected step and the detection result from the detection step.

[0016] More specifically, the present disclosure provides an earphone control method for earphones worn by a user, comprising: 4. the steps of: collecting ambient sounds of the user; 4. inputting a music signal from the user's terminal; 5. detecting vibrations based on the user's movements; 6. determining whether or not a periodic sound is being generated based on the vibration detection result; 7. adding the collected ambient sounds to the music signal from the terminal; and 8. differentiating the control when the ambient sounds are added based on the determination result of the periodic sound.

[0017] Or, more specifically, the present disclosure provides an earphone control method for earphones worn by a user, comprising the steps of: picking up music in the acoustic space with a sound-collecting unit placed in the acoustic space including the user's auricle; outputting a music signal from the user's terminal; detecting vibrations based on the user's movement; determining whether or not a periodic sound is being generated based on the vibration detection result; reducing noise contained in the music signal from the terminal based on the signal picked up by a portion of the output music signal wrapping around to the sound-collecting unit; and differentiating the control during noise reduction based on the determination result of the periodic sound.

[0018] Or, more specifically, the present disclosure provides an earphone control method for earphones worn by a user, comprising the steps of: collecting ambient sounds of the user at multiple locations; enabling input of an audio signal from the terminal of the user's call partner or a music signal for playback from the user's terminal; detecting the presence or absence of wind noise around the user based on the ambient sounds collected at the multiple locations; adjusting the characteristics of an ambient sound signal to be added to the audio signal or music signal based on the intensity of the wind noise and the input of the audio signal or music signal; and outputting the audio signal or music signal to which the ambient sound signal with the adjusted characteristics has been added.

[0019] Alternatively, more specifically, the present disclosure provides an earphone control method for an earphone worn by a user, the method comprising: receiving ambient sound of the user at a plurality of locations; detecting whether the user is speaking; detecting whether there is wind noise in the vicinity of the user based on the ambient sound received at the plurality of locations; and adjusting characteristics of an audio signal based on the user's speech based on the detection results of whether the user is speaking and whether there is wind noise.

Advantages of the Invention

[0020] According to the present disclosure, an optimal output sound can be generated for the user of the earphone or the call partner based on the sound reception signal received by the sound reception unit and the detection result by the detection unit.

[0021] Further, according to the present disclosure, in accordance with the motion state or speech state of the user's body, not only ambient sound but also noise signals such as breathing sounds emitted from within the user's body, the user's voice, and pulse sounds can be adaptively reduced, or ambient sound can be incorporated into the audio signal.

[0022] Furthermore, according to the present disclosure, the wind noise included in the voice signal or music signal can be adaptively reduced according to the wind state around the user and the operation mode specified by the user.

[0023] Moreover, according to the present disclosure, in accordance with the state of wind noise that may occur during a call with a call partner, the characteristics of the user voice for transmission to the call partner's terminal can be adaptively adjusted to reduce the wind noise included in the user voice.

Brief Description of the Drawings

[0024] [Figure 1] Side view illustrating a state in which the headphones of Embodiment 1 are worn on the user's head [Figure 2] Cross-sectional view schematically illustrating the internal hardware configuration of the headphones shown in FIG. 1 [Figure 3] Hardware block diagram illustrating the processing on the circuit board shown in Figure 2. [Figure 4] Figure 2 illustrates a schematic diagram showing a first method of active noise control using headphones. [Figure 5] A schematic diagram illustrating a second method of active noise control, which differs from the first method shown in Figure 3. [Figure 6] A flowchart illustrating the processing flow on the circuit board shown in Figure 3. [Figure 7] Hardware block diagram illustrating the processing on the circuit board of Embodiment 2. [Figure 8] A flowchart illustrating the processing flow on the circuit board shown in Figure 7. [Figure 9] Hardware block diagram illustrating the processing on the circuit board of Embodiment 3. [Figure 10] A flowchart illustrating the processing flow on the circuit board shown in Figure 9. [Modes for carrying out the invention]

[0025] Hereinafter, embodiments specifically disclosing the earphones and earphone control method according to this disclosure will be described in detail, with reference to the drawings as appropriate. However, unnecessarily detailed explanations may be omitted. For example, detailed explanations of already well-known matters and redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. Furthermore, each of the attached drawings should be referred to according to the direction of the reference numerals. Note that the attached drawings and the following explanation are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0026] For example, this disclosure describes overhead headphones worn on the user's head as an example of the disclosure, but is not limited to this, and may also apply to in-ear type earphones. In other words, this disclosure can also be applied to earphones that do not have a main body as a casing that surrounds or covers the ear and ear pads. Furthermore, as long as it has a driver and a microphone, the contents of this disclosure can be appropriately applied to any device used as an earphone, not limited to embodiments such as headphones or earphones.

[0027] Furthermore, the terms "part" or "device" in these embodiments are not limited to physical configurations mechanically implemented by hardware, but also include configurations whose functions are implemented by software such as programs. Moreover, the functions of one configuration may be implemented by two or more physical configurations, or the functions of two or more configurations may be implemented by, for example, one physical configuration.

[0028] (Embodiment 1) Embodiment 1 of this disclosure will be described based on Figures 1 to 6.

[0029] [Background to Embodiment 1] First, let me explain the background leading to this embodiment. In the configuration disclosed in International Publication No. 2018 / 163423, it is possible to reduce wind noise when wind noise occurs while listening to music playback. However, the configuration disclosed in International Publication No. 2018 / 163423 does not assume that wind noise will occur while a user wearing headphones is on a call with a party. Therefore, when wind noise occurs while a user is on a call with a party, it is difficult to reduce the wind noise contained in the user's speech (in other words, the voice signal sent to the communication partner), and there was room for improvement.

[0030] In contrast, this embodiment makes it possible to adaptively adjust the characteristics of the user voice transmitted to the other party's terminal (such as a smartphone) 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.

[0031] [Regarding the hardware configuration of headphones] The hardware configuration of the 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 the headphones 1 of Embodiment 1 when worn on the head of user U. Figure 2 is a schematic cross-sectional view illustrating the internal hardware configuration of the headphones 1 shown in Figure 1.

[0032] As shown in Figures 1 and 2, the headphones 1 of this embodiment are, for example, of the overhead type and consist of a headband 2 and a pair of main body parts 3 disposed at both ends of the headband 2. In this embodiment, the headphones 1 also have a wireless communication unit (not shown) that can communicate using the Bluetooth® communication standard, and are wirelessly connected to sound source devices such as radios or music players for music playback, or to telephone devices such as the user U's smartphone P1 (see Figure 3) for telephone use. The headphones 1 receive audio signals, music signals, and control signals transmitted from these devices, and output the audio signals as sound waves, or pick up the user U's speech and transmit the picked-up results to these devices.

[0033] In this embodiment, smartphones P1 and P2 are used as examples of devices that headphones 1 wirelessly communicate with, but the invention is not limited to these and can connect to various devices as long as they are capable of wireless communication. Furthermore, in the following description, unless otherwise specified, the term "audio signal" will also include the concept of a music signal.

[0034] The headband 2 is made of a long, elongated member and is formed in a roughly arc-shaped curve to allow for elasticity. When the headphones 1 are worn by user U, the headband 2 clamps the user U's head from both sides. As a result, the elasticity of the headband 2 allows the pair of main body parts 3 to press against the left and right sides of user U's head, thereby securing the headphones 1 to user U's head.

[0035] In this embodiment, the headband 2 may be provided with a pair of telescopic mechanisms, allowing the length of the headband 2 to be adjusted according to the size of the user U's head by extending or retracting each of these mechanisms.

[0036] Each of the pair of main body parts 3 is a component that comes into contact with the ear of the user U wearing the headphones 1, and is formed in a dome or egg shape. When the headphones 1 are worn on the user U's head, the pair of main body parts 3 are positioned to cover the user U's ears, and this position is the normal state of use for the headphones 1. Each of the pair of main body parts 3 is also composed of structural components including a housing 4, a partition plate 6, and an ear pad 7.

[0037] The housing 4 forms the outer casing of the main body 3, is dome-shaped, and has an opening 5. The housing 4 is attached to the headband 2 such that when the headphones 1 are worn by the user U, their openings 5 ​​are positioned facing each other, sandwiching the user U's head.

[0038] The partition plate 6 is a plate-shaped member that forms the inner casing of the main body 3 and is positioned 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 (see below) is fitted into this through hole and secured. The housing 4 and the partition plate 6 divide the storage space 12.

