Communication device, and communication control method thereof

Abstract

To provide a communication device capable of encouraging users of communication devices to speak at an appropriate volume.SOLUTION: A communication device 1 includes: a bone conduction microphone 11 that collects the voices of a user and that generates a transmitting signal; a receiver 12 that reproduces sounds based on received signals from an opposite device; a voice transmission line 22 that transmits signals from the bone conduction microphone 11 to the opposite device; a receiving transmission line 24 that transmits the received signal to a receiver 12; and a loopback circuit 25 is placed between the voice transmission line 22 and the receiving transmission line 24 to process the transmitting signals and synthesize the generated sidetone signals with the receive signals. The loopback circuit 25 operates based on any of multiple pre-prepared operating modes to control at least one of the on / off of sidetone and the level of sidetone reproduced by receiver 12 based on the sidetone signal.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a communication device that includes a bone conduction microphone and a receiver and is worn on a user's ear, head, or the like, and a communication control method thereof. [Background technology]

[0002] Conventionally, in telephones, a technology has been widely used to improve speech quality by outputting the user's voice picked up by the transmitter as a side tone from the receiver. When a user talks to a call partner, listening to the side tone output from the receiver makes it easier for the user to adjust the quality and clarity of the voice he or she produces.

[0003] Regarding the use of such side tones, for example, there is known a telephone set having a phase conversion circuit which converts the phase of an electrical audio signal sent from a transmitter and outputs a phase-converted output signal, a signal synthesis circuit which combines the phase-converted output signal with an audio signal in which the electrical audio signal of the other party and the electrical side tone signal are combined, thereby removing only the electrical side tone signal and extracting only the electrical audio signal of the other party, and a selection switch which selects whether or not to input the phase-converted output signal to the signal synthesis circuit (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 3-22451 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, communication devices have been developed that are inserted into the ears of users and have a housing that houses a bone conduction microphone that picks up the user's voice and an air conduction receiver that plays back the received voice of the other party. The bone conduction microphone used in communication devices is less susceptible to ambient noise than the air conduction microphone, and therefore has excellent sound pickup performance for relatively quiet voices.

[0006] As a result of intensive research, the inventors of the present application have found that in such a communication device equipped with a bone conduction microphone, the presence or absence of side sound and the level of the side sound can be controlled according to the user's speaking situation (i.e., the sound picked up by the bone conduction microphone), thereby encouraging the user to speak at an appropriate volume. By controlling the side sound in this way, the user can be made aware of insufficient speaking (i.e., the speaking level is too low) or excessive speaking (i.e., the speaking level is too high).

[0007] In contrast, in the conventional technology described in Patent Document 1, the side tone can be switched on and off by a selection switch, but no consideration is given at all to controlling the side tone in response to the user's voice.

[0008] Therefore, the main objective of the present disclosure is to provide a communication device and a call control method thereof that can encourage a user to speak at an appropriate volume by controlling the presence or absence of side tone and the level of the side tone depending on the user's speaking situation. [Means for solving the problem]

[0009] The communication device of the present disclosure comprises a bone conduction microphone that picks up the user's voice and generates a transmission signal, a receiver that reproduces sound based on a reception signal received from a partner device, a transmission path for transmitting the transmission signal from the bone conduction microphone to the partner device, a reception transmission path for transmitting the reception signal to the receiver, and a loopback circuit provided between the transmission path for transmitting and the reception transmission path for synthesizing a side tone signal generated by processing the transmission signal with the reception signal, wherein the loopback circuit operates based on one of a plurality of operating modes prepared in advance, thereby controlling at least one of turning on and off the side tone reproduced by the receiver based on the side tone signal and the level of the side tone.

[0010] The call control method disclosed herein is a call control method for a calling device, the calling device comprising a bone conduction microphone that picks up a user's voice and generates a transmission signal, a receiver that plays sound based on a reception signal received from a partner device, a transmission path for transmitting the transmission signal from the bone conduction microphone to the partner device, and a reception transmission path for transmitting the reception signal to the receiver, the calling device being capable of synthesizing a side tone signal generated by processing the transmission signal with the reception signal, and configured to control at least one of turning on and off the side tone reproduced by the receiver based on the side tone signal and the level of the side tone based on one of a plurality of operating modes prepared in advance. Effect of the Invention

[0011] According to the present disclosure, by controlling the presence or absence of side tone and the level of the side tone depending on the speaking state of the user of the communication device, it is possible to encourage the user to speak at an appropriate volume. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view showing a state in which a communication device according to a first embodiment is used; [Diagram 2] FIG. 2 is an exploded perspective view of the earphone shown in FIG. 1. [Diagram 3] A functional block diagram showing the configuration of a communication device according to a first embodiment. [Figure 4] FIG. 1 is an explanatory diagram showing the output characteristics of sidetone in each operation mode ((A) low voice adaptation mode, (B) high voice suppression mode, (C) mix mode) of a communication device according to a first embodiment. [Diagram 5] FIG. 11 is an explanatory diagram showing an example of a setting screen for an operation mode of the communication device according to the first embodiment; [Figure 6] FIG. 4 is a functional block diagram showing a first modified example of the configuration of the communication device shown in FIG. 3. [Figure 7] FIG. 4 is a functional block diagram showing a second modified example of the configuration of the communication device shown in FIG. 3. [Figure 8] A functional block diagram showing the configuration of a communication device according to a second embodiment. [Figure 9]FIG. 11 is an explanatory diagram showing side tone characteristics in each operation mode ((A) low voice adaptation mode, (B) high voice suppression mode, (C) mixed mode) of a communication device according to a second embodiment. [Figure 10] FIG. 9 is a functional block diagram showing a first modified example of the configuration of the communication device shown in FIG. 8. [Figure 11] FIG. 10 is an explanatory diagram showing the comfort zone and the discomfort zone in the relationship between the amount of sidetone delay and the sidetone playback volume. [Figure 12] FIG. 9 is a functional block diagram showing a second modified example of the configuration of the communication device shown in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The first invention made to solve the above problem is a call control method for a telephone device, the telephone device comprising a bone conduction microphone that picks up a user's voice and generates a transmission signal, a receiver that reproduces sound based on a reception signal received from a counterpart device, a transmission path for transmitting the transmission signal from the bone conduction microphone to the counterpart device, and a reception transmission path for transmitting the reception signal to the receiver, the telephone device being capable of synthesizing a side tone signal generated by processing the transmission signal with the reception signal, and configured to control at least one of turning on and off the side tone reproduced by the receiver based on the side tone signal and the level of the side tone based on one of a plurality of operating modes prepared in advance.

