JP2004015090A - Hands-free system and speaker control method - Google Patents

Abstract

An object of the present invention is to reduce the discomfort experienced by a fellow passenger while suppressing the conversation voice from being heard by a passenger, regardless of the frequency band of the voice transmitted from the other party. Provided is a hands-free system that realizes holding and a method of controlling a speaker thereof.
SOLUTION: A main speaker 110, a sub-speaker 120, and a mobile phone 130, which have directivity in a sound output direction and are arranged with the direction directed to a driver side, transmit a voice from a communication partner. The low frequency band is output from the main speaker 110, and at least a part of the range of the sound output from the main speaker 110 in which the low frequency band sound propagates in a range other than around the driver. And a control unit 140 for outputting a suppression sound for suppressing the sound from the sub speaker 120.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hands-free system for making a hands-free call and a method for controlling a speaker thereof.
[0002]
[Prior art]
With the explosive spread of mobile phones in recent years, demand for hands-free communication while driving a car has increased the demand for hands-free systems.
A hands-free system generally includes a speaker for outputting a call voice from a call partner and a microphone for collecting a driver's voice, and allows a driver to hold a mobile phone without holding a mobile phone (hands-free system). Call).
[0003]
A conventional hands-free system is provided with two speakers for outputting a call voice from a call partner, as disclosed in, for example, JP-A-5-92741 and JP-A-2001-95646. It is buried in the headrest portion of the driver's seat so that the voice of the call from the other party can be easily heard by the driver and hardly heard by the passenger.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional hands-free system, the sound output from the speaker disposed in the headrest portion propagates widely due to phenomena such as sound interference, reflection, and diffraction due to a complex sound field environment in the vehicle interior. Therefore, if there is a passenger in the car, the passenger can hear the voice of the other party, which not only discomforts the passenger but also protects the privacy and Security cannot be maintained.
[0005]
As a device for canceling the sound that propagates unnecessarily, a sound to be canceled (target sound) is detected as described in, for example, Japanese Utility Model Application Laid-Open No. 5-64894, and the target is detected from the detection result. There has been provided an apparatus using so-called ANC (Active Noise Control), which creates and outputs a cancellation sound having the same amplitude and opposite phase as a sound to cancel the target sound.
[0006]
However, using the above-described device in the conventional hands-free device and trying to cancel the speech sound that is widely propagated from the speaker, the cancellation sound of the opposite phase is obtained for the speech sound in the high frequency band. It is difficult to create, and it is not possible to sufficiently prevent the passenger from hearing the call voice.
[0007]
For example, if the sound is 1 [kHz], its wavelength is about 34 [cm]. Therefore, even if the phase of the cancellation sound is opposite to the phase of the call voice at the position of the fellow passenger, If you move only a few centimeters, the phase difference between the cancellation sound and the call voice at the destination will fluctuate greatly, and the phase of the cancellation sound will not be opposite to the phase of the call voice, making it impossible to cancel the call voice It will be.
[0008]
Accordingly, the present invention has been made in view of the above-described problems, and suppresses the call voice from being heard by a passenger, regardless of the frequency band of the call voice from the other party, and reduces the discomfort experienced by the passenger. It is an object of the present invention to provide a hands-free system and a method of controlling a speaker of the hands-free system, which realizes reduction of privacy, and protection of privacy and confidentiality.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a hands-free system according to the present invention is a hands-free system for a driver to make a hands-free call using a mobile phone, and has directivity in a sound output direction, A first speaker, a second speaker, and a call voice from a call partner of a mobile phone are output from the first speaker, and the first speaker is provided with the direction directed toward the driver. In at least a part of a range other than the surroundings and in which a sound in the low frequency band among the sounds output from the first speaker propagates, the sound interferes with the sound in the low frequency band and is suppressed. And a control unit for outputting a sound from the second speaker.
[0010]
In addition, the control unit, at least in a part of the range in which the sound of the low frequency band propagates, a sound having an opposite phase and the same amplitude as the sound of the low frequency band as a suppression sound from the second speaker. It may be featured to output.
[0011]
Here, the control unit includes a receiving unit that receives a signal output from the mobile phone, and outputs a partner voice signal indicating the content of a call voice from the other party based on the signal received by the receiving unit. A low-pass filter that receives the other-party audio signal and outputs only a low-frequency band signal of the other-party audio signal, and outputs a low-frequency band other-party audio signal output from the low-pass filter. A suppression signal generating means for generating and outputting a suppression signal by changing the phase and the amplitude by a predetermined amount, and outputting a call voice from a call partner corresponding to the call partner signal from the first speaker. The second speaker may output a suppression sound according to the suppression signal.
[0012]
Further, the hands-free system is further provided in a range other than the vicinity of the driver and in a range in which a sound in a low frequency band among sounds output from the first speaker propagates. A detection microphone for detecting a sound of the mobile phone and outputting a detection voice signal, wherein the control unit receives a signal output from the mobile phone, and performs a call based on the signal received by the reception means. A partner voice signal output means for outputting a partner voice signal indicating the content of a voice from the partner, receiving a detected voice signal output from the detection microphone, and outputting only a low frequency band signal of the detected voice signal A low-pass filter, a suppression signal creating unit that creates and outputs a suppression signal by changing an amplitude and a phase of the detected audio signal in the low frequency band, and the low-pass filter. And a suppression control means for controlling the suppression signal creation means so as to receive a low-frequency band detection sound signal output from the control section and reduce the amplitude of the received detection sound signal. Therefore, the voice of the other party in accordance with the other party's voice signal may be output, and the second speaker may output a suppression sound in accordance with the suppression signal.