[0039] The ear pad 7 is formed in an annular shape and covers the ear of user U, who is wearing the headphones 1, by enveloping it from the sides. The ear pad 7 is positioned extending circumferentially around the periphery of the opening 5 of the housing 4. The ear pad 7 is made of a soft resin material and is provided so as to be deformable around user U's ear according to its shape. This deformation makes it possible to improve the airtightness between the ear pad 7 and the area around user U's ear. The acoustic space 11 is partitioned by the ear pad 7 and the partition plate 6. When the headphones 1 are worn by user U, the acoustic space 11 becomes a sealed space including user U's auricle at the contact area of ​​the ear pad 7.

[0040] Furthermore, in the acoustic space 11, the ear pads 7 physically suppress the leakage of sound 10 to the outside of the headphones 1 and the intrusion of ambient sound into the inside of the headphones 1.

[0041] Furthermore, each of the pair of main body sections 3 is composed of electrical and electronic components including a driver 10, multiple microphones (an example of a sound-collecting section), a bone conduction sensor 9 (an example of a vibration detection section, which is an example of a detection section), and a circuit board 20 (an example of a signal processing section).

[0042] 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 vibrates the diaphragm based on the audio signal input to the driver 10, thereby converting the audio signal into a sound wave (vibration of air). The sound wave output from the driver 10 propagates to the eardrum of the user U.

[0043] The multiple microphones consist of at least three types: an internal microphone 8A (an example of a sound-gathering pickup unit), an external microphone 8B, and a speech microphone 8C. In this embodiment, as will be described later, the external microphone 8B and the conversation microphone operate as sound-gathering devices that pick up ambient sounds around the user U.

[0044] The internal microphone 8A is positioned within the acoustic space 11, which is partitioned by the ear pad 7 and the partition plate 6, with its detection portion (not shown) facing the acoustic space 11. Furthermore, the internal microphone 8A is positioned as close as possible to the ear canal of the user U within the acoustic space 11. As a result, the internal microphone 8A captures sound that physically occurs within the acoustic space 11, including sound waves output from the driver 10.

[0045] In other words, the internal microphone 8A is provided to pick up noise that enters the acoustic space 11 through the housing 4 and ear pads 7, etc., as a feedback sound signal along with the audio signal or music signal output from the driver 10. The internal microphone 8A is also electrically connected to the circuit board 20 (see Figure 3) by signal lines.

[0046] The external microphone 8B and the speech microphone are housed in a storage space 12 partitioned by the housing 4 and the partition plate 6. The housing 4 has multiple through holes (not shown), and the external microphone 8B and the speech microphone 8C are attached to the housing 4 so that they can pick up external sounds from the headphones 1 through each of these through holes.

[0047] The external microphone 8B is positioned to pick up ambient noise (e.g., wind noise) from outside the headphones 1. The speech microphone 8C is positioned to pick up the speech of user U wearing headphones 1, and together with the driver 10, enables so-called hands-free calling when headphones 1 is able to communicate with a mobile phone device such as a smartphone P1.

[0048] The bone conduction sensor 9 is composed of a piezoelectric element (not shown) and other components, and converts vibrations transmitted to the user U's bones (bone conduction vibrations) into electrical signals. The bone conduction sensor 9 is attached to the headphones 1 so as to be in contact with the facial surface around the ear or the back of the auricle. In the acoustic space 11, the bone conduction sensor 9 is positioned at a distance from the driver 10. Since the sound uttered by the user U is conducted to the bones of their face and head, the sensor detects the vibrations of the bones and converts the detection result into an electrical signal for output. This electrical signal makes it possible to detect whether or not the user U is speaking. The bone conduction sensor 9 is electrically connected to the circuit board 20 (see Figure 3) by signal lines.

[0049] The circuit board 20 (see Figure 3) is formed in a flat shape, and multiple circuits are arranged on its surface. In other words, the circuit board 20 operates as a control board for the headphones 1, having multiple components such as a central processing circuit (not shown), a read-only memory circuit (not shown), and a writable memory circuit (not shown), and performs signal processing as appropriate.

[0050] [Regarding the circuit board configuration] Next, the configuration of the circuit board 20 will be described with reference to Figure 3. Figure 3 is a hardware block diagram illustrating the processing on the circuit board 20 shown in Figure 2.

[0051] As mentioned above, the circuit board 20 is configured as a general-purpose control board, and a program (not shown) as software stored in a memory device (not shown) provided on the control board is executed by an arithmetic unit (not shown), such as a central arithmetic circuit. In this embodiment, the circuit board 20 also has multiple integrated circuits mounted on it that specialize in performing predetermined processing as hardware physically mounted on the board. In other words, each block shown inside the circuit board 20 in Figure 3 represents either a function realized by software such as a program, or a function realized by hardware such as a dedicated integrated circuit.

[0052] Furthermore, in this embodiment, the functions realized by the circuit board 20 are realized by both software and hardware, but this is not limited to this. For example, all of the functions may be configured by hardware as part of the physical configuration of the "device".

[0053] Furthermore, as mentioned 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 user U via its wireless communication unit. In addition, user U with headphones 1 and the other smartphone P2, including the other party on the other end of the call, are both connected to the mobile phone network 13, and user U can make a call, that is, speak or transmit, to the other party via the mobile phone network 13 (see Figure 3). When speaking or transmitting, user U can use headphones 1 of this embodiment to make a so-called hands-free call. When making a hands-free call, the exchange of voice signals for speaking or transmitting takes place wirelessly between user U's smartphone P1 and headphones 1.

[0054] Furthermore, in this embodiment, the wireless communication unit of the headphones 1 communicates in accordance with the Bluetooth® communication standard, but is not limited to this, and may be provided to connect to communication lines such as WiFi® or mobile communication lines. Also, the mobile phone network 13 may include at least wired or wireless lines that enable communication between telephone devices such as smartphones P1, and may be configured to include part or all of the internet line. In addition, the mobile phone network 13 may be configured to include, as appropriate, local area networks (LANs), wide area networks (WANs), and other types of networks that are used to connect to each other in order to facilitate communication between telephone devices.

[0055] Furthermore, in this embodiment, the case where 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 summing unit 46B do not operate in the ANC circuit 40 (see dotted line).

[0056] As shown in Figure 3, the circuit board 20 is equipped with 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, 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). The main circuit 30, the detection circuit 50, and the ANC circuit 40 control each other in a consistent manner by sending and receiving control signals, and they also exchange audio signals as PCM (Pulse Code Modulation) digital signals.

[0057] The main circuit 30 is composed of a bandpass filter / volume control unit 31 (an example of a signal processing unit), a music playback / telephone mode switching unit 32 (an example of an input unit), and a volume control unit 33.

[0058] The bandpass filter / volume adjustment unit 31 receives control signals from the speech detection unit 51 (see below) and wind noise detection unit 52 (see below) of the detection circuit 50, and also receives the audio signal transmitted from the beamform unit 53 (see below) of the detection circuit 50 as a digital signal. Based on the control signals from the detection circuit 50, the bandpass filter / volume adjustment unit 31 allows audio components of a predetermined frequency band to pass through the received audio signal and adjusts the volume level of the passed audio signal (for example, an audio signal based on the user U's speech or an audio signal of ambient sound).

[0059] In other words, the bandpass filter / volume adjustment unit 31 adjusts the characteristics of the voice signal based on the user U's speech, based on whether or not the user U is speaking and the detection results of wind noise. This adjusted voice signal is wirelessly transmitted as a transmission signal to the user U's smartphone P1 via the wireless communication unit of the circuit board 20. The bandpass filter / volume adjustment unit 31 is configured to operate only when the headphones 1 are used for telephone purposes.

[0060] The music playback / phone mode switching unit 32 is wirelessly connected to the user U's smartphone P1 via wireless communication from the circuit board 20 and receives audio signals transmitted from the smartphone P1. In other words, the music playback / phone mode switching unit 32 is configured to accept audio signals or music signals for playback from the other party's smartphone P2. Based on the received audio signal or control signal transmitted from the smartphone P1, the music playback / phone mode switching unit 32 determines whether the operating mode (purpose) of the headphones 1 is for music playback or for phone calls and manages the input accordingly.

[0061] For example, in this embodiment, the music playback / telephone mode switching unit 32 receives the audio signal transmitted from the user U's call partner as a received signal and determines that it is for telephone use based on this reception result. The music playback / telephone mode switching unit 32 then switches the operating mode of the headphones 1 to telephone use and transmits the audio signal input to itself to the volume adjustment unit 33. The volume adjustment unit 33 adjusts the volume level of the transmitted audio signal and transmits it to the first digital summer 46A (see below) of the ANC circuit 40.

