Patent Publication Number: US-2023156408-A1

Title: Speaker Device Having Built-In Microphone, and Noise Cancellation Method Using Same

Description:
TECHNICAL FIELD 
     The present invention relates, in general, to a speaker device having a built-in microphone and a noise cancellation method using the speaker device, and more particularly a speaker device having a built-in microphone and a noise cancellation method using the speaker device, in which sound transmitted to a medium is picked up with a microphone built in the speaker device, and a reverse phase of sound that is picked up is output, thus cancelling noise. 
     BACKGROUND ART 
     Unless otherwise indicated herein, the material described in this section is not the related art for the claims of this application, and is not admitted to fall within the purview of the related art. 
     It is very difficult to cancel ambience noise, that is, background noise, generated in a space. 
     The ambience noise may be introduced in all directions, and is naturally amplified or eliminated by reflection or diffraction. 
     In particular, the ambience noise generated in a general space such as a room, an office, a vehicle, or an airplane, and a personal living space deteriorates the quality of life, and also causes a decrease in work efficiency as well as concentration. 
     Further, protracted exposure to noise may cause discomfort to a user, whereby, in order to prevent this problem, when headphones or earphones are worn or the volume of a sound system is increased, noise-induced hearing loss may occur, so that a vicious cycle may be repeated. 
     Generally, the method for cancelling the ambience noise includes a method of insulating or absorbing sound in the space. There is a problem in that it is difficult to perform sound insulation or absorption construction in a general living environment. 
     Sound insulation or absorption construction may be performed using a product with excellent sound insulation or absorption effect in the process of establishing a space. However, it is difficult to add construction in a state where facility construction is already completed. 
     Accordingly, there is a need for technology for cancelling ambience noise without additional construction. 
     DISCLOSURE 
     Technical Problem 
     An object of the present invention is to efficiently cancel spatial noise by installing a microphone module and a speaker driver at the same point. 
     Further, an object of the present invention is to prevent the vibration of a speaker driver installed at the same point from being transmitted to a microphone module. 
     Furthermore, an object of the present invention is to improve the structure of a microphone module, thus improving the pickup rate of sound transmitted to a medium. 
     Furthermore, an object of the present invention is to improve the structure of a microphone module, thus preventing howling or feedback generated by a speaker driver. 
     Furthermore, an object of the present invention is to efficiently transmit the vibration of a speaker driver to a medium by fixing the speaker driver to the medium. 
     Furthermore, an object of the present invention is to improve the structure of a speaker driver, thus setting the output efficiency and sound quality of the speaker driver with a simple operation. 
     Furthermore, an object of the present invention is to reproduce clear sound with spatial noise cancelled through an additional speaker module. 
     Furthermore, the present invention is not limited to the above-described objects, and it is obvious that other objects may be derived from the following description, 
     Technical Solution 
     In accordance with an aspect of the present invention to accomplish the above objects, there is provided a speaker device having a built-in microphone including a microphone module configured to pick up sound from a medium to generate a sound pickup signal, a speaker driver configured to transmit vibration corresponding to a reverse-phase signal of the sound pickup signal to the medium, and a controller configured to receive the sound pickup signal from the microphone module, generate the reverse-phase signal of the sound pickup signal, and transmit the reverse-phase signal to the speaker driver. 
     Here, the microphone module may include a high-pitched contact microphone configured to pick up sound from the medium using a first band as a target band, and generate a first sound pickup signal, a low-pitched contact microphone configured to pick up sound from the medium using a second band, which is a frequency band lower than the first band, as the target band, and generate a second sound pickup signal, and a microphone controller configured to generate the sound pickup signal by summing the first sound pickup signal and the second sound pickup signal. 
     Here, the microphone module may further include a feedback blocking housing configured to accommodate the high-pitched contact microphone and the low-pitched contact microphone, the feedback blocking housing being formed of an anti-magnetic material to prevent an influence of external magnetism and formed in a parabolic shape to improve a sound pickup rate. 
     Here, the microphone module may further include, in order to improve the pickup rate of sound transmitted from the medium, a funnel-shaped high-pitched boost plate configured to contact at a first end thereof with the medium and transmit the vibration of the medium to the high-pitched contact microphone through a second end thereof, and a donut-shaped low-pitched boost plate configured to contact at a first end thereof with the medium and transmit the vibration of the medium to the low-pitched contact microphone through a second end thereof. 