[0014] This allows the user to be encouraged to speak at an appropriate volume by using multiple operating modes to control the presence or absence (i.e., on / off) of side tone and the level of side tone according to the user's speaking situation.

[0015] In addition, the second invention is configured such that the multiple operating modes include a low-voice adaptation mode, and in the low-voice adaptation mode, the side sound is disabled only when the level of the sound picked up by the bone conduction microphone is equal to or lower than a first threshold value.

[0016] According to this, when the level of the sound picked up by the bone conduction microphone is below a first threshold (i.e., the user's speaking volume is insufficient), the side sound is disabled (i.e., the side sound is turned off or the side sound level is set to essentially zero) to notify the user that the speaking volume is insufficient, thereby encouraging the user to speak at an appropriate volume.

[0017] In addition, a third invention is configured such that the multiple operating modes include a loud voice suppression mode, and in the loud voice suppression mode, the level of the side sound is increased when the level is equal to or greater than a second threshold value that is greater than the first threshold value.

[0018] According to this, when the level of the sound picked up by the bone conduction microphone is equal to or higher than the second threshold (i.e., the user's speaking volume is excessive), the side sound level is increased to inhibit the user's speaking, thereby encouraging the user to speak at an appropriate volume.

[0019] In a fourth aspect of the present invention, the loopback circuit includes a microphone sound detector that detects the level of sound picked up by the bone conduction microphone based on the transmission signal from the transmission path for transmission of voice.

[0020] This allows a plurality of operation modes to be appropriately executed based on the level of the sound picked up by the bone conduction microphone.

[0021] In addition, a fifth aspect of the present invention is configured to further include an input device through which the user performs an input operation, and the plurality of operation modes are turned on and off individually based on the user's input operation on the input device.

[0022] This allows the user to easily select a desired operation mode and have the telephone device execute that operation mode.

[0023] In a sixth aspect of the present invention, the loopback circuit includes a gain adjustment section that adjusts a gain for the transmission signal from the transmission path for voice transmission.

[0024] According to this, by appropriately adjusting the gain of the transmission signal as the processing for the transmission signal, the side tone based on the generated side tone signal can be appropriately reproduced by the receiver.

[0025] In addition, the seventh invention further includes an ambient sound detector that detects the level of ambient sound, excluding the user's voice, picked up by the bone conduction microphone based on the transmission signal from the transmission path for talking, and the gain adjustment unit is configured to adjust the gain for the transmission signal from the transmission path for talking based on the level of the ambient sound.

[0026] According to this, the gain for the transmission signal is appropriately adjusted based on the level of the ambient sound (excluding the user's voice) picked up by the bone conduction microphone, so that the side sound can be appropriately reproduced by the receiver.

[0027] In addition, the eighth invention is configured to further include a volume adjustment unit provided in the receiving transmission path for adjusting the volume of the sound based on the receiving signal reproduced by the receiver based on the receiving signal, and the gain adjustment unit sets the gain based on the degree of adjustment of the volume by the volume adjustment unit.

[0028] According to this, by appropriately setting the gain for the transmission signal based on the degree of volume adjustment by the volume adjustment unit, the side tone can be appropriately reproduced by the receiver.

[0029] In addition, in a ninth aspect of the present invention, the loopback circuit further includes a speech detector which detects whether or not the user is speaking based on the transmission signal from the transmission path for speaking, and is configured to execute the low voice adaptation mode when it is determined based on the detection result of the speech detector that the sound picked up by the bone conduction microphone does not include any speech by the user at or above a predetermined level.

[0030] This allows the low voice adaptation mode to be appropriately executed when the sound picked up by the bone conduction microphone does not include the user's vocalization at a specified level (i.e., when the user speaks but the volume is insufficient).

[0031] In addition, in a tenth aspect of the present invention, the loop-back circuit includes a voice extraction unit that extracts a voice signal based on the user's voice from the transmission signal from the transmission path for voice transmission, and generates the side tone signal based on the voice signal.

[0032] This makes it possible to appropriately generate a side tone signal (that is, improve the quality of the side tone reproduced by the receiver) based on the voice signal extracted from the transmitted signal.

[0033] In addition, an eleventh aspect of the present invention is configured such that the loopback circuit includes a delay processing unit that delays the audio signal based on a predetermined delay time in the loud voice suppression mode, and generates the side tone signal based on the delayed audio signal.

[0034] This allows the timing of the side sound reproduced by the receiver to be delayed by the side sound signal generated based on the delayed audio signal (i.e., giving the user a feeling of discomfort and preventing loud speech), thereby encouraging the user to speak at an appropriate volume.

[0035] In addition, the twelfth invention is a configuration further comprising a noise canceller provided in each of the transmission paths for transmitting voice, which removes or reduces noise components in the transmitting signal that is the subject of processing by the loopback circuit, and an echo canceller which removes or reduces echo components included in the transmitting signal that is the subject of processing by the loopback circuit.