[0062] The ANC circuit 40 is composed of 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 side tone filter section 43, an ambient filter / volume adjustment section 44, a feedforward filter section 45, a first digital summer section 46A, a second digital summer section 46B, a digital-to-analog conversion section 47, a feedback filter section 48, and an analog summer section 49.

[0063] 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 it to the first analog-to-digital conversion section 42A.

[0064] Each of the second amplifier sections 41B is electrically connected to the speech microphone 8C, amplifies the audio signal output from the speech microphone 8C, and outputs it to the first analog-to-digital conversion section 42A.

[0065] The first analog-to-digital conversion unit 42A converts two channels of analog signals based on the speech microphone 8C or the external microphone 8B into digital signals. The first analog-to-digital conversion unit 42A transmits these two channels of digital signals to the sidetone filter unit 43, the ambient filter / volume control unit 44, the feedforward filter unit 45, and the beamform unit 53 of the detection circuit 50 (see below).

[0066] 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 the speech detection unit 51 (see below) of the detection circuit 50.

[0067] The sidetone filter unit 43 receives two channels of digital audio signals transmitted from the first analog-to-digital conversion unit 42A. These digital audio signals are based on the external microphone 8B and the speech microphone 8C, and the sidetone filter unit 43 transmits these digital audio signals to the first digital summer unit 46A.

[0068] In other words, when headphones 1 are used for telephone purposes, the external microphone 8B and the speech microphone 8C pick up the user U's speech. As a result of the operation of the sidetone filter unit 43, a portion of the user U's speech is looped back (added) to the audio signal output to the driver 10. This allows the user U to hear their own voice through headphones 1, making it easier to speak when headphones 1 are used for telephone purposes. The sidetone filter unit 43 is configured to operate only when headphones 1 are used for telephone purposes.

[0069] Similarly, the ambient filter / volume adjustment unit 44 receives the two-channel audio digital signals output from the first analog-to-digital conversion unit 42A. The ambient filter / volume adjustment unit 44 primarily extracts the low-frequency components from these two-channel audio signals, adjusts the volume level of the extracted components, and transmits them to the first digital summing unit 46A.

[0070] Under normal use, headphones 1 suppress the transmission of ambient sounds from the user U into the aforementioned acoustic space 11 by the ear pads 7 and other components. Therefore, when the ambient filter / volume control unit 44 is activated, ambient sounds such as vehicle noise and alarm sirens are actively taken in through the external microphone 8B and the speech microphone 8C, and electrically allowed to pass these ambient sounds from the outside world into the user U's ear canal. As a result, user U can be aware of the ambient sound situation even when wearing headphones 1.

[0071] The ambient filter / volume control unit 44 is controlled to turn on or off by an operating system or application installed on a smartphone P1 or the like, and in this embodiment, the ambient filter / volume control unit 44 is set to off. Therefore, in Figure 3, the block representing the ambient filter / volume control unit 44 and its associated signal lines are shown with dotted lines.

[0072] 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 filters the signal, focusing on the mid-range (mid-frequency) components which contain a large amount of human voice, and transmits the processing result to the second digital summer unit 46B. In this embodiment, the feedforward filter unit 45 is also set to off. Therefore, in Figure 3, the block representing the feedforward filter unit 45 and its associated signal lines are shown with dotted lines.

[0073] The first digital summer 46A adds the digital audio signal transmitted from the side tone filter 43 or ambient filter / volume control 44 and the digital audio signal transmitted from the volume control 33 of the main circuit 30, and then transmits the result to the second digital summer 46B.

[0074] The second digital adder 46B receives the digital audio signals transmitted from the first digital adder 46A and the feedforward filter unit 45, adds these digital signals, and transmits the summation result to the digital-to-analog converter 47. In this embodiment, the feedforward filter unit 45 is set to off, so the second digital adder 46B has no input and simply passes the transmission from the first digital adder 46A through (through control). Therefore, in Figure 3, the block diagram representing the second digital adder 46B is shown with a dotted line.

[0075] The digital-to-analog conversion unit 47 converts the summation result into an analog signal and outputs the converted analog signal to the analog summer unit 49.

[0076] The third amplifier section 41C is electrically connected to the internal microphone 8A and amplifies the audio signal (i.e., the stray sound signal) output from the internal microphone 8A and outputs it to the feedback filter section 48.

[0077] The feedback filter unit 48 converts the analog signal based on the internal microphone 8A to an inverse phase to generate an inverse phase signal, which is then output to the analog summer unit 49.

[0078] The analog summing unit 49 adds the audio signal output from the digital-to-analog conversion unit 47 and the audio signal (inverse phase signal) output from the feedback filter unit 48 as an analog signal and outputs it to the fourth amplifier unit 41D.

[0079] As mentioned above, the internal microphone 8A picks up noise that cannot be suppressed by the ear pad 7 and enters the acoustic space 11, along with the audio signal or music signal output from the driver 10, as feedback noise. The feedback filter unit 48 converts the audio signal of this picked-up feedback noise into an inverse phase to generate an inverse phase signal of the analog signal. The analog summer unit 49 adds this inverse phase signal to the analog signal just before it is output to the driver 10. By adding these analog signals, it becomes possible to actively remove the aforementioned noise.

[0080] In this way, the feedback filter unit 48 and the analog summing 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 after a portion of the audio signal output from the driver 10 has been fed back into it.

[0081] The fourth amplifier section 41D is electrically connected to the driver 10 and amplifies the analog signal output from the analog summer 49 and outputs it to the driver 10. Based on this input, the driver 10 outputs a signal such as an audio signal or a music signal as physical air vibrations (sound waves).

[0082] Similarly, the operation of the feedback filter unit 48 and the analog summer unit 49 is controlled by an application installed on a smartphone P1 or the like, and the user U can arbitrarily change their on / off status. If the user U sets them to off, a control signal related to this setting is sent to the analog summer unit 49. Based on this control signal, the analog summer unit 49 controls itself so that the audio signal from the feedback filter unit 48 is not input to it.

[0083] The detection circuit 50 includes a speech detection unit 51, a wind noise detection unit 52, and a beamform unit 53.

[0084] The speech detection unit 51 is connected to the second analog-to-digital conversion unit 42B of the ANC circuit 40 and receives a digital signal transmitted from the second analog-to-digital conversion unit 42B. This digital signal is based on 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 determines (detects) whether or not the user U is speaking. This detection result is transmitted as a control signal to the beamform unit 53 and the bandpass filter / volume control 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 purposes.

[0085] The wind noise detection unit 52 (an example of a detection unit) is directly electrically connected to the external microphone 8B and the speech microphone 8C, and receives the analog signal before it is amplified by the first amplifier unit 41A and the second amplifier unit 41B. This analog signal is a two-channel analog signal based on the external microphone 8B and the speech microphone 8C, and the wind noise detection unit 52 detects the wind noise generated around the user U using these two-channel analog signals to determine (detect) whether or not wind noise is present. Furthermore, the wind noise detection unit 52 can also detect the level (strength) of the wind noise by, for example, reading a threshold value stored in the memory device of the circuit board 20 in advance and determining whether or not the two-channel digital signal is above a predetermined threshold value.

[0086] Specifically, the wind noise detection unit 52 in this embodiment calculates the correlation between the two channels of ambient sound picked up by the external microphone 8B and the speech microphone 8C, and the intensity levels of those ambient sounds. Since general speech is often correlated with each other, the wind noise detection unit 52 determines that wind noise is present if the two channels of ambient sound are uncorrelated and their intensity levels are high. In this way, the wind noise detection unit 52 detects the presence or absence of wind noise around the user U based on the ambient sound picked up by the external microphone 8B and the speech microphone 8C, and in this embodiment, transmits this detection result to the bandpass filter / volume adjustment unit 31 of the main circuit 30.

[0087] The beamform unit 53, like the wind noise detection unit 52, is connected to the first analog-to-digital conversion unit 42A of the ANC circuit 40 and receives the digital signal transmitted from the first analog-to-digital conversion unit 42A. The beamform unit 53 performs audio processing on these two channels of digital signals to suppress sounds other than the user U's speech. Through this audio processing, the beamform unit 53 increases the directivity of the sound physically emitted from the user U's mouth, and as a result, it becomes possible to transmit (speak) a voice that is easy for the other party to hear during so-called hands-free calls. In this way, the beamform unit 53 transmits a digital signal of the voice with increased directivity to the user U's mouth to the bandpass filter / volume control unit 31. The beamform unit 53 is provided to operate only when the headphones 1 are used for telephone purposes.