     Here, the feedback blocking housing may include a rubber plate including one or more through holes arranged at regular intervals along an arc thereof, and covering an opening that is in contact with the medium, the high-pitched boost plate may transmit vibration to the high-pitched contact microphone with the rubber plate interposed therebetween, and the low-pitched boost plate may be positioned inside the rubber plate, and include one or more protrusions corresponding to the through holes, the protrusions being positioned to pass through the through holes. 
     Here, the speaker driver may include a vibrator contacting on a surface thereof with the medium to transmit vibration thereto, a magnet configured to transmit the vibration to the vibrator, a voice coil positioned outside the magnet to be spaced apart therefrom, and configured to generate a magnetic field in response to the reverse-phase signal, a voice-coil fixing part configured to fix a position of the voice coil outside the voice coil, and a fixing bracket fixed at a first end thereof to the voice-coil fixing part and fixed at a second end thereof to the medium so as to prevent a position of the voice coil relative to the medium from being changed. 
     Here, the vibrator may include on a surface thereof contacting the medium a microphone holding part recessed inwards, and the microphone module may be positioned in the microphone holding part to be spaced apart from the vibrator. 
     Here, the speaker device may further include a microphone module supporting pole fixedly coupled at a first end thereof to the microphone module, and coupled at a middle portion thereof to the speaker driver, wherein the microphone module supporting pole and the speaker driver may be coupled to each other with a rubber ring interposed therebetween, so as to prevent the vibration of the speaker driver from being transmitted to the microphone module. 
     Here, the speaker driver may further include a voice-coil support part positioned inside the voice-coil fixing part and including a fixing groove formed on an inner circumference thereof to fix the voice coil and a first thread formed on an outer circumference thereof, the voice coil may be fixed in the fixing groove, and a second thread may be formed on an inner circumference of the voice-coil fixing part to correspond to the first thread, so that a position of the voice-coil support part is changed by rotation of the voice-coil fixing part. 
     Here, the speaker device may further include a speaker module oriented in a direction opposite to the microphone module and configured to generate sound in response to a signal applied by a user. 
     Here, the speaker driver may further include a wave spring positioned on a surface of the magnet so that the magnet returns to an original position thereof after vibration, and having multiple layers formed such that a thickness thereof is increased in proportion to a distance from the magnet. 
     In accordance with an aspect of the present invention to accomplish the above objects, there is provided a noise cancellation method through a speaker device having a built-in microphone in which a speaker and a microphone are integrated with each other, the noise cancellation method including receiving a sound pickup signal from a medium through the microphone, generating a reverse-phase signal of the sound pickup signal, and transmitting vibration corresponding to the reverse-phase signal to the medium through the speaker having a shape of accommodating the microphone. 
     Here, an output generated through the speaker may be prevented from being input into the microphone by a parabolic feedback blocking housing that accommodates the microphone. 
     Here, the feedback blocking housing may be formed of an anti-magnetic material. 
     Here, the feedback blocking housing may be accommodated in the vibrator of the speaker that transmits vibration to the medium. 
     Here, the feedback blocking housing may be coupled to be spaced apart from the vibrator by a microphone supporting pole, and the vibration of the vibrator is not transmitted to the microphone by a rubber ring interposed between the microphone supporting pole and the vibrator. 
     Here, receiving the sound pickup signal may include generating a first phase signal of a balanced audio signal using a signal received from a high-pitched contact microphone of the microphone, generating a second phase signal of the balanced audio signal using a signal received from a low-pitched contact microphone of the microphone, generating a summed sound pickup signal by applying a reverse phase to either of the first phase signal and second phase signal of the balanced audio signal, and receiving the sound pickup signal. 
     Advantageous Effects 
     In accordance with the present invention having the above configuration, it is possible to efficiently cancel spatial noise by installing a microphone module and a speaker driver at the same point. 
     Further, according to the present invention, it is possible to prevent the vibration of a speaker driver installed at the same point from being transmitted to a microphone module. 