[0036] According to this, the noise component and the echo component are removed from the transmission signal, so that the side tone signal can be generated appropriately (that is, the quality of the side tone reproduced by the receiver can be improved).

[0037] In a thirteenth aspect of the present invention, the loopback circuit includes a band expanding section that expands the frequency band of the sidetone signal.

[0038] This allows the sidetone signal to be generated appropriately (i.e., the quality of the sidetone reproduced by the receiver is improved) by band-expanding the audio signal.

[0039] In addition, a fourteenth invention is a call control method for a telephone device, the telephone device comprising a bone conduction microphone that picks up a user's voice and generates a transmission signal, a receiver that reproduces sound based on a reception signal received from a counterpart device, a transmission path for transmitting the transmission signal from the bone conduction microphone to the counterpart device, and a reception transmission path for transmitting the reception signal to the receiver, the telephone device being capable of synthesizing a side tone signal generated by processing the transmission signal with the reception signal, and configured to control at least one of turning on and off the side tone reproduced by the receiver based on the side tone signal and the level of the side tone based on any one of a plurality of operating modes prepared in advance.

[0040] This allows the user to be encouraged to speak at an appropriate volume by using multiple operating modes to control the presence or absence (i.e., on / off) of side tone and the level of side tone according to the user's speaking situation.

[0041] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0042] (First embodiment) Fig. 1 is a perspective view showing a communication device 1 according to a first embodiment of the present disclosure in use. Fig. 2 is an exploded perspective view of the earphone 2 shown in Fig. 1.

[0043] As shown in Fig. 1, the communication device 1 includes an earphone 2 constituting the communication device main body, and a signal processing device 3 that performs signal processing necessary for communication. Here, an example is shown in which the earphone 2 is inserted into the right ear 5 of the user. However, the earphone 2 may also be inserted into the left ear of the user. The communication device 1 may also include a pair of earphones 2, one on the left and one on the right.

[0044] In the communication device 1, the signal processing device 3 is connected to the earphone 2 via a signal line 4. However, the earphone 2 and the signal processing device 3 may be connected to each other so as to be able to communicate with each other via a wireless signal based on Wifi (registered trademark), Bluetooth (registered trademark), or the like.

[0045] Moreover, the earphone 2 may further include the same function as the signal processing device 3. That is, in the communication device 1, the signal processing device 3 may be configured to be integrated inside the housing of the earphone 2.

[0046] As shown in FIG. 2, the earphone 2 includes an exterior housing 9, a bone conduction microphone 11 housed in the exterior housing 9, an air conduction receiver 12, an internal housing 13, and a microphone rubber 15.

[0047] The exterior housing 9 constitutes the outer shell of the earphone 2. The exterior housing 9 includes a case 9A that constitutes the inner part (deeper part) of the user's ear, and a cover 9B that constitutes the outer part of the user's ear. The exterior housing 9 is constituted by overlapping the cover 9B on the case 9A from the outside. The exterior housing 9 is provided with a cable cap 10 for leading the signal line 4 to the outside.

[0048] The bone-conduction microphone 11 is a device provided at the ear of a user so as to mainly collect vocal cord vibrations transmitted to the vocal cord vibration transmission site, and collects the user's voice and ambient sounds generated around the user. The bone-conduction microphone 11 includes an element (e.g., a vibration detection element) for converting voice vibrations into an electric signal (one example of a transmission signal). In other words, the bone-conduction microphone 11 can collect sounds such as the user's voice and generate an electric signal. The electric signal generated by the bone-conduction microphone 11 is input to the signal processing device 3 via the signal line 4. The bone-conduction microphone 11 collects vocal cord vibrations propagating inside the user's body, and therefore has the property of being less susceptible to the influence of ambient sounds other than the user's voice.

[0049] The air conduction receiver 12 converts an electrical signal (an example of a received signal) input from the signal processing device 3 via the signal line 4 into a sound such as the speech of the other party and outputs the converted sound. The air conduction receiver 12 may be configured with a known speaker. A bone conduction receiver (bone conduction receiver) may be used instead of the air conduction receiver 12. For example, when the signal processing device 3 outputs an electrical signal corresponding to the speech of the other party, the air conduction receiver 12 outputs a sound corresponding to the speech of the other party. The sound output by the air conduction receiver 12 is not limited to the speech of the other party, and may include, for example, ambient sounds and on-hold sounds.

[0050] The internal housing 13 is a member for guiding the reproduced sound of the air conduction receiver 12 to the ear canal, and is provided with a passage 13A for guiding the reproduced sound of the air conduction receiver 12 to the ear canal. The air conduction receiver 12 is disposed on one end side of the passage 13A of the internal housing 13.

[0051] At the other end of the passage 13A, a cylindrical tube portion 13B is provided that extends to the outside of the exterior housing 9 through an opening 9C provided in the exterior housing 9 (specifically, the case 9A). In this embodiment, a tip rubber 16 that abuts against the user's ear canal over its entire circumference is provided at the extending end of the tube portion 13B. By having the tip rubber 16 abut against the ear canal over its entire circumference, airtightness of the ear canal is ensured, and the reproduced sound from the air conduction receiver 12 is effectively transmitted to the user.

[0052] The microphone rubber 15 elastically holds the bone-conduction microphone 11. The microphone rubber 15 connects the bone-conduction microphone 11 to a part where vocal cord vibration is transmitted via bones near the ear 5 (hereinafter referred to as vocal cord vibration transmission part). As a result, vocal cord vibration transmitted to the vocal cord vibration transmission part is transmitted to the bone-conduction microphone 11, and the bone-conduction microphone 11 picks up sound by detecting the vocal cord vibration propagating to the bones and skin around the ear via the microphone rubber 15.

[0053] The signal processing device 3 generates a signal to be output to a communication device of the other party (not shown) (one example of the other party's device). Based on the characteristics of the bone conduction microphone 11, the signal processing device 3 can increase the clarity of the user's voice while suppressing the influence of ambient sounds, and deliver the voice to the other party's communication device.