[0013]
Further, the hands-free system may be mounted on an automobile.
Further, the control unit may output, from the second speaker, a suppression sound for suppressing a low-frequency band sound output from the first speaker around a front part of a headrest portion of a passenger seat. .
[0014]
Here, the hands-free system according to the present invention is a hands-free system for a driver to make a hands-free call using a mobile phone, has directivity in a sound output direction, and sets the direction to the driver's direction. A first speaker, a second speaker, and a call voice from a call partner of a mobile phone are output from the first speaker and are arranged in a range other than around the driver. And outputting a mask sound for masking the low-frequency band sound from the second speaker in at least a part of a range in which the low-frequency band sound propagates among the sounds output from the first speaker. And a control unit for causing the control unit to operate.
[0015]
Furthermore, the present invention can be realized as a control method of the first and second speakers in a hands-free system including the first and second speakers, or as a program to be executed by a computer.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
Hereinafter, a hands-free system according to the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing an appearance of a hands-free system according to the first embodiment of the present invention.
[0017]
This hands-free system is a hands-free system in which a passenger in a passenger seat 101 is prevented from hearing a call voice from a call partner, and a hands-free system provided in a headrest portion 100a of a driver's seat 100. Main speaker (first speaker) 110 and sub-speaker (second speaker) 120, a microphone 150 that collects a driver's voice and outputs a driver voice signal, and a mobile phone 130 that is brought into the vehicle And a control unit 140 for controlling the mobile phone 130, the main speaker 110, the sub-speaker 120, and the microphone 150.
[0018]
The microphone 150 has directivity for collecting sound from a predetermined direction, and is attached to the sun visor 151 such that the direction of the directivity is directed toward the driver.
The main speaker 110 and the sub-speaker 120 are embedded at both left and right ends as viewed from the front on the front side of the headrest portion 100a. The sub-speaker 120 is located on the passenger seat 101 side of the headrest portion 100a (the right side when viewed from the front), and the main speaker 110 is located on the end side of the headrest portion 100a away from the passenger seat 101 (the left side when viewed from the front). Located in.
[0019]
Further, main speaker 110 of the present embodiment has directivity in the sound output direction so as to output sound toward the front (the side opposite to rear seat 104).
Such a main speaker 110 is composed of, for example, a plurality of small speakers, and each of the small speakers has a sound output surface aligned in the same direction and arranged along a direction substantially orthogonal to the direction. Have been.
[0020]
By arranging the small speakers in this way to constitute the main speaker 110, the main speaker 110 has directivity in the sound output direction, and particularly the sound in the high frequency band among the sounds output from the main speaker 110. Propagates mainly forward, and the propagation of the sound in the left-right direction (the direction in which the driver's seat 100 and the passenger seat 101 are arranged) is suppressed.
[0021]
FIG. 2 is an arrangement showing the positional relationship between the driver A and the passenger B, the main speaker 110 and the sub-speaker 120 when the driver A is seated on the driver's seat 100 and the passenger B is seated on the passenger seat 101. FIG.
[0022]
When the driver A is seated on the driver's seat 100, the driver A faces the steering wheel 102 of the automobile 103 and the back of the head toward the headrest 100a. As a result, the right ear of the driver A is located near the front side of the main speaker 110, and the left ear of the driver A is located near the front side of the sub speaker 120.
When the passenger B sits on the passenger seat 101, the two ears of the passenger B are in a direction different from the output direction of the sound when viewed from the main speaker 110, and are located far away from the main speaker 110. Will be located.
[0023]
FIG. 3 is a functional block diagram showing a configuration of the control unit 140 shown in FIG.
The control unit 140 is operated by a user to output an operation signal corresponding to the operation. The operation unit 144 transmits and receives signals to and from the mobile phone 130. And a display unit 143 that displays, for example, the telephone number of the mobile phone 130, and a microphone 150 and a display unit 143 that are controlled according to an operation signal from the operation unit 144. The other party transmits and receives signals, and generates and outputs the other party's voice signal indicating the content of the voice from the other party transmitted from the other telephone to the mobile phone 130 via the telephone line based on the received signal. A control unit 201 serving as an audio signal generation unit, and a low-pass filter that converts a partner audio signal output from the control unit 201 into a desired signal And a filter unit 211 and the phase adjustment unit 212 and amplification unit 213.
[0024]
The main speaker 110 receives the other party's voice signal output from the control unit 201 and outputs the voice of the other party.
That is, as described above, the main speaker 110 of the present embodiment is arranged near the ear far from the passenger seat 101 of the driver sitting on the driver's seat 100, and further on the front side different from the passenger seat 101 side. Since it has directivity so as to output sound toward the user, the voice of the other party output from the main speaker 110, particularly the voice in the high frequency band, is transmitted to a passenger sitting in the passenger seat 101. Can be hard to hear.