     Furthermore, according to the present invention, it is possible to improve the structure of a microphone module, thus improving the pickup rate of sound transmitted to a medium. 
     Furthermore, according to the present invention, it is possible to improve the structure of a microphone module, thus preventing howling or feedback generated by a speaker driver. 
     Furthermore, according to the present invention, it is possible to efficiently transmit the vibration of a speaker driver to a medium by fixing the speaker driver to the medium. 
     Furthermore, according to the present invention, it is possible to improve the structure of a speaker driver, thus setting the output efficiency and sound quality of the speaker driver with a simple operation. 
     Furthermore, according to the present invention, it is possible to reproduce clear sound with spatial noise cancelled through an additional speaker module. 
     Effects of the present embodiments are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the description of the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a sectional view illustrating a speaker device having a built-in microphone according to an embodiment of the present invention; 
         FIG.  2    is an exploded view illustrating the speaker device having a built-in microphone according to an embodiment of the present invention; 
         FIG.  3    is an exploded view illustrating a microphone module according to an embodiment of the present invention; 
         FIG.  4    is an exploded view illustrating a speaker driver according to an embodiment of the present invention; 
         FIG.  5    is a processing flow diagram of using a single device according to an embodiment of the present invention; 
         FIG.  6    is a processing flow diagram of using multiple connections according to an embodiment of the present invention; 
         FIG.  7    is a diagram illustrating the use of the apparatus attached to the interior of a vehicle according to an embodiment of the present invention; 
         FIG.  8    is a diagram illustrating a noise cancelling area according to an embodiment of the present invention; 
         FIG.  9    is a sectional view of a device with a speaker for reproducing sound added, according to an embodiment of the present invention; and 
         FIG.  10    is a flowchart of a noise cancelling method according to an embodiment of the present invention. 
     
    
    
     BEST MODE 
     The present invention is described in detail below with reference to the accompanying drawings. Repeated descriptions and descriptions of known functions and configurations which have been deemed to make the gist of the present invention unnecessarily obscure will be omitted below. The embodiments of the present invention are intended to fully describe the present invention to a person having ordinary knowledge in the art to which the present invention pertains. Accordingly, the shapes, sizes, etc. of components in the drawings may be exaggerated to make the description clear. 
     The basic condition of a noise cancelling method is to generate a reverse-phase wavelength at the same position as a position where noise is generated, thus cancelling the wavelength. 
     When a noise source is blocked by a wall or obstacle, a point at which noise is generated may be regarded as the wall or obstacle, and the reverse-phase wavelength may be generated at the wall or obstacle to cancel noise. 
     In this case, a speaker driver may be used as a device for reproducing sound, and a microphone module for picking up noise is also required. 
     The microphone module may pick up noise, perform reverse-phase processing for the picked up signal, and transmit the signal to the speaker driver. The speaker driver may output the signal subjected to the reverse-phase processing to cancel noise. 
     However, sound reproduced through the speaker driver may be picked up by the microphone module, and the picked up sound may be amplified through an amplifier and then output again by the speaker driver. 
     This is referred to as howling or feedback. The feedback may easily occur when the microphone module is positioned on-axis with respect to a voice coil of the speaker driver. 
     Therefore, the speaker driver and the microphone module cannot be generally installed at the same position. 
     Moreover, the feedback continuously increases the amplification amount of the amplifier, thus causing damage to an amplifier circuit, a power circuit, and a speaker driver. 
     The feedback may be easily generated at a specific frequency, and may affect a full frequency band as the bandwidth of a quality factor (Q) value is widened. 
     Therefore, there is a need for a method of preventing the feedback by blocking a frequency in which the feedback occurs using a graphic equalizer (EQ). 
     However, the above-described method is problematic in that it may change the characteristics of the frequency and the reverse phase of the input frequency may be precisely processed, so that it is difficult to use the method in a noise cancelling environment. 
     Furthermore, when the microphone module and the speaker driver are installed at distinct positions so as to prevent feedback, noise that is to be cancelled through the microphone module cannot be precisely picked up, and should be corrected through a Digital Signal Processor (DSP). 
     The feedback occurs because both the speaker driver and the microphone module have certain directivity. Thus, in order to prevent the feedback, it is advantageous to position the speaker driver and the microphone module in an off-axis state. 