[0054] The communication device of the other party is not particularly limited, but may have the same configuration as the communication device 1. For example, in the communication device of the other party, based on the signal received from the communication device 1 of the user (i.e., the signal generated by the signal processing device 3), the voice of the user is output from an air conduction receiver built into the earphone, various speakers, etc.

[0055] The signal processing device 3 is configured by a terminal (e.g., a smartphone) equipped with a processor such as a CPU, a memory such as a RAM or a ROM, a storage such as an SSD or an HDD, a display such as a touch panel, a network interface, and an audio input / output terminal. However, the configuration of the signal processing device 3 is not limited to this embodiment, and may be configured by, for example, a tablet or various computers equipped with an audio input / output terminal. Furthermore, the signal processing device 3 may be realized by a combination of a logic device and various analog devices.

[0056] As described below, when a user talks to a call partner, the communication device 1 can output a side tone (i.e., the user's voice) from the air conduction receiver 12. The communication device 1 can encourage the user to speak at an appropriate volume by controlling the presence or absence (i.e., on / off) of the side tone and the level (sound pressure level) of the side tone according to the user's voice production situation.

[0057] Fig. 3 is a functional block diagram showing the configuration of the communication device 1 according to the first embodiment. Fig. 4 is an explanatory diagram showing the output characteristics of sidetone in each operation mode ((A) low voice adaptation mode, (B) loud voice suppression mode, (C) mix mode) of the communication device 1. Fig. 5 is an explanatory diagram showing an example of a setting screen for the operation mode of the communication device 1.

[0058] 3, in the communication device 1, an electrical signal (hereinafter referred to as a "transmitting signal") generated by the bone conduction microphone 11 is input to the signal processing device 3 via a signal line 4. The signal processing device 3 also outputs an electrical signal (hereinafter referred to as a "receiving signal") received from a partner device to the air conduction receiver 12 via the signal line 4. Although not shown in the figure, the signal processing device 3 may include an AD converter that converts the transmitting signal input from the bone conduction microphone 11 into a digital signal, and a DA converter that converts the receiving signal output to the air conduction receiver 12 into an analog signal.

[0059] The signal processing device 3 has a transmission path for sending 22 that transmits a transmission signal from the bone conduction microphone 11 toward the transmitting unit 21 (i.e., toward the other device). The signal processing device 3 also has a reception path for sending a reception signal from the receiving unit 23 (i.e., from the other device) toward the air conduction receiver 12. The signal processing device 3 also has a loopback circuit 25 provided between the transmission path for sending 22 and the reception path for receiving 24. The loopback circuit 25 processes the transmission signal from the transmission path for sending 22 to generate a side tone signal. The side tone signal is transmitted via a side tone transmission path 27 that connects the transmission path for sending 22 and the reception transmission path 24, and is combined with the reception signal of the reception transmission path 24.

[0060] The transmitting unit 21 and the receiving unit 23 may be configured with an antenna and a communication circuit for wireless communication with a partner device. The transmitting unit 21 transmits a transmission signal from the bone conduction microphone 11, transmitted through a transmission line for transmission of a voice, 22, to the partner device. The receiving unit 23 receives a reception signal transmitted from the partner device. The received reception signal is transmitted to the air conduction receiver 12 through a transmission line for reception of a voice 24.

[0061] In the signal processing device 3, the transmission path for talking 22 is provided with an amplifier 31 that amplifies the transmission signal. The transmission path for talking 24 is provided with a synthesis unit 33 that synthesizes (or superimposes) the side tone signal from the loopback circuit 25 with the reception signal from the reception unit 23, and an amplifier 35 that amplifies the reception signal with which the side tone signal has been synthesized. The amplifiers 31, 35 and the synthesis unit 33 may each be configured with an electronic element or circuit.

[0062] The loop-back circuit 25 includes a gain adjustment unit 36 ​​, a switch unit 37 , a first sound detector 38 , and a controller 39 .

[0063] The gain adjustment unit 36 ​​is provided in the sidetone transmission path 27, and generates a sidetone signal by adjusting the gain applied to the transmission signal from the transmission path 22 for transmitting voice (one example of processing of the transmission signal). At this time, the level of the sidetone based on the sidetone signal (i.e., the level of the sidetone reproduced by the air conduction receiver 12) is adjusted by the gain applied to the transmission signal. The gain adjustment unit 36 ​​can perform gain adjustment in different modes according to the operation mode executed by the communication device 1 described later.

[0064] The switch unit 37 is provided in the sidetone transmission path 27, and includes a switch capable of switching the sidetone signal from the gain adjustment unit 36 ​​on and off. When the switch unit 37 turns the sidetone signal on, the sidetone signal is input to the synthesis unit 33. The sidetone signal input to the synthesis unit 33 is synthesized with the received signal from the receiving unit 23, amplified by the amplification unit 35, and then reproduced by the air conduction receiver 12. On the other hand, when the switch unit 37 turns the sidetone off, the sidetone signal input to the synthesis unit 33 is blocked. As a result, the sidetone is not reproduced in the air conduction receiver 12, and only the sound from the other device (the voice of the other party and ambient sounds) is reproduced.

[0065] The first sound detector 38 (an example of a microphone sound detector) acquires the transmission signal transmitted through the transmission path 22 for transmitting voice, and can detect the level (dB) of the sound picked up by the bone conduction microphone 11 based on the transmission signal.

[0066] The controller 39 obtains a detection result from the first sound detector 38, and controls the on / off operation of the switch unit 37 based on the detection result. For example, the controller 39 can compare the level of the sound detected by the first sound detector 38 with one or more preset threshold values, and control the on / off operation of the switch unit 37 based on the comparison result. The controller 39 can execute different types of control according to the operation mode executed by the communication device 1, which will be described later.