[0025]
In addition, the low-pass filter unit 211 cuts out, for example, a signal in a high frequency band of 200 [Hz] or more from a partner audio signal output from the control unit 201, and outputs only a signal in a low frequency band.
[0026]
Then, the phase adjustment unit 212 delays the phase of the low-frequency band partner audio signal output from the low-pass filter unit 211 and outputs the signal, and the amplification unit 213 amplifies the signal output from the phase adjustment unit 212. By doing so, a suppression signal is created, and the suppression signal is output to the sub speaker 120. That is, in the present embodiment, the suppression signal generation unit is configured by the phase adjustment unit 212 and the amplification unit 213.
The sub speaker 120 receives the suppression signal and outputs a sound based on the signal.
[0027]
Here, the time for delaying the phase in the above-described phase adjustment unit 212 is uniquely determined by the positional relationship of the main speaker 110, the sub-speaker 120, and the passenger seat 101 around the headrest unit 101a. That is, at the same place around the headrest portion 101a of the passenger seat 101, the time is determined so that the sound output from the main speaker 110 and the sound output from the sub-speaker 120 have opposite phases to each other. I have. The amplification unit 213 is set to have an amplification factor such that the amplitudes of the two sounds are substantially equal to each other on the spot.
[0028]
As a result, the sound in the low frequency band (for example, less than 200 [Hz]) output from the main speaker 110 and propagated to the front periphery of the headrest portion 101a of the passenger seat 101 interferes with the sound output from the sub speaker 120. , Thereby canceling each other out. That is, in the present embodiment, the suppression sound is output from the sub speaker 120.
[0029]
FIG. 4 is an explanatory diagram showing a range in which both sounds output from the main speaker 110 and the sub speaker 120 are mutually canceled.
Among the sounds output from the main speaker 110, the sound in the high frequency band is directional in the sound output direction as shown in a range f3 in FIG. It propagates narrowly and does not propagate to the front periphery of the headrest portion 101a of the passenger seat 101. In addition, the sound in the low frequency band among the sounds output from the main speaker 110 propagates widely in the front-rear direction and the left-right direction as shown in a range f1 in FIG. Propagate to On the other hand, the sound output from the sub-speaker 120 propagates without deviation in the front-rear direction and the left-right direction, as shown in a range f2 in FIG. 4, and propagates to the front periphery of the headrest portion 101a of the passenger seat 101.
[0030]
The range in which the low-frequency band sound from the main speaker 110 and the sound from the sub-speaker 120 are both propagated, and the range in which the two sounds are in opposite phase and have the same amplitude, The range is the area to be canceled out, and as shown in a range f4 in FIG. 4, the range is the front periphery of the headrest portion 101a of the passenger seat 101.
[0031]
Further, since the sound in the low frequency band has a long wavelength, even if the passenger moves several centimeters, the sound from the sub speaker 120 at the destination and the sound in the low frequency band from the main speaker 110 are different. The sound from the main speaker 110 is canceled in a wide range without a large change in the phase difference.
[0032]
As described above, in the present embodiment, the main speaker 110 has directivity in the sound output direction, and the direction is directed to the driver A side different from the passenger seat 101 side. It is possible to make it difficult for a passenger in the front passenger seat 101 to hear a high-frequency region sound among the output voices from the other party, and from the sub-speaker 120, around the front of the headrest part 101a of the front passenger seat 101, By outputting a sound of the same amplitude and opposite phase as the sound of the low frequency band propagated from the main speaker 110, the sound of the low frequency band out of the call sound from the other party output from the main speaker 110 is also output to the passenger seat 101. Can be made inaudible to passengers. As a result, when the driver is making a hands-free call, the voice of the other party output from the main speaker 110 may be difficult to hear to the passenger in the passenger seat 101 over the entire frequency range. It is possible to reduce the discomfort experienced by the passenger due to the call voice.
[0033]
Also, the sound output from the sub-speaker 120 can be heard by the driver A as a call sound from the call partner, similarly to the sound output from the main speaker 110, so that the call sound from the call partner is not It is possible to make it difficult for only the passengers to hear while preventing the passenger A from becoming hard to hear.
[0034]
Further, in the present embodiment, the low-pass filter 211, the phase adjuster 212, and the amplifier 213 are configured to output a suppression sound based on a partner audio signal output from the controller 201 and input to the main speaker 110. Since the suppression signal is generated, the time for delaying the phase by the phase adjustment unit 212 and the amplification factor of the amplification unit 213 can be made substantially constant, and the signal processing can be simplified.
[0035]
In the present embodiment, the sound is output from the sub-speaker 120 so as to cancel the low-frequency band sound transmitted from the main speaker 110 around the front of the headrest portion 101a of the passenger seat 101. The place where the sound is canceled is not limited to the area around the front of the headrest section 101a, and the sound from the main speaker 120 is canceled at least in a range including the area around the front of the headrest section 101a. Sound may be output.
[0036]
(Embodiment 2)
In the basic configuration according to the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted, and only the features that are characteristic of the present embodiment will be described in detail. .