[0088] [Overview of Active Noise Control] Next, referring to Figures 4 and 5, two methods of active noise control performed in the ANC circuit 40, including the feedback filter section 48, will be illustrated. Figure 4 is a schematic diagram illustrating the first method of active noise control in the headphones 1 shown in Figure 2. Figure 5 is a schematic diagram illustrating the second method of active noise control, which differs from the first method shown in Figure 3. Note that the first method is ideal, and the second method is actually used.

[0089] As shown in Figure 4, in the first method, the audio (original sound) output through the music playback / phone mode switching unit 32 is physically combined with ambient noise (such as wind noise) from the user U's surroundings that could not be physically suppressed by the ear pad 7 in the acoustic space 11. If left as is, this audio with added noise would be transmitted through the middle ear of the user U. However, the ANC circuit 40 of the circuit board 20 picks up this audio with added noise using the internal microphone 8A, and converts the picked-up audio signal to an inverse phase to generate an inverse phase signal.

[0090] In the first method, within the acoustic space 11 including the middle ear of user U, both the noise-infused sound and its inverse phase signal are physically output and added together, causing these sounds to cancel each other out. As a result, the middle ear of user U theoretically becomes silent, and in this silent state, the sound (original sound) is output again through the music playback / telephone mode switching unit 32.

[0091] In this way, the first method ideally reproduces a sound identical or very similar to the original sound with noise actively removed, and transmits it within the middle ear of user U.

[0092] However, while this first method is ideal for active noise control, it is difficult to implement it 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, which will be described next.

[0093] As shown in Figure 5, in the practical second method, instead of a silent state being created, the audio (original sound) output through the music playback / telephone mode switching unit 32 is amplified and output, and noise from the user U's surroundings is physically added to this amplified audio. At this time, the ANC circuit 40 of the circuit board 20 converts the audio signal to an inverse phase, similar to the first method described above, for the audio before amplification, i.e., the audio with noise added to the original sound, and generates an inverse phase signal.

[0094] In the second method, both the amplified and noise-infused audio signal and its inverse phase signal are physically output and added together within the acoustic space 11, including the middle ear of user U. Since the noise levels are equivalent between these audio signals, the original sound components remain while the noise components are mainly removed.

[0095] In this way, similarly in the second method, a sound identical or very similar to the original sound is practically reproduced with noise actively removed and transmitted within the middle ear of user U. In this embodiment, the second method described above is applied.

[0096] [Regarding the processing flow on the circuit board] Next, the processing flow in the circuit board 20 according to this embodiment will be described with reference to Figure 6. Figure 6 is a flowchart illustrating the processing flow in the circuit board 20 shown in Figure 3.

[0097] As shown in Figure 6, the music playback / telephone mode switching unit 32 determines whether the operating mode (purpose) of the audio output of headphones 1 is for telephone use (S101). If the determination result is that it is 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 beyond unless the operating mode of headphones 1 is set to telephone use.

[0098] On the other hand, if it is determined that the device is for telephone use (YES in S101), the wind noise detection unit 52 detects wind noise generated around the user U using two channels of digital signals based on the external microphone 8B and the speech microphone 8C, and determines whether or not there is wind noise (S102). If the determination result indicates that there is no wind noise (NO in S102), the bandpass filter / volume adjustment unit 31 passes audio components in the frequency band from 300Hz to 8kHz, but transmits the audio signal at its original volume level without adjusting it (without increasing or decreasing the volume level) (S110).

[0099] If wind noise is detected (YES in S102), the wind noise detection unit 52 detects the level of wind noise by determining whether the digital signals for the two channels are above a pre-read threshold (S103). In this embodiment, the threshold is set to -10 dBV.

[0100] If the wind noise level is determined to be above a predetermined value (-10dBV) (YES in S103), the speech detection unit 51 determines whether or not user U is speaking based on the digital signal from the bone conduction sensor 9 (S104). If the determination result indicates that user U is speaking (YES in S104), the bandpass filter / volume adjustment unit 31 allows speech components in the frequency band from 1kHz to 4kHz of the speech signal based on user U's speech to pass through. Furthermore, the bandpass filter / volume adjustment unit 31 increases the volume level of the passed-through speech signal by +6dB (S105).

[0101] In other words, the bandpass filter / volume adjustment unit 31, when the wind noise level is above a predetermined value (-10 dBV) and user U's speech is detected, allows the audio signal based on user U's speech to pass through in the frequency band from 1 kHz to 4 kHz (an example of the first frequency band), which is higher than the frequency band of the wind noise. Furthermore, the bandpass filter / volume adjustment unit 31 increases the volume level of the audio signal that has passed through in that frequency band, i.e., the audio signal based on user U's speech, by +6 dB (an example of the first predetermined value). Therefore, in this embodiment, even when user U speaks through headphones 1 while the wind noise level is relatively high, it is possible to adaptively adjust the characteristics of the user voice for transmission sent to the other party's smartphone P2, thereby reducing the wind noise contained in the user voice.

[0102] If it is determined that there is no speech from user U (NO in S104), the sound picked up by the external microphone 8B and the speech microphone 8C in this case is ambient sound, and the bandpass filter / volume adjustment unit 31 passes speech components in the frequency band from 2kHz to 3kHz. Furthermore, the bandpass filter / volume adjustment unit 31 adjusts the volume level of the passed speech signal by reducing it by 6dB (i.e., by adding -6dB) (S106).

[0103] In other words, the bandpass filter / volume adjustment unit 31, when the wind noise level is above a predetermined value (-10 dBV) and no speech is detected from the user U, allows audio signals in the frequency band from 2 kHz to 3 kHz (an example of a second frequency band), which are higher than the frequency band of the wind noise, to pass through. Furthermore, the bandpass filter / volume adjustment unit 31 adds -6 dB (an example of a second predetermined value) to the volume level of the audio signal that has passed through in that frequency band, i.e., the ambient noise signal (i.e., it is reduced 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 for transmission to the smartphone P2 of the person on the other end of the call, thereby reducing the wind noise contained in the user voice.

[0104] On the other hand, if the wind noise level is determined to be less than a predetermined value (-10dBV) (NO in S103), the speech detection unit 51 determines whether or not user U is speaking (S107). If the determination result indicates that user U is speaking (YES in S107), the bandpass filter / volume adjustment unit 31 passes through the audio signal based on user U's speech in the frequency band from 700Hz to 4kHz. Furthermore, the bandpass filter / volume adjustment unit 31 increases the volume level of the passed audio signal by +3dB (S10248).

[0105] In other words, the bandpass filter / volume adjustment unit 31, when the wind noise level is below a predetermined value (-10 dBV) and user U's speech is detected, allows the audio signal based on user U's speech to pass through in the 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. Furthermore, the bandpass filter / volume adjustment unit 31 increases the volume level of the audio signal passed through in that frequency band, i.e., the audio signal based on user U's speech, by +3 dB (an example of a third predetermined value). Therefore, in this embodiment, even when user U speaks through headphones 1 with a relatively low wind noise level, it is possible to adaptively adjust the characteristics of the user voice for transmission to the other party's smartphone P2 and reduce the wind noise contained in the user voice.

[0106] If it is determined that there is no speech from user U (NO in S107), the bandpass filter / volume adjustment unit 31 of the circuit board 20 allows speech components in the frequency band from 1kHz to 3kHz to pass through. Furthermore, the bandpass filter / volume adjustment unit 31 adjusts the volume level of the passed speech signal by reducing it by 3dB (i.e., by adding -3dB) (S109).

[0107] In other words, the bandpass filter / volume adjustment unit 31 of the circuit board 20 allows audio signals in the frequency band from 1kHz to 3kHz (an example of the fourth frequency band), which are higher than the frequency band of the wind noise, to pass through when the wind noise level is below a predetermined value (-10dBV) and no speech from user U is detected. Furthermore, the bandpass filter / volume adjustment unit 31 of the circuit board 20 adds -3dB (an example of the fourth predetermined value) to the volume level of the audio signal that has passed through in that frequency band, i.e., the ambient noise signal (i.e., it is reduced by 3dB). Therefore, in this embodiment, even when the wind noise level is relatively low and user U does not speak through headphones 1, it is possible to adaptively adjust the characteristics of the user voice for transmission sent to the other party's smartphone P2, thereby reducing the wind noise contained in the user voice.