[0067] The first sound detector 38 (an example of a speech detector) may detect the presence or absence of the user's speech (i.e., speech and silence) based on the speech signal instead of detecting the level of the sound collected by the bone-conduction microphone 11. Such detection of the presence or absence of the user's speech at a predetermined level can be performed, for example, by detecting the intensity of the voice signal and comparing it with a predetermined threshold (an example of a first threshold). Furthermore, the controller 39 can determine, for example, based on the detection result of the first sound detector 38, whether the user's speech at a predetermined level has been detected, and control the switch unit 37 to turn on the side tone signal when the user's speech is detected. On the other hand, the controller 39 can control the switch unit 37 to turn off the side tone signal when the user's speech at a predetermined level is not detected.

[0068] As hardware for configuring each component of the loopback circuit 25, a publicly known processor or electronic circuit can be used.

[0069] Next, a description will be given of a plurality of operation modes (including a low voice adaptation mode, a high voice suppression mode, and a mix mode) prepared in advance in the communication device 1. The communication device 1 can control at least one of the side tone on / off and the level of the side tone reproduced by the air conduction receiver 12 based on any of the operation modes.

[0070] In the soft voice adaptation mode, when the user's voice picked up by the bone conduction microphone 11 is insufficient (i.e., when the voice level is relatively low), the communication device 1 substantially disables the side tone reproduced by the air conduction receiver 12 (i.e., turns off the side tone or makes the side tone level substantially zero). This allows the communication device 1 to notify the user who can no longer hear the side tone that the voice volume is insufficient, thereby encouraging the user to speak at an appropriate volume (i.e., encourage louder voice).

[0071] In the soft voice adaptation mode, the controller 39 controls the operation of the switch unit 37 to turn off the side sound (one example of disabling the side sound) only when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Va1 (dB) (one example of a first threshold value) based on the detection result of the first sound detector 38. As a result, as shown in Fig. 4(A), when the level of the sound picked up by the bone conduction microphone 11 (see the horizontal axis) is equal to or lower than Va1 (dB), the level of the side sound output from the air conduction receiver 12 (see the vertical axis) is set to substantially zero (i.e., zero or a very small value).

[0072] On the other hand, when the level of the sound picked up by the bone conduction microphone 11 exceeds Va1 (dB), the controller 39 controls the operation of the switch unit 37 to turn on the side sound. As a result, a side sound of a predetermined level is output from the air conduction receiver 12, as shown in FIG. 4(A).

[0073] Here, in FIG. 4(A), the dashed line L indicates the standard output characteristic of the side tone based on the standard gain adjustment performed by the gain adjustment unit 36 ​​(similarly in FIG. 4(B) and (C)). In the low voice adaptation mode, when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Va2 (dB), the gain adjustment unit 36 ​​performs gain adjustment so as to attenuate the side tone signal. As a result, the level of the side tone output from the air conduction receiver 12 is reduced by a certain amount from the standard output level (see dashed line L). On the other hand, when the level of the sound picked up by the bone conduction microphone 11 exceeds Va2 (dB), the gain adjustment unit 36 ​​performs gain adjustment so as to maintain the level of the side tone at the sound level Va2 as it is (i.e., to keep the output of the side tone constant).

[0074] For example, the low voice adaptation mode allows the user to know how much speech is appropriate in a call environment where it is preferable to talk in a low voice, such as a place where there are other people around (for example, on a train or other public transport), etc. The low voice adaptation mode also allows the user to know how much speech is appropriate in a call environment where the surrounding noise is loud (a situation where it is difficult to recognize the user's own voice).

[0075] In the loud voice suppression mode, when the user's voice picked up by the bone conduction microphone 11 is excessively loud (i.e., when the voice volume level is relatively high), the communication device 1 increases the level of the side tone reproduced by the air conduction receiver 12 (i.e., outputs a side tone louder than the standard). This allows the communication device 1 to inhibit the user's voice with the side tone, and encourage the user to speak at an appropriate volume (i.e., encourage the user to suppress the voice volume).

[0076] In the loud voice suppression mode, the controller 39 controls the operation of the switch unit 37 to turn off the side sound only when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Vb1 (dB) (an example of a second threshold value) based on the detection result of the first sound detector 38. As a result, as shown in Fig. 4(B), when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Vb1 (dB), the level of the side sound output from the air conduction receiver 12 is set to substantially zero (i.e., zero or a very small value).

[0077] On the other hand, when the level of the sound picked up by the bone conduction microphone 11 exceeds Vb1 (dB), the controller 39 controls the operation of the switch unit 37 to turn on the side sound. As a result, a side sound of a predetermined level is output from the air conduction receiver 12, as shown in FIG. 4(B).

[0078] In the loud voice suppression mode, the gain adjustment unit 36 ​​performs gain adjustment to amplify the side sound signal, and increases the level of the side sound output from the air conduction receiver 12 by a certain amount from the standard output level (see dashed line L). As a result, when the level of the sound picked up by the bone conduction microphone 11 is equal to or higher than Vb1 (dB), the air conduction receiver 12 outputs a side sound at a level higher than the standard.

[0079] In the mixed mode, the communication device 1 selectively executes (i.e., uses both) the quiet voice adaptation mode and the loud voice suppression mode according to the user's speaking situation (i.e., the level of the speaking volume). In the mixed mode, the communication device 1 executes the quiet voice adaptation mode when the level of the sound picked up by the bone-conduction microphone 11 is less than Vb1 (dB), as shown in Fig. 4(C). Also, in the mixed mode, the communication device 1 executes the loud voice suppression mode when the level of the sound picked up by the bone-conduction microphone 11 is equal to or greater than Vb1 (dB).