[0037]
FIG. 5 is a configuration diagram illustrating an appearance of a hands-free system according to the second embodiment of the present invention.
The hands-free system is characterized in that the voice of a call partner output from the main speaker 110 is masked with music or the like, and includes two audio speakers 203 for outputting the music or the like.
[0038]
FIG. 6 is a functional block diagram showing the configuration of the control unit 140 shown in FIG.
As shown in FIG. 6, the control unit 140 according to the present embodiment includes a car navigation unit 141 that operates as a car navigation system, and an audio unit 142 that operates as audio equipment such as a radio and a CD player.
[0039]
Then, the control unit 201 of the control unit 140 controls the above-described car navigation unit 141 according to an operation signal from the operation unit 144, and indicates its own location on a map based on a signal output from the car navigation unit 141. An image is displayed on the display unit 143, and a guide voice signal having a content indicating a guide voice for guiding a destination is output to the audio speaker 203. The control unit 201 controls the above-described audio unit 142 in response to an operation signal from the operation unit 144, and outputs an audio signal indicating the content of music on a radio or a CD based on a signal output from the audio unit 142. , To the audio speaker 203.
[0040]
For example, when the driver operates the operation unit 144, an image indicating his / her location is displayed on the display unit 143, and radio or CD music and guide voice are output from the audio speaker 203.
Further, hands-free sub-speaker 120 according to the present embodiment receives a voice signal of the other party, outputs a voice of the other party based on the signal, and outputs the voice in the same direction as main speaker 110. Has a directivity so that is directed forward.
[0041]
Thus, in the present embodiment, when the driver makes a hands-free call, the call voice from the call partner is output from the main speaker 110 and the sub-speaker 120 near the both ears of the driver A. The call sound can be made easier for the driver to hear, and the main speaker 110 and the sub-speaker 120 each have directivity in the sound output direction, and the direction is directed to a driver side different from the passenger seat 101. Therefore, it is possible to prevent a voice in a high frequency band from being heard by a passenger in the passenger seat 101 among the voices.
[0042]
Further, control unit 201 in the present embodiment controls audio unit 142 when outputting a partner audio signal to main speaker 110 and sub-speaker 120 in response to an operation signal from operation unit 144, and controls audio unit 142, for example, An audio signal is created by receiving a radio wave and outputting a signal based on the radio wave from the audio unit 142, or reading music data from a CD and outputting a signal based on the music data from the audio unit 142. And outputs it to two audio speakers 203. At this time, the control unit 201 controls the car navigation unit 141 to execute navigation, and based on the execution result, creates a guide audio signal in accordance with a signal output from the car navigation unit 141, and outputs the guide audio signal. The output may be performed by the speaker 203. That is, in the present embodiment, the control unit 201 is configured as an audio control unit and a car navigation control unit.
[0043]
Further, in a state where the audio signal or the guide audio signal is being output, the control unit 201 outputs the other party's audio signal to the main speaker 110 and the sub speaker 120 in response to the operation signal from the operation unit 144. The audio signal and the guide audio signal are amplified and output to the two audio speakers 203, and the volume of the music and the guide audio output from the two audio speakers 203 is increased.
[0044]
Accordingly, in the present embodiment, when the driver makes a hands-free call, the call sound of the call partner is output from the hands-free main speaker 110 and the sub-speaker 120, and the sound of the low frequency band among the call sounds is output. Even if the call sound propagates to the passenger seat 101 side, the call sound is masked by the music and the guide sound output from the audio speaker 203, so that the call sound is transmitted to the passenger in the passenger seat 101 over the entire frequency band. You can prevent it from being heard. That is, in the present embodiment, music and guide sound are used as mask sounds, the main speaker 110 and the sub speaker 120 are used as first speakers, and the audio speaker 203 is used as second speakers.
[0045]
In the above-described case, the control unit 201 outputs the audio signal and the guide audio signal to the two audio speakers 203, but only one of the two audio speakers 203 that is closer to the passenger seat 101 is provided. On the other hand, an audio signal or a guide audio signal may be output, or may be amplified and output. In this case, the volume of music, voice, and the like output from one audio speaker 203 near the passenger seat 101 increases.
[0046]
FIG. 7 shows the volume of the call sound and the music when the call sound is output from the main speaker 110 and the sub-speaker 120 and the music is output from the audio speaker 203 closer to the passenger seat 101 as described above. It is a schematic diagram which shows typically. FIG. 7A shows the sound volume around the front of the headrest portion 100a of the driver's seat 100, and FIG. 7B shows the sound volume around the front of the headrest portion 101a of the passenger seat 101.
[0047]
As shown in FIG. 7B, in the vicinity of the front of the headrest portion 101a of the passenger seat 101, low-frequency band sound of the call sound output from the main speaker 110 and the sub-speaker 120 propagates to the passenger seat 101 side. Therefore, although the sound volume is present to some extent, music is output from the audio speaker 203 closer to the passenger seat 101, so that the sound volume of the music is higher than the volume of the call voice over a wide frequency band. Exists.