     However, as described above, the off-axis state makes it impossible to pick up the correct sound, so that there is a need for a method in which the speaker driver and the microphone module are positioned in the on-axis state, while preventing the feedback. 
     Thus, according to an embodiment of the present invention, a cover capable of blocking a magnetic field so as to prevent feedback even on the on-axis is used as a cover of the microphone module, and it is possible to prevent feedback by positioning the microphone module inside a diaphragm of the speaker driver. 
     Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
       FIG.  1    is a sectional view illustrating a speaker device having a built-in microphone according to an embodiment of the present invention. 
     Referring to  FIG.  1   , the speaker device having a built-in microphone according to an embodiment of the present invention may include a microphone module that picks up sound from a medium to generate a sound pickup signal, a speaker driver that transmits a vibration corresponding to a reverse-phase signal of the sound pickup signal to the medium, and a controller that receives the sound pickup signal from the microphone module, generates the reverse-phase signal of the sound pickup signal, and transmits the reverse-phase signal to the speaker driver. 
     Here, the microphone module may include a high-pitched contact microphone  101 , a low-pitched contact microphone  103 , a high-pitched boost plate  105 , a low-pitched boost plate  107 , a rubber plate  109 , and a feedback blocking housing  111 . 
     The speaker driver may include a magnet  113 , a voice coil  115 , a vibrator  117 , and a fixing bracket  119 . 
     According to an embodiment of the present invention, in order to efficiently cancel spatial noise, the speaker driver may be installed in the same position as the position of the microphone module. 
     The reason why the speaker driver is installed in the same position as the microphone module is because a pickup position is set to be the same as a reproduction position, so that the processing power for correcting a phase difference that may occur when the speaker driver and the microphone module are at different positions is reduced, and an error is minimized. 
     To this end, an embodiment of the present invention may propose one device, in which the microphone module is disposed in the speaker driver for creating a vibration, and a feedback prevention structure is applied, thus being capable of picking up a noise signal and simultaneously reproducing a reverse-phase signal. 
     In detail, the vibrator  117  of the speaker driver may have a parabolic shape, and the microphone module may be mounted therein to separately pick up high-pitched sound and low-pitched sound. 
     In this regard, the microphone module may be structurally separated so as not to be affected by the vibration of the speaker driver. 
     In detail, the vibrator  117  of the speaker driver may include on a surface contacting the medium a microphone holding part recessed inwards, and the microphone module may be positioned in the microphone holding part to be spaced apart from the vibrator  117 . 
     Furthermore, the apparatus may further include a microphone module supporting pole  121  that is fixedly coupled at one end thereof to the microphone module and coupled at a middle portion thereof to the speaker driver so as to prevent the vibration of the speaker driver from being transmitted to the microphone module. A rubber ring  123  may be interposed between the microphone module supporting pole  121  and the speaker driver. 
     Through the above-described structure, according to an embodiment of the present invention, the microphone module and the speaker driver are precisely seated on the medium, so that pickup and reproduction can be arranged to be completely independently operated. 
     Furthermore, the microphone module supporting pole  121  may allow the microphone module to be precisely adsorbed to the medium, and may be firmly attached to a target medium using an adhesive on the rubber plate  109 . 
     The feedback blocking housing  111  may accommodate the high-pitched contact microphone  101  and the low-pitched contact microphone  103 , may be formed of an anti-magnetic material (magnetic shielding) to prevent the influence of external magnetism, and may be formed in the parabolic shape to improve a sound pickup rate. 
     Furthermore, an embodiment of the present invention may include an integration terminal  125  for connecting the speaker driver and the microphone module. 
     Here, the microphone module may use piezo diaphragms of different sizes like the high-pitched contact microphone  101  and the low-pitched contact microphone  103  to differently pick up the center frequency of sound to be picked up. 
     This can increase the range of a target sound pickup frequency band. 
     According to an embodiment of the present invention, the microphone module for picking up sound is installed in the same position as a position where the speaker driver is installed, but the microphone module may pick up only noise on a contact surface without picking up noise in the air using a contact microphone (e.g. piezo microphone), thus preventing feedback. 