[0108] In this way, the circuit board 20 detects the presence or absence of wind noise around user U based on ambient sound picked up by multiple microphones, and adjusts the characteristics of the voice signal based on user U's speech based on the presence or absence of user U's speech and the wind noise detection results. Therefore, in this embodiment, it is possible to adaptively adjust the characteristics of the user voice for transmission to the other party's smartphone P2 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.

[0109] As described above, according to the headphones 1 (an example of earphones) of Embodiment 1, the headphones 1 worn by user U include a plurality of microphones (an example of a sound-collecting unit) that pick up ambient sounds around user U, a speech detection unit 51 that detects whether or not user U is speaking, a wind noise detection unit 52 that detects whether or not wind noise is present around user U based on ambient sounds picked up by each of the plurality of microphones, and a bandpass filter / volume adjustment unit 31 (an example of a signal processing unit) of a circuit board 20 that adjusts the characteristics of the audio signal based on user U's speech based on the detection results of whether or not user U is speaking and wind noise.

[0110] Furthermore, according to the earphone control method of Embodiment 1, the earphone control method for headphones 1 (an example of earphones) worn by user U comprises the steps of: collecting ambient sounds of user U at multiple locations (sound collection step); detecting whether or not user U is speaking (speech detection step); detecting whether or not wind noise is present around user U based on the ambient sounds collected in the sound collection step (wind noise detection step); and adjusting the characteristics of the voice signal based on user U's speech based on the detection results of whether or not user U is speaking and the wind noise (signal processing step).

[0112] As a result, according to the headphones 1 or earphone control method of Embodiment 1, the characteristics of the user voice for transmission to be sent to the other party's smartphone P2 (an example of a 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.

[0111] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 1, the bandpass filter / volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 allows the audio signal from the audio signal based on the user U's speech in the frequency band from 1kHz to 4kHz (an example of a first frequency band), which is higher than the frequency band of the wind noise, to pass through when the wind noise level is above a predetermined value (-10dBV) and the user U's speech is detected. In addition, the bandpass filter / volume adjustment unit 31 of the circuit board 20 increases the volume level of the audio signal based on the user U's speech by +6dB (an example of a first predetermined value). As a result, according to the headphones 1 or earphone control method of Embodiment 1, even when the wind noise level is relatively high and the user U speaks through the headphones 1, the characteristics of the user voice for transmission to the other party's smartphone P2 (an example of a terminal) can be adaptively adjusted, and the wind noise contained in the user voice can be reduced.

[0112] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 1, the bandpass filter / volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 allows audio signals in the frequency band from 2kHz to 3kHz (an example of a second frequency band), which is higher than the frequency band of the wind noise, to pass through when the wind noise level is above a predetermined value (-10dBV) and no speech from user U is detected. In addition, the bandpass filter / volume adjustment unit 31 of the circuit board 20 adds -6dB to the volume level of the ambient noise signal (i.e., it decreases by 6dB (an example of a second predetermined value)). As a result, according to the headphones 1 or earphone control method of Embodiment 1, even when the wind noise level is relatively high and user U does not speak through the headphones 1, the characteristics of the user voice for transmission sent to the other party's smartphone P2 (an example of a terminal) can be adaptively adjusted, and the wind noise contained in the user voice can be reduced.

[0113] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 1, the bandpass filter / volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 allows audio signals from the audio signal based on user U's speech in the frequency band from 700Hz to 4kHz (an example of a third frequency band), which is higher than the frequency band of the wind noise, to pass through when the wind noise level is below a predetermined value (-10dBV) and user U's speech is detected. In addition, the bandpass filter / volume adjustment unit 31 of the circuit board 20 increases the volume level of the audio signal based on user U's speech by +3dB (an example of a third predetermined value). As a result, according to the headphones 1 or earphone control method of Embodiment 1, even when 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 voice for transmission to the other party's smartphone P2 (an example of a terminal) and reduce the wind noise contained in the user voice.

[0114] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 1, the bandpass filter / volume adjustment unit 31 (an example of a signal processing unit) of the circuit board 20 allows audio signals in the frequency band from 1kHz to 3kHz (an example of a fourth frequency band), which are higher than the frequency band of the wind noise, to pass through when the wind noise level is below a predetermined value (-10dBV) and no speech from user U is detected. In addition, the bandpass filter / volume adjustment unit 31 of the circuit board 20 adds -3dB to the volume level of the ambient sound signal (i.e., it decreases by 3dB (an example of a fourth predetermined value)). As a result, according to the headphones 1 or earphone control method of Embodiment 1, even when the wind noise level is relatively low and user U does not speak through the headphones 1, the characteristics of the user voice for transmission to the other party's smartphone P2 (an example of a terminal) can be adaptively adjusted, and the wind noise contained in the user voice can be reduced.

[0115] (Embodiment 2) Embodiment 2 of this disclosure will be described with reference to Figures 7 and 8. Note that parts identical or equivalent to those in Embodiment 1 described above may be denoted by the same reference numerals in the drawings, and their descriptions may be omitted or simplified, as the explanation would be redundant.

[0116] [Regarding the process leading to Embodiment 2] First, I will explain the background leading to this embodiment.

[0117] The configuration disclosed in International Publication No. 2018 / 163423 makes it possible to reduce wind noise when it occurs while listening to music playback. However, the wind noise reduction in this configuration is only uniform. For example, the wind conditions around the user can fluctuate, such as on windy or slack days, or depending on the time of day. Therefore, there was room for improvement in reducing wind noise around the user according to the user's situation (for example, when receiving a call from someone else, or when listening to music from their portable player).

[0118] In contrast, this embodiment makes it possible to adaptively reduce wind noise contained in the audio signal or music signal according to the wind conditions around the user and the operating mode specified by the user.

[0119] [Regarding the circuit board configuration] Next, the configuration of the circuit board 20 will be described with reference to Figure 7. Figure 7 is a hardware block diagram illustrating the processing on the circuit board 20 of Embodiment 2.

[0120] In this embodiment, the case where headphones 1 are used for music playback rather than telephone use is described as one example, and in the main circuit 30, the bandpass filter and volume control unit 31 do 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 summer unit 46B do not operate. Similarly, in the detection circuit 50, the speech detection unit 51 and the beamform unit 53 do not operate. Therefore, in Figure 7, the blocks representing these units and their associated signal lines are shown with dotted lines. However, it is possible to appropriately apply the disclosures of this embodiment even when headphones 1 are used for telephone use.

[0121] As shown in Figure 7, in this embodiment, the music playback / telephone mode switching unit 3229 receives a music signal for playback transmitted from user U's smartphone P1 and determines that it is for music playback based on this reception result. The music playback / telephone mode switching unit 32 then switches the operating mode of the headphones 1 to music playback and transmits the music signal input to itself to the volume control unit 33. When the headphones 1 are used for telephone purposes, the music playback / telephone mode switching unit 32 will transmit the audio from the other party's smartphone P2.

[0122] In this embodiment, the wind noise detection unit 52 detects wind noise generated around the user U using two channels of analog signals output from the external microphone 8B and the speech microphone 8C, and determines (detects) the presence or absence of wind noise. Furthermore, the wind noise detection unit 52 also detects the level (intensity) of the wind noise. The wind noise detection unit 52 transmits these detection results to the ambient filter / volume adjustment unit 44 of the ANC circuit 40.

[0123] In this embodiment, the ambient filter / volume control unit 44 is set to ON by user U and receives two channels of digital audio signals output from the first analog-to-digital conversion unit 42A as ambient sound signals. The ambient filter / volume control unit 44 also receives the detection results from the wind noise detection unit 52.

[0124] The ambient filter / volume adjustment unit 44 then adjusts the characteristics (volume level) of these two channels of audio signals based on the strength of the wind noise and the input of the audio signals. At this time, the ambient filter / volume adjustment unit 44 has a preset value for defining the volume level of the ambient sound signal, and adjusts the volume level based on this preset value. User U can arbitrarily specify this preset value using an application on the smartphone P1. This specification makes it possible to pre-define what volume level the ambient sound of user U should be output to the driver 10 under normal conditions.

[0125] The ambient filter / volume adjustment unit 44 transmits the audio signals for these two channels, whose volume levels have been adjusted, to the first digital summer unit 46A. The first digital summer unit 46A also receives music signals from the main circuit 30, and the first digital summer unit 46A adds these signals together.