[0048]
On the other hand, around the front of the headrest portion 100a of the driver's seat 100, as shown in FIG. 7A, the volume of the call voice output from the main speaker 110 and the sub speaker 120 is large over a wide frequency band, Since the music is output only from the audio speaker 203 closer to the passenger seat 101, the sound volume is sufficiently lower than the volume of the call voice.
[0049]
In this way, when the driver is making a hands-free call, by outputting music only from the audio speaker 203 closer to the passenger seat 101, the driver can disturb the call voice from the other party by the music. Can be easily heard without being heard.
[0050]
Further, in the present embodiment, the sub speaker 120 outputs the call voice from the other party based on the other party's voice signal similarly to the main speaker 110, but outputs the music and the guide voice similarly to the audio speaker 203. You may let it. That is, the sub speaker 120 and the audio speaker 203 may be used as the second speaker.
In this case, the sub-speaker 120 is buried in the headrest portion 100a with the sound output direction facing the passenger seat 101, and outputs the sound according to the audio signal and the guide audio signal from the control unit 201.
[0051]
As a result, when the driver is making a hands-free call, the sub-speaker 120 does not output the call sound from the call partner, so that the call sound is prevented from being heard by the passenger in the passenger seat 101. In addition, music and guide sound are output from the sub-speaker 120 toward the passenger seat 101, so that the call sound propagating from the main speaker 120 to the passenger seat 101 is further transmitted by the sound from the sub-speaker 120. Masking can be performed reliably.
[0052]
Further, in the present embodiment, the communication voice from the communication partner output from main speaker 120 is masked by music or guide voice by audio unit 142 or car navigation unit 141, but may be masked by another sound.
[0053]
(Embodiment 3)
In the basic configuration according to the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted, and only the features that are characteristic of the present embodiment will be described in detail. .
[0054]
FIG. 8 is a functional block diagram of a hands-free system according to the third embodiment of the present invention.
This hands-free system is characterized in that a sound to be canceled is detected, and a sound for canceling the sound is output from the sub-speaker 120 based on the detection result. As shown in FIG. And a detection microphone 152 that detects a sound to be detected.
[0055]
The detection microphone 152 is mounted in the vehicle so as to detect a sound around the headrest portion 101a of the passenger seat 101, and when the sound is detected, the sound content around the detection microphone 152 is determined according to the detection result. The detected voice signal is output to the control unit 140.
[0056]
Further, low-pass filter section 211 of control unit 140 in the present embodiment cuts out the high-frequency band signal from the detected audio signal output from detection microphone 152 and outputs only the low-frequency band signal.
[0057]
The phase adjustment unit 212 delays the phase of the detected audio signal in the low frequency band output from the low-pass filter unit 211 via the control unit 201 according to the control signal from the control unit 210, and outputs the delayed signal.
Then, the amplification unit 213 amplifies the signal output from the phase adjustment unit 212 according to the control signal from the control unit 201, and outputs the signal to the sub speaker 120 as a suppression signal.
[0058]
Here, the control unit 201 outputs a control signal to the phase adjustment unit 212 and the amplification unit 213 so that the amplitude of the detected audio signal in the low frequency band output from the low-pass filter 211 approaches zero, and Is delayed by the phase adjustment unit 212 or the amplification factor is converted by the amplification unit 213.
[0059]
That is, in the present embodiment, so-called ANC (Active Noise Control) is performed, and low-frequency band sound propagating around the detection microphone 152, that is, around the front of the headrest portion 101a of the passenger seat 101 is inverted in phase. In addition, the sound output from the sub-speaker 120 is feedback-controlled so that the sound volume is positively approached to zero by canceling out the sound with the same amplitude.
[0060]
Thus, in the present embodiment, similar to Embodiment 1, the main speaker 110 has directivity in the sound output direction, and the direction is directed to the driver side different from the passenger seat 101 side. In addition, it is possible to make the high frequency band sound of the call sound from the call partner output from the main speaker 110 inaudible to the fellow passenger in the passenger seat 101, and to prevent the sound in front of the headrest portion 101 a of the passenger seat 101. The sound in the low frequency band is positively canceled by the sound output from the sub-speaker 120, so that the sound in the low frequency band out of the call sound from the other party output from the main speaker 110 is also transmitted to the passenger seat 101. It can be difficult for passengers to hear. As a result, when the driver is making a hands-free call, the voice of the other party output from the main speaker 110 may be difficult to hear to the passenger in the passenger seat 101 over the entire frequency range. It is possible to reduce the discomfort experienced by the passenger due to the call voice.
[0061]
In the above-described case, the sound is output from the sub-speaker 120 so as to cancel the sound in front of the headrest portion 101a of the passenger seat 101. However, the sound canceling range is limited to the area in front of the headrest portion 101a. Instead, the range may include at least the periphery thereof.
[0062]
By the way, in the above-described case, the detection microphone 152 detects the sound in front of the headrest portion 101a of the passenger seat 101, but may detect the sound in front of the headrest portion 100a of the driver's seat 100.