[0080] A user of the communication device 1 can select a desired operation mode when starting a call with a call partner. For example, as shown in FIG. 5, the user can perform an operation to select a desired operation mode (low voice adaptation mode in this case) on an operation mode setting screen 41 displayed on a touch panel 40 (one example of an input device) of the signal processing device 3. The user can also select to turn off the operation mode (i.e., not to execute any operation mode). In addition, the communication device 1 may automatically select an operation mode regardless of the user's selection.

[0081] In this way, the communication device 1 can encourage the user to speak at an appropriate volume by using a plurality of operation modes to control the presence or absence (i.e., on / off) of sidetone and the level of the sidetone (i.e., adjusting the gain) according to the user's speaking situation. Note that, for example, as shown in Fig. 5, the communication device 1 may display an explanation of each operation mode on a display or the like so that the user can understand the purpose of selecting each operation mode.

[0082] The method of selecting each operation mode in the communication device 1 is not limited to the example of the operation mode setting screen 41 shown in FIG. 5. For example, as a modified example of the setting screen 41, only two items, the low voice adaptation mode and the high voice self-restraint mode, may be displayed, and the user may turn on and off these two items individually. In this case, the user substantially selects the "mixed mode" shown in FIG. 5 by performing an operation to turn on both the low voice adaptation mode and the high voice self-restraint mode. Furthermore, the user substantially selects the "off" shown in FIG. 5 by performing an operation to turn off both the low voice adaptation mode and the high voice self-restraint mode. Furthermore, the selection of each operation mode by the user is not limited to the operation of the touch panel 40, and may be performed by the user operating other known input devices (operation buttons, keyboards, etc.).

[0083] Fig. 6 is a functional block diagram showing a first modified example of the configuration of the communication device 1 shown in Fig. 3. In the first modified example shown in Fig. 6, the same components as those of the communication device 1 shown in Fig. 3 are given the same reference numerals. In addition, with regard to the first modified example, matters that are not particularly mentioned below are the same as those of the communication device 1 according to the above-mentioned first embodiment.

[0084] 6, in the first modification, the loopback circuit 25 of the signal processing device 3 further includes a second sound detector 48 (an example of an ambient sound detector). The second sound detector 48 acquires a transmission signal from the transmission line 22 for voice transmission, and can detect the level (dB) of the ambient sound, excluding the user's voice, picked up by the bone-conduction microphone 11, based on the transmission signal.

[0085] The gain adjustment unit 36 ​​acquires the detection result from the second sound detector 48, and based on the detection result, can finely adjust (i.e., correct) the gain applied to the transmission signal from the transmission path for voice transmission 22. For example, the gain adjustment unit 36 ​​can compare the level of the ambient sound detected by the second sound detector 48 with a predetermined threshold, and increase the gain from the initial value if the level of the ambient sound exceeds the threshold.

[0086] Fig. 7 is a functional block diagram showing a second modified example of the configuration of the communication device 1 shown in Fig. 3. In the second modified example shown in Fig. 7, the same components as those of the communication device 1 shown in Fig. 3 and Fig. 6 are given the same reference numerals. In addition, with regard to the second modified example, matters not specifically mentioned below are the same as those of the communication device 1 according to the above-mentioned first embodiment or its first modified example.

[0087] 7, in the second modification, a volume adjustment unit 51 is provided upstream of the synthesis unit 33 in the receiving transmission path 24. The volume adjustment unit 51 can adjust the gain applied to the received signal from the receiving unit 23, thereby adjusting the volume of the sound based on the received signal.

[0088] The gain adjustment unit 36 ​​acquires information on the gain applied to the received signal (one example of the degree of volume adjustment) from the volume adjustment unit 51. The gain adjustment unit 36 ​​can further fine-adjust (i.e., correct) the gain fine-adjusted according to the level of the ambient sound detected by the second sound detector 48 as described above, based on the gain information from the volume adjustment unit 51. For example, the gain adjustment unit 36 ​​can adjust the gain applied to the transmission signal from the transmission line 22 for voice transmission so as to be linked with the adjustment of the gain applied to the received signal (i.e., amplification or attenuation of the received signal). As a result, for example, when the level of the sound (i.e., sound other than the side tone) of the voice of the other party reproduced by the air conduction receiver 12 becomes large, the level of the side tone becomes large so as to correspond to the level of that sound. The gain adjustment unit 36 ​​may fine-adjust the gain applied to the transmission signal based on either the detection result from the second sound detector 48 or the gain information from the volume adjustment unit 51.

[0089] Second embodiment FIG. 8 is a functional block diagram showing the configuration of the communication device 1 according to the second embodiment. FIG. 9 is an explanatory diagram showing the output characteristics of the side tone in each operation mode ((A) low voice adaptation mode, (B) loud voice suppression mode, (C) mixed mode) of the communication device 1 according to the second embodiment. In the communication device 1 shown in FIG. 8, the same components as those in the communication device 1 according to the first embodiment (including the first and second modified examples) described above are given the same reference numerals. Furthermore, matters regarding the communication device 1 according to the second embodiment that are not specifically mentioned below are similar to those in the communication device 1 according to the first embodiment described above.

[0090] As shown in FIG. 8, in the communication device 1 according to the second embodiment, the loopback circuit 25 has a gain adjustment unit 36 ​​and an auto gain controller (hereinafter referred to as "AGC") 55. The AGC 55 can function in the same manner as the switch unit 37, the first sound detector 38, and the controller 39 of the communication device 1 according to the first embodiment. The AGC 55 can control the level of the side tone reproduced by the air conduction receiver 12 by controlling the gain applied to the side tone signal. For example, the AGC 55 can substantially block the side tone signal input to the synthesis unit 33 (i.e., substantially turn off the side tone) by controlling the gain applied to the side tone signal from the gain adjustment unit 36 ​​(one example of disabling the side tone). The gain control applied to the side tone signal by the AGC 55 can be executed according to the level of the sound picked up by the bone conduction microphone 11.