     Furthermore, as described above, the microphone module includes the magnetic shielding feedback blocking housing to prevent the magnetic field of the speaker driver from affecting the module and thereby preventing the feedback due to the magnetic field. 
     Here, the vibrator  117  may be connected to the magnet  115 , and vibration may be transmitted through the vibrator  117  to the medium in a moving magnetic driving method. 
     At this time, the vibration of the vibrator  117  may not affect the microphone module through the rubber ring  123 . 
     The fixing bracket  119  may be connected to a voice-coil fixing part of the speaker driver or an external housing of the speaker driver to be fixed to the medium. 
     In this case, the microphone module and the vibrator  117  may be horizontally mounted on the medium by the fixing bracket  119 . 
       FIG.  2    is an exploded view illustrating the speaker device having a built-in microphone according to an embodiment of the present invention. 
     Referring to  FIG.  2   , the speaker device having the built-in microphone according to an embodiment of the present invention may include a microphone module  210  and a speaker driver  220 . 
     As shown in  FIG.  2   , the microphone module  210  and the speaker driver  220  may be configured such that respective components are stacked and coupled, and may be formed such that the microphone module  210  is coupled to the inside of the speaker driver  220 . 
       FIG.  3    is an exploded view illustrating the microphone module according to an embodiment of the present invention. 
     Referring to  FIG.  3   , the microphone module  210  according to an embodiment of the present invention may include a high-pitched contact microphone  305  that picks up sound from the medium using a first band as a target band and generates a first sound pickup signal, a low-pitched contact microphone  311  that picks up sound from the medium using a second band, which is a frequency band lower than the first band, as the target band and generates a second sound pickup signal, and a microphone controller that generates the sound pickup signal by summing the first sound pickup signal and the second sound pickup signal. 
     The first band and the second band may include a crossover band, and the sound pickup signal may correspond to the crossover band. 
     Here, the high-pitched contact microphone  305  and the low-pitched contact microphone  311  may connect a negative terminal (−) to the same ground, and each may generate a balanced audio signal (the balanced audio signal is resistant to noise characteristics) using a positive terminal (+) as an individual output. 
     The balanced audio signal also has the effect of amplifying the entire signal. 
     The signals of sound picked up by the high-pitched contact microphone  305  and the low-pitched contact microphone  311  are summed. At this time, an overlapping crossover area substantially becomes a target band. 
     In this case, the crossover frequency may be adjusted by a user. 
     For example, a crossover frequency range may be set in the DSP, and a user may adjust a crossover frequency by designating the high-pitched contact microphone  305  as a High Pass Filter (HPF) and designating the low-pitched contact microphone  311  as a Low Pass Filter (LPF). 
     Here, the high-pitched contact microphone  305  may have a relatively smaller area than the low-pitched contact microphone  311 , and the high-pitched contact microphone  305  and the low-pitched contact microphone  311  may be stacked while being spaced apart from each other so that central axes thereof are aligned with each other. 
     Furthermore, the microphone module  210  according to an embodiment of the present invention may further include a funnel-shaped high-pitched boost plate  301  that contacts at one end thereof with the medium and transmits the vibration of the medium to the high-pitched contact microphone  305  through the other end so as to improve the pickup rate of sound transmitted from the medium. 
     The high-pitched boost plate  301  is formed in a funnel shape to amplify micro-vibration and efficiently transmit the amplified vibration to the high-pitched contact microphone  305 . 
     The material of the high-pitched boost plate  301  may use a material (e.g. forming a density to have the same sound propagation speed as ABS-concrete) that may amplify vibration, so that vibration can be efficiently absorbed even in a high-density medium that is difficult to absorb vibration. 
     Furthermore, the microphone module  210  according to an embodiment of the present invention may further include a donut-shaped low-pitched boost plate  307  that contacts at one end thereof with the medium and transmits the vibration of the medium to the low-pitched contact microphone  311  through the other end so as to improve the pickup rate of sound transmitted from the medium. 
     The low-pitched boost plate  307  may be positioned such that an outer circumference thereof is aligned with an outer circumference of the low-pitched contact microphone  311 , and the high-pitched boost plate  301  may be positioned in an inner through hole of the low-pitched boost plate  307 . 