[0063]
In this case, the sound in the low frequency band around the front of the headrest portion 100a of the driver's seat 100 is positively canceled by the sound output from the sub-speaker 120. Of the so-called road noise generated by the vibration of the vehicle being propagated into the vehicle interior, the road noise particularly in a low frequency band can be reduced around the front of the headrest portion 100a. As a result, the driver reduces the surrounding road noise. Therefore, the driver operates the operation unit 144 of the control unit 140 to lower the volume of the call sound within a range where the call sound output from the main speaker 110 can be heard. be able to. In other words, it is possible to reduce the volume of low-frequency band sound that propagates to the vicinity of the headrest portion 101a of the passenger seat 101 in the call sound.
[0064]
As a result, in the same manner as described above, the voice from the other party output from the main speaker 110 can be made inaudible to the passenger in the passenger seat 101 over the entire frequency range, and the Discomfort experienced by a person can be reduced.
[0065]
As described above, the hands-free system according to the present invention has been described using Embodiments 1 to 3, but the present invention is not limited to these.
For example, in Embodiments 1 to 3, one main speaker 110 and one sub speaker 120 are provided, but two or more may be provided.
[0066]
In the first to third embodiments, the main speaker 110 and the sub speaker 120 are buried in the headrest portion 100a. However, for example, the two speakers 110 and 120 are provided in another portion such as a ceiling in a vehicle or a sun visor 151. May be.
[0067]
Further, in the first to third embodiments, the low frequency band is described as being lower than 200 [Hz], but may be higher than 200 [Hz], and the low-pass filter unit 211 in the first embodiment may cut the other party's audio signal. The frequency band may be set in accordance with the frequency band of the call voice propagating to the front periphery of the headrest portion 101a of the passenger seat 101. In the third embodiment, the frequency band of the detected voice signal cut by the low-pass filter 211 is The frequency may be set according to the road noise around the headrest portion 100a of the driver's seat 100 in front of the headrest portion 101a or the frequency band of the call voice around the front vicinity of the headrest portion 101a of the passenger seat 101.
[0068]
Further, in the first to third embodiments, the hands-free system has been described as being mounted on an automobile, but may be mounted on another vehicle.
Further, in the first to third embodiments, the mobile phone 130 is connected to the control unit 140 via a cable and a connector. However, for example, the mobile phone 130 is connected via a wireless communication medium such as Bluetooth (registered trademark of [The Bluetooth SIG Inc.]). The mobile phone 130 may be connected to the control unit 140.
[0069]
【The invention's effect】
As is apparent from the above description, the hands-free system according to the present invention is a hands-free system for a driver to make a hands-free call using a mobile phone, and has a directivity in a sound output direction. A first speaker, a second speaker, and a second speaker, the direction of which is directed toward the driver side, and a call voice from a call partner of a mobile phone output from the first speaker; In a range other than the vicinity of the driver, at least a part of the range in which the sound in the low frequency band among the sounds output from the first speaker propagates, the sound interferes with the sound in the low frequency band, and A control unit for outputting the suppression sound to be suppressed from the second speaker.
[0070]
Accordingly, when the driver makes a hands-free call using a mobile phone, a call voice from a call partner is output from the first speaker. However, it is possible to prevent the driver from spreading to a range other than the vicinity of the driver, and to prevent the passenger from hearing the speech sound of the high frequency band even if there is a passenger in the range. In addition, in a range other than the vicinity of the driver, at least a part of the range in which the voice of the low frequency band propagates in the voice of the call, the voice interferes with the voice of the low frequency band and is suppressed. Since the suppression sound is output from the second speaker, even if there is a passenger in a part of the range, it is possible to suppress that the low frequency band speech sound is heard for the passenger. As a result, the voice of the call from the other party is suppressed from being heard by the passenger over the entire frequency band, the discomfort experienced by the passenger is reduced, and privacy protection and confidentiality are maintained. Can be realized.
[0071]
In addition, the control unit, at least in a part of the range in which the sound of the low frequency band propagates, a sound having an opposite phase and the same amplitude as the sound of the low frequency band as a suppression sound from the second speaker. It may be featured to output.
This makes it possible to cancel the low-frequency band call sound by the suppression sound, and as a result, it is possible to further suppress the call sound from the call partner from being heard by the fellow passenger.
[0072]
Here, the control unit includes a receiving unit that receives a signal output from the mobile phone, and outputs a partner voice signal indicating the content of a call voice from the other party based on the signal received by the receiving unit. A low-pass filter that receives the other-party audio signal and outputs only a low-frequency band signal of the other-party audio signal, and outputs a low-frequency band other-party audio signal output from the low-pass filter. A suppression signal generating means for generating and outputting a suppression signal by changing the phase and the amplitude by a predetermined amount, and outputting a call voice from a call partner corresponding to the call partner signal from the first speaker. The second speaker may output a suppression sound according to the suppression signal.
[0073]
Accordingly, the low-pass filter and the suppression signal creation unit create a suppression signal for outputting a suppression sound based on the other party audio signal output from the other party audio signal output unit and input to the first speaker, The amount of the change in the phase and the amplitude performed by the signal generation means can be made substantially constant, and the signal processing can be simplified.