[0091] In the soft voice adaptation mode, the AGC 55 adds gain to the side tone signal to turn off the side tone (i.e., to attenuate the side tone signal) only when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Va1' (dB) (an example of a first threshold value). As a result, as shown in Fig. 9(A), when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Va1' (dB), the level of the side tone output from the air conduction receiver 12 is set to substantially zero.

[0092] When the level of the sound picked up by the bone-conduction microphone 11 exceeds Va1' (dB) and is equal to or lower than Va1 (dB), the AGC 55 controls the gain applied to the side tone signal so as to gradually suppress the attenuation of the side tone signal (i.e., to approach the standard output level). When the level of the sound picked up by the bone-conduction microphone 11 exceeds Va1' (dB) and is equal to or lower than Va2 (dB), the AGC 55 stops controlling the gain. When the level of the sound picked up by the bone-conduction microphone 11 exceeds Va2 (dB), the AGC 55 controls the gain so as to maintain the level of the side tone at the sound level Va2.

[0093] In the loud voice suppression mode, the AGC 55 adds gain to the side tone signal to turn off the side tone (i.e., to attenuate the side tone signal) only when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Vb1' (dB) (an example of a second threshold value). As a result, as shown in Fig. 9(B), when the level of the sound picked up by the bone conduction microphone 11 is equal to or lower than Vb1' (dB), the level of the side tone output from the air conduction receiver 12 is set to substantially zero.

[0094] When the level of the sound picked up by the bone-conduction microphone 11 exceeds Vb1' (dB) and is equal to or lower than Vb1 (dB), the AGC 55 controls the gain applied to the sidetone signal so as to gradually suppress the attenuation of the sidetone signal (i.e., to approach the standard output level). Also, when the sound level exceeds Vb1 (dB), the AGC 55 stops the gain control.

[0095] In the loud voice suppression mode, the gain adjustment unit 36 ​​performs gain adjustment to amplify the side sound signal, and increases the level of the side sound output from the air conduction receiver 12 by a certain amount from the standard output level (see dashed line L). As a result, when the level of the sound picked up by the bone conduction microphone 11 is equal to or higher than Vb1 (dB), the air conduction receiver 12 outputs a side sound at a level higher than the standard.

[0096] In the mixed mode, the communication device 1 selectively executes a low voice adaptation mode or a high voice suppression mode according to the user's speaking situation. In the mixed mode, the communication device 1 executes the low voice adaptation mode when the level of the sound picked up by the bone-conduction microphone 11 is less than Vb1' (dB) as shown in Fig. 9(C). In the mixed mode, the communication device 1 executes the high voice suppression mode when the level of the sound picked up by the bone-conduction microphone 11 is equal to or greater than Vb1' (dB).

[0097] Fig. 10 is a functional block diagram showing a first modified example of the configuration of the communication device 1 shown in Fig. 8. Fig. 11 is an explanatory diagram showing a comfort zone and an discomfort zone in the relationship between the side tone delay amount and the side tone reproduction volume. In the first modified example shown in Fig. 10, the same components as those in the communication device 1 shown in Fig. 8 are given the same reference numerals. Also, with regard to the first modified example, matters that are not particularly mentioned below are the same as those in the communication device 1 according to the above-mentioned second embodiment.

[0098] As shown in FIG. 10, in the first modified example, the loopback circuit 25 of the signal processing device 3 further includes a voice extraction unit 61 and a delay processing unit 62.

[0099] The voice extraction unit 61 includes a low-pass filter for extracting a voice signal related to the user's voice from the transmission signal from the transmission line 22 for voice transmission (i.e., for eliminating ambient sound and echo components). The voice signal extracted by the voice extraction unit 61 is input to the gain adjustment unit 36. The gain adjustment unit 36 ​​generates a side tone signal by adjusting the gain applied to the voice signal from the voice extraction unit 61 (an example of processing of the transmission signal).

[0100] In the loud voice suppression mode, the delay processing unit 62 performs delay processing on the side tone signal from the AGC 55. In the air conduction receiver 12, the side tone based on the side tone signal that has been subjected to such delay processing is reproduced with a predetermined delay (e.g., 200 ms or more) compared to the normal side tone (i.e., the side tone without delay processing). There is a relationship between the delay amount of the side tone in the air conduction receiver 12 and the playback volume of the side tone as shown in FIG. 11. When it is necessary to encourage the user to speak at an appropriate volume in the communication device 1 (e.g., to encourage the user to suppress the voice), the delay processing unit 62 may perform delay processing so that the combination of the delay amount of the side tone and the playback volume of the side tone is located in the uncomfortable region indicated by the level of the sound picked up by the bone conduction microphone. However, the delay processing unit 62 may be omitted in the communication device 1.

[0101] Fig. 12 is a functional block diagram showing a second modified example of the configuration of the communication device 1 shown in Fig. 8. In the second modified example shown in Fig. 12, the same components as those of the communication device 1 shown in Fig. 8 and Fig. 10 are given the same reference numerals. Furthermore, with regard to the second modified example, matters not specifically mentioned below are the same as those of the communication device 1 according to the above-mentioned second embodiment or its first modified example.

[0102] 12, in the second modification, an echo canceller / noise canceller 71 (an example of an echo canceller or a noise canceller) is provided in the transmission path 22 for voice transmission. In addition, the loopback circuit 25 of the signal processing device 3 further includes a band expander 72.

[0103] The echo cancellation / noise cancellation unit 71 performs an echo cancellation process to remove or reduce the echo component of the transmission signal, and a noise cancellation process to remove or reduce the noise component. The gain adjustment unit 36 ​​generates a side tone signal by adjusting the gain applied to the transmission signal from which the echo component and the noise component have been removed or reduced (an example of processing the transmission signal).