     Furthermore, the microphone module  210  according to an embodiment of the present invention may further include a feedback blocking housing  313  that accommodates the high-pitched contact microphone  305  and the low-pitched contact microphone  311  and is formed in a parabolic shape so as to improve a sound pickup rate. 
     In this regard, the feedback blocking housing  313  may be formed in a parabolic shape to amplify sound generated in the medium and pick up only sound generated in a targeted direction. 
     Furthermore, the feedback blocking housing  313  may be formed of an anti-magnetic material or a magnetic shielding type, so that it is not affected by the magnetic effect of the magnet of the speaker driver as will be described later, thereby eliminating a feedback phenomenon. 
     Furthermore, the microphone module  210  including the feedback blocking housing  313  is of a contact microphone type that is not affected by acoustic characteristics, so people or ambience noise is not well picked up. 
     Here, the feedback blocking housing  313  may include a rubber plate  303  covering an opening that is in contact with the medium. 
     In this regard, the rubber plate  303  may be formed of a material capable of amplifying a targeted frequency band of the medium, and may acquire a targeted frequency by adjusting a size and a thickness. 
     In this regard, the rubber plate  303  may put its edge on an edge so as to efficiently amplify and pick up the frequency, thus improving responsiveness. 
     Furthermore, the rubber plate  303  may treat an outer edge in a ring shape so as to pick up correct spot sound. 
     Through the ring shape, the microphone module  210  according to an embodiment of the present invention may block sound introduced from the outside by compression when the microphone module is mounted on the medium, and may be precisely attached to the medium, so that low-pitched sound pickup characteristics may be increased by increasing proximity effect. 
     The rubber plate  303  includes one or more through holes arranged at regular intervals along an arc, and the low-pitched boost plate  307  may be positioned inside the rubber plate  303  and may include one or more protrusions corresponding to the through holes of the rubber plate  303 , so that the protrusions may be positioned to pass through the through holes of the rubber plate  303 . 
     Here, the high-pitched contact microphone  305  and the low-pitched contact microphone  311  may be at least one of a piezo microphone and a laser microphone. 
     Furthermore, the speaker device having the built-in microphone according to an embodiment of the present invention may further include a microphone module supporting pole  315  as a component for coupling the microphone module  210  with the speaker driver. 
     In this regard, the microphone module supporting pole  315  may be fixedly coupled at one end thereof to the feedback blocking housing  313 , and may be coupled at a middle portion thereof to the speaker driver. 
     Here, the feedback blocking housing  313  and the microphone module supporting pole  315  may be formed to have corresponding threads, and may be fastened to each other through a screw-type fastening method. 
     Furthermore, the speaker device having the built-in microphone according to an embodiment of the present invention may couple the microphone module supporting pole  315  with the speaker driver with the rubber ring  317  interposed therebetween, so as to prevent the vibration of the speaker driver from being transmitted to the microphone module  210 . 
       FIG.  4    is an exploded view illustrating a speaker driver according to an embodiment of the present invention. 
     Referring to  FIG.  4   , the speaker driver  220  according to an embodiment of the present invention includes a vibrator  401 , a magnet  415 , a voice coil  409 , a voice-coil fixing part  417 , and a fixing bracket  407 , and is attached to the medium to generate vibration. 
     The voice coil  409  generates a magnetic field in response to a reverse-phase signal that is applied through the microphone module. 
     The signal may be a sound signal that is output to the speaker driver  220 , and may move the magnet  415  by the magnetic field. 
     The voice-coil fixing part  417  may accommodate the components, and may fix the position of the voice coil  409  outside the voice coil  409 . 
     The voice-coil fixing part  417  may prevent the position of the voice coil  409  relative to the medium from being changed. 
     The voice coil  409  may be positioned in the voice-coil fixing part  417 , and the position of the voice coil relative to the magnet  415  may be changed. 
     The reason why the relative position is changed is because sound properties vary depending on the position of the voice coil  409  relative to the magnet  415 . 
     Generally, the voice coil  409  and the magnet  415  should be positioned one-half the center of the voice coil  409 . When the voice coil  409  and the magnet  415  move apart from each other, an output is reduced and low-pitched sound is reduced, so that only high-pitched sound is consequently heard. As the voice coil  409  and the magnet  415  come near to each other, an output is increased and low-pitched sound is increased. 