[0074]
Further, the hands-free system is further provided in a range other than the vicinity of the driver and in a range in which a sound in a low frequency band among sounds output from the first speaker propagates. A detection microphone for detecting a sound of the mobile phone and outputting a detection voice signal, wherein the control unit receives a signal output from the mobile phone, and performs a call based on the signal received by the reception means. A partner voice signal output means for outputting a partner voice signal indicating the content of a voice from the partner, receiving a detected voice signal output from the detection microphone, and outputting only a low frequency band signal of the detected voice signal A low-pass filter, a suppression signal creating unit that creates and outputs a suppression signal by changing an amplitude and a phase of the detected audio signal in the low frequency band, and the low-pass filter. And a suppression control means for controlling the suppression signal creation means so as to receive a low-frequency band detection sound signal output from the control section and reduce the amplitude of the received detection sound signal. Therefore, the voice of the other party in accordance with the other party's voice signal may be output, and the second speaker may output a suppression sound in accordance with the suppression signal.
[0075]
Accordingly, the suppression control unit performs the feedback control on the suppression signal generation unit so that the amplitude of the detected voice signal is reduced, so that the volume around the detection microphone can be positively approached to zero.
[0076]
Further, the hands-free system may be mounted on an automobile.
As a result, when a car driver makes a hands-free call using a mobile phone, it is possible to prevent the voice of the call from the other party from being heard by the passenger of the car over the entire frequency band. it can.
[0077]
Further, the control unit may output, from the second speaker, a suppression sound for suppressing a low-frequency band sound output from the first speaker around a front part of a headrest portion of a passenger seat. .
As a result, it is possible to prevent a call voice from a call partner from being heard by a passenger in the passenger seat over the entire frequency band.
[0078]
Here, the hands-free system according to the present invention is a hands-free system for a driver to make a hands-free call using a mobile phone, has directivity in a sound output direction, and sets the direction to the driver's direction. A first speaker, a second speaker, and a call voice from a call partner of a mobile phone are output from the first speaker and are arranged in a range other than around the driver. And outputting a mask sound for masking the low-frequency band sound from the second speaker in at least a part of a range in which the low-frequency band sound propagates among the sounds output from the first speaker. And a control unit for causing the control unit to operate.
[0079]
Accordingly, when the driver makes a hands-free call using a mobile phone, a call voice from a call partner is output from the first speaker. However, it is possible to prevent the driver from spreading to a range other than the vicinity of the driver, and to prevent the passenger from hearing the speech sound of the high frequency band even if there is a passenger in the range. In addition, a mask sound for masking the low-frequency band voice is in a range other than the vicinity of the driver and in at least a part of a range in which the low-frequency band voice propagates in the call voice. Since the sound is output from the speaker, even if there is a passenger in a part of the range, it is possible to prevent the passenger from hearing the voice of the low frequency band. To reduce the discomfort experienced by the passenger by suppressing the voice from the hand from being heard by the passenger over the entire frequency band, and to realize privacy protection and confidentiality. Can be.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an appearance of a hands-free system according to a first embodiment of the present invention.
FIG. 2 is a layout diagram showing a positional relationship between a driver and a passenger, and a main speaker and a sub speaker.
FIG. 3 is a functional block diagram of the above.
FIG. 4 is an explanatory diagram showing a range in which both sounds output from the main speaker and the sub-speaker are mutually canceled.
FIG. 5 is a configuration diagram illustrating an appearance of a hands-free system according to a second embodiment of the present invention.
FIG. 6 is a functional block diagram of the above.
FIGS. 7A and 7B are schematic diagrams schematically showing the volume of a call voice and music. FIG.
FIG. 8 is a functional block diagram of a hands-free system according to a third embodiment of the present invention.
[Explanation of symbols]
100 Driver's seat
100a Headrest part
101 Passenger seat
101a Headrest part
102 handle
103 car
104 rear seat
110 Main speaker
120 sub speaker
130 mobile phone
140 control unit
143 display
144 operation unit
150 microphone
151 Sun visor
201 control unit
204 interface
211 Low-pass filter section
212 Phase adjustment unit
213 Amplifier

Claims (17)

A hands-free system for a driver to make a hands-free call using a mobile phone,
A first speaker having directivity in a sound output direction, the first speaker being arranged with the direction facing the driver side;
A second speaker;
A call voice from a call partner of a mobile phone is output from the first speaker, and a low-frequency band sound of a range other than around the driver and output from the first speaker. A control unit for outputting, from the second speaker, a suppression sound that interferes with the sound in the low frequency band and suppresses the interference in at least a part of the range in which the sound propagates. . The control unit includes:
In at least a part of a range in which the sound in the low frequency band propagates, a sound having an opposite phase and the same amplitude as the sound in the low frequency band is output from the second speaker as a suppression sound. The hands-free system according to claim 1. The control unit includes:
Receiving means for receiving a signal output from the mobile phone;
Based on the signal received by the receiving unit, a partner voice signal output unit that outputs a partner voice signal indicating the content of a call voice from the partner,
A low-pass filter that receives the other party's audio signal and outputs only a low-frequency band signal of the other party's audio signal,
By changing the phase and amplitude of the low-frequency band partner audio signal output from the low-pass filter by a predetermined amount, a suppression signal creating unit that creates and outputs a suppression signal,
Causing the first speaker to output a call voice from a call partner according to the call partner voice signal;