[0126] In this way, the ambient filter / volume adjustment unit 44 and the first digital summing unit 46A operate to adjust the volume level based on the strength of the wind noise and the input of the audio signal or music signal. 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 when the wind conditions around the user U fluctuate, such as the strength of the wind or instantaneous changes in the wind, it is possible to adaptively reduce the wind noise included in the audio signal or music signal according to the wind conditions around the user U and the operating mode specified by the user U.

[0127] At this time, the feedback filter unit 48 generates an inverse phase signal of the eavesdropping sound signal and outputs this inverse phase signal to the analog summer unit 49. The analog summer unit 49 receives not only this inverse phase signal, but also a music signal to which an ambient sound signal with an adjusted volume level has been added. In other words, the driver 10 ultimately outputs a signal that is the sum of the music signal to which the ambient sound signal with an adjusted volume level has been added, and the inverse phase signal of the eavesdropping sound signal.

[0128] [Regarding the processing flow on the circuit board] Next, the processing flow in the circuit board 20 according to this embodiment will be described with reference to Figure 8. Figure 8 is a flowchart illustrating the processing flow in the circuit board 20 shown in Figure 7.

[0129] As shown in Figure 8, the circuit board 20 determines whether the operation of the ambient filter / volume control unit 44 is set to ON by user U (S201). If the determination result is that it is not set to ON (NO in S201), the processing flow returns to step S201 again.

[0130] In other words, unless the operation of the ambient filter / volume control unit 44 is set to ON, the processing flow will not proceed to steps S202 and beyond. That is, setting its operation to OFF means that user U has input a specification that ambient sound signals should not be added to the audio signal or music signal, and in this case, the circuit board 20 outputs the input audio signal or music signal from the driver 10 as is.

[0131] On the other hand, if it is determined that the operation of the ambient filter / volume control unit 44 is set to ON (YES in S201), the aforementioned setting value arbitrarily selected by the user U is read and set in the ambient filter / volume control unit 44 (S202).

[0132] Next, the wind noise detection unit 52 detects wind noise generated around the user U using two channels of digital signals based on the external microphone 8B and the speech microphone 8C, and determines whether or not wind noise is present (S203). If the determination result is 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.

[0133] If wind noise is detected (YES in S203), the wind noise detection unit 52 detects the level of wind noise by determining whether the digital signals for the two channels are above a pre-read threshold (S204). In this embodiment as well, the threshold is set to -10 dBV.

[0134] If the wind noise level is determined to be above a predetermined value (-10 dBV) (YES in S204), the ambient filter / volume adjustment unit 44 reduces the volume level of the ambient sound signal added to the input music signal by 18 dB (an example of a first predetermined value) from the set 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 the wind noise is relatively high, as long as wind noise is detected, it is possible to adaptively reduce the wind noise included in the audio signal or music signal according to the wind conditions around the user U and the operating mode specified by the user U.

[0135] On the other hand, if the wind noise level is determined to be less than a predetermined value (-10 dBV) (NO in S204), the ambient filter / volume adjustment unit 44 reduces the volume level of the ambient sound signal added to the input music signal by an additional 6 dB (an example of a second predetermined value) from 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 the wind noise is relatively low, as long as wind noise is detected, it is possible to adaptively reduce the wind noise included in the audio signal or music signal according to the wind conditions around the user U and the operating mode specified by the user U.

[0136] As described above, according to the headphones 1 (an example of earphones) of Embodiment 2, the headphones 1 worn by user U include: a plurality of microphones (an example of a sound-collecting unit) that collect ambient sounds around user U; a music playback / telephone mode switching unit 32 (an example of an input unit) that can input an audio signal from the smartphone P2 (an example of a terminal) of the person user U is talking to or a music signal for playback from 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 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) of a circuit board 20 that adjusts the characteristics of the ambient sound signal 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-emitting unit) that outputs an audio signal or music signal to which the adjusted ambient sound signal has been added.

[0137] Furthermore, according to the earphone control method of Embodiment 2, the earphone control method for headphones 1 (an example of earphones) worn by user U comprises the steps of: collecting ambient sounds of user U at multiple locations (sound collection step); enabling input of an audio signal from the smartphone P2 (an example of a terminal) of user U's call partner or a music signal for playback from user U's smartphone P1 (an example of a terminal) (input step); detecting the presence or absence of wind noise around user U based on the ambient sounds collected in the sound collection step (wind noise detection step); 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 step); and outputting the audio signal or music signal to which the adjusted ambient sound signal has been added (sound emission step).

[0138] As a result, according to the headphone 1 or earphone control method of Embodiment 2, even when the wind conditions around user U fluctuate, such as the strength of the wind or instantaneous changes in the wind, wind noise included in the audio signal or music signal can be adaptively reduced according to the wind conditions around user U and the operating mode specified by user U.

[0139] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 2, the ambient filter / 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 a set value when the wind noise level is above a predetermined value (-10 dBV). As a result, according to the headphones 1 or earphone control method of Embodiment 2, even when the ambient filter / volume adjustment unit 44 is set to ON when the wind noise is relatively high, the wind noise included in the audio signal or music signal can be adaptively reduced according to the wind conditions around the user U and the operating mode specified by the user U.

[0140] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 2, the ambient filter / 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 additional 6 dB (an example of a second predetermined value) from the set value when the wind noise level is less than a predetermined value (-10 dBV). As a result, according to the headphones 1 or earphone control method of Embodiment 2, even when the ambient filter / volume adjustment unit 44 is set to ON when the wind noise is relatively low, the wind noise included in the audio signal or music signal can be adaptively reduced according to 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 Embodiment 2, when a user U specifies that ambient sound signals should not be added to the audio signal or music signal, the ambient filter / 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 emission unit). As a result, according to the headphones 1 or earphone control method of Embodiment 2, when user U specifies that ambient sound signals should not be added to the audio signal or music signal, the operation of the ambient filter / volume adjustment unit 44 is set to off. Therefore, the input audio signal or music signal is output directly from the driver 10 without any ambient sound being added.

[0142] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 2, an internal microphone 8A (an example of a sound-receiving unit) that picks up sound-receiving signals from the audio signal or music signal output from the driver 10 (an example of a sound-emitting unit), and a feedback filter unit 48 (an example of a sound-receiving filter) that generates an inverse phase signal of the sound-receiving signal. The driver 10 also outputs a signal which is the sum of the audio signal or music signal, to which a characteristic-adjusted ambient sound signal has been added, and the inverse phase signal of the sound-receiving signal. As a result, according to the headphones 1 or earphone control method of Embodiment 2, ambient noise from the user U that cannot be physically suppressed by the ear pad 7 and that passes through the ear pad 7 into the acoustic space 11 of the headphones 1 can be actively removed. Therefore, the user U can hear a clearer audio signal or music signal.

[0143] (Embodiment 3) Embodiment 3 of this disclosure will be described based on Figures 9 and 10. Note that for parts that are the same as or equivalent to those described in Embodiments 1 and 2 above, the same reference numerals are used in the drawings, and their descriptions may be omitted or simplified to avoid repetition in the explanation.

[0144] [Regarding the process leading to Embodiment 3] First, I will explain the background leading to this embodiment.

[0145] In the configuration disclosed in Japanese Patent Publication No. 2015-219527, compensation is performed using a signal that includes acoustic noise components picked up by an internal microphone when the user is, for example, walking, thus enabling the reduction of acoustic noise signals included in the audio signal. However, the configuration disclosed in Japanese Patent Publication No. 2015-219527 does not assume that the reduction of noise or the addition of ambient sound to the audio headset will be appropriately controlled depending on the user's physical movements while wearing the audio headset. Therefore, when a user wearing the audio headset is walking or conversing with someone facing them, there was room for improvement in how the audio headset adaptively reduces noise signals such as breathing sounds, the user's voice, and pulse sounds emitted from within the user's body, as well as ambient sound, from the audio signal, or how ambient sound is incorporated into the audio signal.

[0146] In contrast, in this embodiment, depending on the physical movements or speech state of the user wearing the audio headset (in other words, headphones 1 as an example of earphones), the audio headset 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, from the audio signal, or incorporate ambient sounds into the audio signal.

[0147] [Regarding the circuit board configuration] Next, the configuration of the circuit board 20 will be described with reference to Figure 9. Figure 9 is a hardware block diagram illustrating the processing on the circuit board 20 of Embodiment 3.