[0104] The band expansion unit 72 performs band expansion processing (i.e., signal processing for expanding the band of the sidetone) on the sidetone signal from the AGC 55. The sidetone signal that has been subjected to band expansion processing by the band expansion unit 72 is input to the synthesis unit 33. This band expansion processing makes the sidetone reproduced by the air conduction receiver 12 a more natural sound. However, in the communication device 1, the band expansion unit 72 may be omitted.

[0105] As described above, the embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the components described in the above embodiments to create new embodiments. [Industrial Applicability]

[0106] The communication device of the present disclosure controls the presence or absence of sidetones and the level of the sidetones depending on the user's speaking situation, thereby encouraging the user to speak at an appropriate volume, and is useful as a communication device that is equipped with a bone conduction microphone and receiver and is worn on the user's ear, head, etc. [Explanation of symbols]

[0107] 1:Telephone device 2: Earphones 3: Signal processing device 4: Signal line 5: Ears 9: Exterior housing 9A: Case 9B: Cover 9C: Opening 10: Cable cap 11: Bone conduction microphone 12: Air conduction receiver 13: Internal housing 13A:Aisle 13B: Cylinder part 15: Microphone Lover 16: Tip rubber 21: Transmission unit 22: Transmission line for sending voice 23: Receiving unit 24: Receiving transmission line 25: Loopback circuit 27: Sidetone transmission line 31: Amplification section 33: Synthesis section 35: Amplification section 36: Gain adjustment section 37: Switch section 38: First sound detector 39: Controller 41: Setting screen 48: Second sound detector 51: Volume control section 55: AGC 61: Audio extraction section 62: Delay processing section 71: Echo cancellation / noise cancellation section 72: Bandwidth expansion section

Claims

1. A bone conduction microphone that picks up the user's voice and generates a speech signal; A receiver that reproduces sound based on a call signal received from a remote device; a transmission line for transmitting the transmission signal from the bone conduction microphone to the other device; a receiving transmission path for transmitting the receiving signal to the receiver; a loopback circuit provided between the transmission line for transmitting voice and the transmission line for receiving voice, for synthesizing a side tone signal generated by processing the transmission signal with the reception signal, A communication device in which the loopback circuit operates based on one of a plurality of pre-prepared operating modes to control at least one of the on / off of a side tone reproduced by the receiver based on the side tone signal and the level of the side tone.

2. The plurality of operation modes includes a quiet voice adaptation mode; The communication device according to claim 1 , wherein in the low voice adaptation mode, the side tone is disabled only when a level of the sound picked up by the bone conduction microphone is equal to or lower than a first threshold.

3. The plurality of operation modes includes a loud noise suppression mode; The communication device according to claim 2 , wherein in the loud voice suppression mode, the level of the side tone is increased when the side tone is equal to or greater than a second threshold value that is greater than the first threshold value.

4. The communication device according to claim 3 , wherein the loopback circuit includes a microphone sound detector that detects a level of a sound picked up by the bone conduction microphone based on the transmission signal from the transmission path for transmission of the voice.

5. An input device for the user to perform an input operation is further provided, The communication device according to claim 3 , wherein the plurality of operation modes are individually turned on and off based on an input operation of the user on the input device.

6. 2. The communication device according to claim 1, wherein the loopback circuit includes a gain adjustment section that adjusts a gain for the transmission signal from the transmission path for voice transmission.

7. an ambient sound detector that detects a level of an ambient sound, excluding the user's voice, collected by the bone conduction microphone based on the transmission signal from the transmission line; The communication device according to claim 6 , wherein the gain adjustment section adjusts the gain for the transmission signal from the transmission path for voice transmission based on a level of the ambient sound.

8. a volume adjustment unit that is provided in the receiving transmission path and adjusts the volume of a sound based on the receiving signal that is reproduced by the receiver based on the receiving signal, The communication device according to claim 7 , wherein the gain adjustment unit sets the gain based on a degree of adjustment of the volume by the volume adjustment unit.

9. 3. The communication device according to claim 2, wherein the loopback circuit further includes a speech detector that detects whether or not the user is speaking based on the transmission signal from the transmission path for speech, and executes the low voice adaptation mode when it is determined based on the detection result of the speech detector that the sound picked up by the bone conduction microphone does not include speech of the user at or above a predetermined level.

10. 4. The communication device according to claim 3, wherein the loopback circuit includes a voice extraction unit that extracts a voice signal based on the user's voice from the transmission signal from the transmission path for voice transmission, and generates the side tone signal based on the voice signal.

11. The communication device according to claim 10 , wherein the loopback circuit includes a delay processing unit that delays the audio signal based on a predetermined delay time in the loud voice suppression mode, and generates the side tone signal based on the delayed audio signal.

12. 4. The communication device according to claim 3, further comprising: a noise canceller provided in each of the transmission paths for transmitting voice, the noise canceller removing or reducing a noise component of the transmission signal to be processed by the loopback circuit; and an echo canceller removing or reducing an echo component included in the transmission signal to be processed by the loopback circuit.

13. The communication device according to claim 12 , wherein the loopback circuit includes a band expansion unit that expands a frequency band of the sidetone signal.

14. A call control method for a call device, comprising: The communication device includes: A bone conduction microphone that picks up the user's voice and generates a speech signal; A receiver that reproduces sound based on a call signal received from a remote device; a transmission line for transmitting the transmission signal from the bone conduction microphone to the other device; a receiving transmission path for transmitting the receiving signal to the receiver, A side tone signal generated by processing the transmitted signal can be synthesized into the received signal; A call control method for controlling at least one of turning on and off a side tone reproduced by the receiver based on the side tone signal and a level of the side tone, based on any one of a plurality of operation modes prepared in advance.

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