3. The hands-free system according to claim 1, wherein a suppression sound according to the suppression signal is output from the second speaker. 4. The hands-free system further comprises:
It is arranged in a range other than the vicinity of the driver, and is disposed within a range in which a sound in a low frequency band among sounds output from the first speaker propagates, and detects a surrounding sound to generate a detection sound signal. Equipped with a detection microphone to output,
The control unit includes:
Receiving means for receiving a signal output from the mobile phone;
Based on the signal received by the receiving unit, a partner voice signal output unit that outputs a partner voice signal indicating the content of the voice from the other party,
A low-pass filter that receives a detection audio signal output from the detection microphone and outputs only a signal in a low frequency band among the detection audio signals,
Suppression signal creating means for creating and outputting a suppression signal by changing the amplitude and phase of the detected audio signal in the low frequency band,
A low-frequency band detection audio signal output from the low-pass filter is received, and a suppression control unit that controls the suppression signal generation unit so that the amplitude of the received detection audio signal is reduced,
Causing the first speaker to output a call voice from a call partner according to the call partner voice signal;
3. The hands-free system according to claim 1, wherein a suppression sound according to the suppression signal is output from the second speaker. 4. The hands-free system according to any one of claims 1 to 4, wherein the hands-free system is mounted on an automobile. The control unit causes the second speaker to output a suppression sound that suppresses a low-frequency band sound output from the first speaker in the vicinity of the front of the headrest portion in the passenger seat. The described hands-free system. The hands-free system according to claim 5, wherein the first speaker is provided in a headrest portion of a driver's seat. A hands-free system for a driver to make a hands-free call using a mobile phone,
A first speaker having directivity in a sound output direction, the first speaker being arranged with the direction facing the driver side;
A second speaker;
A call voice from a call partner of a mobile phone is output from the first speaker, and a low-frequency band sound of a range other than around the driver and output from the first speaker. A control unit for outputting a mask sound for masking the low frequency band sound from the second speaker in at least a part of a range in which the sound propagates. The control unit includes:
Receiving means for receiving a signal output from the mobile phone;
Based on the signal received by the receiving unit, a partner voice signal output unit that outputs a partner voice signal indicating the content of a call voice from the partner,
Audio means for outputting an audio signal indicating the content of the music;
When the other party audio signal is output from the other party audio output means, the audio control means to output an audio signal to the audio means,
Causing the first speaker to output a call voice from a call partner according to the call partner voice signal;
9. The hands-free system according to claim 8, wherein music according to the audio signal is output as a mask sound from the second speaker. 10. The hands-free system according to claim 8, wherein the hands-free system is mounted on an automobile. The control unit includes:
Receiving means for receiving a signal output from the mobile phone;
Based on the signal received by the receiving unit, a partner voice signal output unit that outputs a partner voice signal indicating the content of a call voice from the partner,
Car navigation means for performing car navigation and outputting a guide audio signal indicating the content of the guide audio for notifying information about the car navigation,
Car navigation control means for outputting a guide audio signal to the car navigation means when the other party audio signal is being output from the other party audio output means,
Causing the first speaker to output a call voice from a call partner according to the call partner voice signal;
The hands-free system according to claim 10, wherein a guide sound corresponding to the guide sound signal is output as a mask sound from the second speaker. The said control unit makes the 2nd speaker output the mask sound which masks the low frequency band sound output from a 1st speaker in the front periphery of the headrest part of a passenger seat. Or the hands-free system according to 11. The hands-free system according to any one of claims 10 to 12, wherein the first speaker is disposed at a headrest portion of a driver's seat. A first speaker, a second speaker, and a control unit for controlling the first and second speakers, the first speaker having directivity in a sound output direction, and the direction being directed to the driver side; A method for controlling a first and a second speaker in a hands-free system for a driver to make a hands-free call using a mobile phone,
In the control unit, a call voice output step of outputting a call voice from a call partner by a mobile phone from the first speaker;
In a range other than the vicinity of the driver, at least a part of a range in which a sound in a low frequency band among sounds output from the first speaker propagates, the sound interferes with the sound in the low frequency band, And a step of outputting a suppression sound from the second speaker. In the suppression sound output step, a sound having an opposite phase and the same amplitude as the sound in the low frequency band is used as a suppression sound from the second speaker in at least a part of a range in which the sound in the low frequency band propagates. The method of controlling the first and second speakers according to claim 14, wherein the output is performed. A first speaker, a second speaker, and a control unit for controlling the first and second speakers, the first speaker having directivity in a sound output direction, and the direction being directed to the driver side; A method for controlling a first and a second speaker in a hands-free system for a driver to make a hands-free call using a mobile phone,
In the control unit, a call voice output step of outputting a call voice from a call partner by a mobile phone from the first speaker;
A mask sound that masks the low-frequency band sound in at least a part of a range other than the vicinity of the driver and in which the low-frequency band sound propagates among the sounds output from the first speaker. And outputting a mask sound from the second speaker. A program for a hands-free system, the program causing a computer to execute steps in the method for controlling the first and second speakers according to any one of claims 14 to 16.

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