[0148] In this embodiment, the case where headphones 1 are used for music playback rather than telephone use is described as one example, and as in Embodiment 2, the bandpass filter and volume control unit 31 do not operate in the main circuit 30. Similarly, in the ANC circuit 40, the sidetone filter unit 43, the feedforward filter unit 45, and the second digital summer unit 46B do not operate. Similarly, in the detection circuit 50, the speech detection unit 51, the beamform unit 53, and the wind noise detection unit 52 do not operate. Therefore, in Figure 9, the blocks representing these units and their associated signal lines are shown with dotted lines. However, it is possible to appropriately apply the disclosures of this embodiment even when headphones 1 are used for telephone use.

[0149] As shown in Figure 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 user U's smartphone P1 and determines that it is for music playback based on this reception result. The music playback / telephone mode switching unit 32 then switches the operating mode of the headphones 1 to music playback and transmits the music signal input to itself to the volume control unit 33. When the headphones 1 are used for telephone purposes, the music playback / telephone mode switching unit 32 will transmit the audio from the other party's smartphone P2.

[0150] The bone conduction sensor 9 of this embodiment (an example of a vibration detection unit, which is an example of a detection unit) detects vibrations based on the movements of user U. That is, as described above, the bone conduction sensor 9 is attached to the earphone so as to be able to contact the surface of the face around the ear or the back of the auricle, and detects vibrations of the human bone. Therefore, the bone conduction sensor 9 can detect not only vibrations associated with the voice spoken by user U, but also vibrations caused by the movement of user U's body.

[0151] The bone conduction sensor 9 transmits its detection result to the detection circuit 50 (an example of a control unit, which is a signal processing unit or an example of a control unit, which is a periodic sound determination unit) via the second analog-to-digital conversion unit 42B. If the bone conduction sensor 9 detects a periodic sound, it can be inferred that the user U is exercising, such as walking or running. Therefore, the detection circuit 50 determines whether or not a periodic sound is being generated based on the vibration detection result 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 vibration level to the ANC circuit 40.

[0152] The ambient filter / volume control 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 / volume control unit 44 performs predetermined audio processing on this audio signal and adjusts its volume level before transmitting it to the first digital summer unit 46A. The first digital summer unit adds the digital audio signal transmitted from the ambient filter / volume control unit 44 and the digital audio signal transmitted from the volume control unit 33 of the main circuit 30, and then transmits the result to the second digital summer unit 46B.

[0153] In this way, ambient sound picked up by the external microphone 8B is added to the audio signal from the smartphone P1. That is, in this embodiment, the ambient sound addition unit (an example of a control unit) is composed of the ambient filter / volume adjustment unit 44 and the first digital summing unit 46A.

[0154] Furthermore, the feedback filter unit 48 converts the analog signal based on the internal microphone 8A to an inverse phase to generate an inverse phase signal, which is output to the analog summer unit 49. The analog summer unit 49 adds the audio signal output from the digital-to-analog conversion unit 47 and the audio signal (inverse phase signal) output from the feedback filter unit 48 as an analog signal and outputs it to the fourth amplifier unit 41D.

[0155] In this way, the feedback filter unit 48 and the analog summer unit 49 reduce noise contained in the audio signal from the smartphone P1 based on the signal picked up by the internal microphone 8A after a portion of the audio signal output from the driver 10 has been fed back into it. In other words, in this embodiment, the feedback filter unit 48 and the analog summer unit 49 constitute a noise reduction unit (an example of a control unit).

[0156] In this embodiment, the ANC circuit 40 controls the operation of the ambient filter / volume adjustment unit 44 and the first digital summing unit 46A, which are ambient sound addition units, and the feedback filter unit 48 and the analog summing unit 49, which are noise reduction units, based on the determination result of the periodic sound.

[0157] [Regarding the processing flow on the circuit board] Next, the processing flow in the circuit board 20 according to this embodiment will be described with reference to Figure 10. Figure 10 is a flowchart illustrating the processing flow in the circuit board 20 shown in Figure 9.

[0158] As shown in Figure 10, the circuit board 20 determines whether the noise reduction units of the feedback filter unit 48 and the analog summer unit 49 are set to OFF (S301). If the determination result is that they are not set to OFF (NO in S301), the processing flow returns to step S301. In other words, the processing flow does not proceed to step S302 or beyond unless the noise reduction units of the feedback filter unit 48 and the analog summer unit 49 are set to OFF.

[0159] On the other hand, if it is determined that the feedback filter unit 48 and the noise reduction unit of the analog summing unit 49 are set to off, the bone conduction sensor 9 detects vibrations based on the movement of user U, and the detection circuit 50 receives the result of these vibrations (S302). The detection circuit 50 then determines whether or not a periodic sound is being generated based on the vibration detection result transmitted from the bone conduction sensor 9 (S303).

[0160] If the determination result indicates that a periodic sound is being generated (YES in S303), the detection circuit 50 detects the vibration level and determines whether the vibration level is above a predetermined value (-20 dBV) (S304). If the determination result indicates that the vibration level is above a predetermined value (-20 dBV) (YES in S304), the determination result is transmitted to the ANC circuit 40.

[0161] In this case, it is presumed that user U is performing strenuous exercise. Therefore, in order to reduce the noise in the acoustic space 11 associated with the strenuous exercise, the detection circuit 50 sets the operation of the noise reduction unit of the feedback filter unit 48 and the analog summer unit 49 to ON (S305) and returns to step S302. On the other hand, if the judgment result determines that the vibration level is less than a predetermined value (-20dBV) (NO in S304), the detection circuit 50 returns to step S302 without changing the operation settings of the noise reduction unit of the feedback filter unit 48 and the analog summer unit 49, that is, without doing anything.

[0162] If it is determined that no periodic sound is being generated (NO in S303), the circuit board 20 determines whether the ambient filter / volume adjustment unit 44 and the ambient sound addition unit of the first digital summer 46A are set to ON (S306). If it is determined that they are set to ON (YES in S306), the processing flow returns to step S302. In other words, the processing 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 summer 46A are set to OFF.

[0163] 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 summer 46A are set to OFF, the detection circuit 50 detects the vibration level and determines whether the vibration level is above a predetermined value (-40dBV) (S307). If the result of the determination is that the vibration level is above the predetermined value (-40dBV) (YES in S307), it is presumed that user U is speaking and conversing with the surroundings. 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 summer 46A to ON to correspond to this operating mode (S308) and returns to step S302. On the other hand, if it is determined that the vibration level is below the predetermined value (-40dBV) (NO in S307), the ANC circuit 40 keeps the operation setting of the ambient filter / volume adjustment unit 44 and the ambient sound addition unit of the first digital summer 46A OFF (S309) and returns to step S302.

[0164] In this way, the ANC circuit 40 controls the operation of the ambient sound addition section of the ambient filter / volume adjustment section 44 and the first digital summer section 46A, and the noise reduction section of the feedback filter section 48 and the analog summer section 49, respectively, based on the judgment result of the periodic sound. As a result, it becomes possible to adaptively reduce the noise signal contained in the music signal from the user's smartphone P1 and to take in ambient sound, depending on the user U's physical movement state or speech state.

[0165] As described above, according to the headphones 1 (an example of earphones) of Embodiment 3, the headphones 1 worn by user U include an external microphone 8B (an example of a first sound-collecting unit, which is an example of a sound-collecting unit) that picks up ambient sounds of user U, an input unit (e.g., a music playback / telephone mode switching unit 32) that receives music signals (audio signals; the same applies hereinafter) from user U's terminal (e.g., 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 user U's movements, and based on the vibration detection result, a periodic sound The system 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 sound is occurring, an ambient filter / volume adjustment unit 44 and a first digital summer 46A (an example of an ambient sound addition unit) that add ambient sound picked up by an external microphone 8B to the music signal from the smartphone P1, and an ANC circuit 40 on the circuit board 20 (an example of a signal processing unit, which is an example of a control unit) that causes the ambient sound addition unit of the ambient filter / volume adjustment unit 44 and the first digital summer 46A to be controlled differently based on the periodic sound determination result.

[0166] Furthermore, according to the headphones 1 (an example of earphones) of Embodiment 3, the headphones further include an internal microphone 8A (an example of a second sound-collecting unit, which is an example of a sound-collecting unit) positioned within the acoustic space 11 including the user U's auricle, a driver 10 (an example of a sound-emitting unit) that outputs a music signal from the user U's terminal (e.g., a smartphone P1), and a feedback filter unit 48 and an analog summing unit 49 (an example of a noise reduction unit) that reduce noise contained in the music signal from the smartphone P1 based on the signal picked up by a portion of the music signal output from the driver 10 that has leaked back to the internal microphone 8A. In addition, the ANC circuit 40 of the circuit board 20 (an example of a signal processing unit, which is an example of a control unit) controls the noise reduction unit of the feedback filter unit 48 and the analog summing unit 49 and the ambient sound addition unit of the ambient filter / volume adjustment unit 44 and the first digital summing unit 46A differently based on the determination result of periodic sound.

[0167] Furthermore, according to the earphone control method of Embodiment 3, the earphone control method for headphones 1 (an example of earphones) worn by user U comprises the steps of: collecting ambient sound of user U (sound collection step); inputting a music signal from user U's terminal (e.g., smartphone P1) (input step); detecting vibrations based on user U's movements (vibration detection step); determining whether or not a periodic sound is being generated based on the vibration detection result (periodic sound determination step); adding the ambient sound collected in the sound collection step to the music signal from smartphone P1 (ambient sound addition step); and differentiating the control when ambient sound is added based on the periodic sound determination result (signal processing step).

[0168] Therefore, depending on the user U's physical movements or speech state, it can adaptively reduce noise signals contained in the music signal from their smartphone P1 and incorporate ambient sounds.

[0169] Furthermore, according to the headphones 1 (earphones) of Embodiment 3, the headphones 1 worn by user U include an internal microphone 8A (an example of a first sound-collecting unit, which is an example of a sound-collecting unit) positioned in the acoustic space 11 including the auricle of user U, a driver 10 (an example of a sound-emitting unit) that outputs a music signal from user U's terminal (e.g., 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 user U's movements, 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 being generated based on the vibration detection result, a feedback filter unit 48 and an analog summing unit 49 (an example of a noise reduction unit) that reduce noise contained in the music signal from smartphone P1 based on the signal picked up by a part of the music signal output from driver 10 that has leaked back to the internal microphone 8A, and an ANC circuit 40 of a circuit board 20 (an example of a signal processing unit, which is an example of a control unit) that causes the control by the noise reduction unit of the feedback filter unit 48 and the analog summing unit 49 to differ based on the periodic sound determination result.

[0170] Furthermore, according to the headphones 1 (earphones) of Embodiment 3, an external microphone 8B (an example of a second sound pickup unit, which is an example of a sound pickup unit) that picks up ambient sounds around the user U, and an ambient filter / volume adjustment unit 44 and a first digital summing unit 46A (an example of an ambient sound addition unit) that add ambient sounds picked up by the external microphone 8B to the music signal from the terminal (e.g., smartphone P1). The ANC circuit 40 of the circuit board 20 (an example of a signal processing unit, which is an example of a control unit) controls the noise reduction unit of the feedback filter unit 48 and analog summing unit 49 and the ambient sound addition unit of the ambient filter / volume adjustment unit 44 and the first digital summing unit 46A respectively differently based on the determination result of periodic sound.

[0171] Furthermore, according to the earphone control method of Embodiment 3, the earphone control method for headphones 1 (an example of earphones) worn by user U comprises the steps of: collecting music in the acoustic space 11 using an internal microphone 8A (an example of a sound-collecting unit) placed in the acoustic space 11 including the auricle of user U (sound collection step); outputting a music signal from user U's smartphone P1 (an example of a terminal) (sound emission step); detecting vibrations based on user U's movements (vibration detection step); determining whether or not a periodic sound is being generated based on the vibration detection result (periodic sound determination step); reducing noise contained in the music signal from smartphone P1 based on the signal collected when a part of the music signal output in the sound emission step is passed back to the internal microphone 8A (noise reduction step); and differentiating the control during noise reduction based on the periodic sound determination result (signal processing step).

[0172] Therefore, depending on the user U's physical movements or speech state, it can adaptively reduce noise signals contained in the music signal from their smartphone P1 and incorporate ambient sounds.

[0173] Although several embodiments of the invention have been described above with reference to the drawings, it goes without saying that this disclosure is not limited to such examples. It is clear to those skilled in the art that various modifications, alterations, substitutions, additions, deletions, and equivalents can be conceived within the scope of the claims, and these are also understood to fall within the technical scope of this disclosure. Furthermore, the components of the embodiments described above can be combined in any way without departing from the spirit of the invention.

[0174] This application is based on Japanese patent applications filed on December 25, 2020 (Japanese Patent Application Nos. 2020-217010, 2020-217011, and 2020-217012), the contents of which are incorporated by reference in this application. [Industrial applicability]

[0175] This disclosure is useful for earphones and earphone control methods that can adaptively reduce noise signals such as breathing sounds, user voice, and pulse sounds emitted from within the user's body, as well as ambient sounds, or incorporate ambient sounds into the audio signal, depending on the physical movements or speech state of the user wearing the audio headset.

[0176] Furthermore, this disclosure is useful as an earphone and 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.

[0177] Furthermore, this disclosure is useful as an earphone and earphone control method that can adaptively adjust the characteristics of the user voice for transmission sent to the other party's terminal according to the state of wind noise that may occur during a call with the other party, thereby reducing wind noise contained in the user voice. [Explanation of Symbols]

[0178] 1 Headphones 2 headbands 3. Main body 4 Housing 5 Openings 6 partition plates 7 Ear pads 8A Internal Microphone 8B External Microphone 8C Speech Microphone 9 Bone conduction sensor 10 drivers 11 Acoustic Space 12 Storage Spaces 13. Mobile phone network 20 Circuit boards 30 Main Circuit 31 Bandpass filter and volume control section 32 Music Playback / Phone Mode Switching Section 33 Volume control section 40 ANC circuit 41A First Amplifier Section 41B Second Amplifier Section 41C Third Amplifier Section 41D Fourth Amplifier Section 42A First Analog-to-Digital Conversion Section 42B Second Analog-to-Digital Conversion Section 43 Side tone filter section 44 Ambient filter / volume control section 45 Feedforward filter section 46A First Digital Addition Unit 46B Second Digital Adding Unit 47 Digital-to-Analog Conversion Section 48 Feedback filter section 49 Analog Adding Section 50 Detection Circuit 51 Speech detection unit 52 Wind noise detection unit 53 Beamform Section

Claims

1. These are earphones that are worn by the user, Sound pickup section, A detection unit that detects the user's movements or the influence of the surroundings, The system comprises a control unit that processes the output sound based on the sound-collecting signal collected by the sound-collecting unit and the detection result by the detection unit, The sound-collecting unit comprises a plurality of sound-collecting units that collect ambient sounds around the user, The detection unit is A speech detection unit that detects whether or not the user is speaking, The system includes a wind noise detection unit that detects the presence or absence of wind noise around the user based on ambient sounds picked up by each of the plurality of sound-collecting units, The control unit, The system includes a signal processing unit that adjusts the characteristics of the audio signal based on the user's speech based on whether or not the user is speaking and the results of wind noise detection. Earphones.

2. The signal processing unit, when the level of the wind noise is above a predetermined value and the user's speech is detected, passes through the audio signal based on the user's speech that is in a first frequency band higher than the frequency band of the wind noise, and increases the volume level of the audio signal based on the user's speech by a first predetermined value. The earphones according to claim 1.

3. The signal processing unit, when the level of the wind noise is above a predetermined value and no user speech is detected, passes through an audio signal in a second frequency band that is higher in frequency than the frequency band of the wind noise from the ambient sound signal, and reduces the volume level of the ambient sound signal by a second predetermined value. The earphones according to claim 1.

4. The signal processing unit, when the level of the wind noise is below a predetermined value and the user's speech is detected, passes through the audio signal based on the user's speech that is in a third frequency band higher than the frequency band of the wind noise, and increases the volume level of the audio signal based on the user's speech by a third predetermined value. The earphones according to claim 1.

5. The signal processing unit, when the wind noise level is below a predetermined value and no user speech is detected, passes through the audio signal in the fourth frequency band, which is higher in frequency than the wind noise frequency band, and reduces the volume level of the ambient noise signal by a fourth predetermined value. The earphones according to claim 1.

6. A method for controlling earphones worn by a user, Steps for recording sound, The steps include detecting the user's movements or the influence of the surroundings, The system includes a step of processing the output sound based on the sound-collecting signal obtained in the sound-collecting step and the detection result obtained in the detection step, In the sound collection step, ambient sounds of the user are collected at multiple locations. In the step of detecting the user's movements or the influence of the surroundings, the presence or absence of speech from the user is detected, The step of processing the output sound is: The steps include detecting the presence or absence of wind noise around the user based on ambient sounds collected at the aforementioned multiple locations, The process includes the step of adjusting the characteristics of the audio signal based on the user's speech, based on whether or not the user has spoken and the results of detecting wind noise. How to control earphones.

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