     Therefore, the speaker driver  220  according to an embodiment of the present invention allows the position of the magnet  415  or the voice coil  409  to be delicately shifted, so that efficiency and sound quality may be adjusted as desired by a user. 
     The speaker driver  220  according to an embodiment of the present invention further includes a voice-coil support part  411  that is positioned inside the voice-coil fixing part  417 , and has a fixing groove formed on an inner circumference thereof to fix the voice coil  409 , and a first thread formed on an outer circumference thereof. The voice coil  409  may be fixed in the fixing groove, and may have a second thread formed on the inner circumference of the voice-coil fixing part  417  to correspond to the first thread, so that the position of the voice-coil support part  411  may be changed by the rotation of the voice-coil fixing part  417 . 
     The magnet  415  may be positioned inside the voice coil  409  to be moved by the magnetic field. 
     In this regard, the movement may be vertical vibration, and the vibration of the magnet  415  may be transmitted to the vibrator  401 . 
     A surface of the vibrator  401  may be in contact with the medium to transmit the vibration to the medium. 
     The vibrator  401  may be formed in a parabolic shape to include a microphone holding part that is recessed inwards from a surface contacting the medium, and the microphone module may be positioned in the microphone holding part to be spaced apart from the vibrator  401 . 
     A through hole is formed in the center of the vibrator  401 , and the microphone module supporting pole passes through the through hole to be fixed by the rubber ring. One end of the microphone module supporting pole may be fixedly coupled to the microphone module or the feedback blocking housing of the microphone module. 
     A suspension ring  413  may be included to prevent damage due to accumulated shocks by vibration between the vibrator  401  and the magnet  415 , and may be formed of a soft material. 
     A support spring  419  may be positioned on a surface of the magnet  415  so that the magnet  415  may return to its original position after vibration. 
     The support spring  419  may be a wave spring having multiple layers. 
     Here, the support spring  419  may make the multiple layers of the wave spring  613  have different thicknesses, thereby increasing a reaction rate at low output and preventing distortion from occurring even at high output. 
     For example, the wave spring according to an embodiment of the present invention may have a multi-layered structure including a layer a, a layer b, and a layer c, and may be configured such that the thicknesses of the layers are a&lt;b&lt;c. 
     The wave spring may move only the layer a when small sound of low output is reproduced, and may move the layers a, b, and c together when large sound of high output is reproduced. 
     Therefore, the wave spring according to an embodiment of the present disclosure has different spring restoring force depending on an output. Thus, even if sound having very strong transient characteristics is instantaneously input, the wave spring does not cause distortion, may have a fast restoring force, and may maximize a damping factor. 
     Furthermore, the wave spring does not increase the size of a product because its thickness may be reduced by at least ½ compared to the existing spring, and has a very strong restoring force, so that the spring is not deformed even after long-term use. 
     Furthermore, the speaker driver  220  may further include a top cover  405  and a bottom cover  421  to accommodate each component, and may use the voice-coil fixing part  417  as a side cover. 
     In order to improve the performance of the speaker driver  220 , an aluminum foil may be further provided on an inner surface of the voice coil  409 . 
     The fixing bracket  407  may be fixed at one end thereof to the voice-coil fixing part  417  and fixed at the other end thereof to the medium so as to prevent the position of the voice coil  409  relative to the medium from being changed. 
     Furthermore, the fixing bracket  407  may be coupled at one end thereof to the top cover  405  to be fixed to the medium. 
     The thread may be formed on the inner circumference of one end of the fixing bracket  407 , and the thread may be formed on the outer circumference of the voice-coil fixing part  417  or the top cover  405  to correspond to the thread of the fixing bracket and engage therewith in a screw-type fastening manner. 
     Furthermore, the fixing bracket  407  may be formed in a cylindrical shape, and may further include a contact part on the outer circumference of one end of the fixing bracket contacting the medium to extend outwards. The contact part may include at least one through hole to be coupled to the medium. 
       FIG.  5    is a processing flow diagram of using a single device according to an embodiment of the present invention, and  FIG.  6    is a processing flow diagram of using multiple connections according to an embodiment of the present invention. 
     Referring to  FIGS.  5  and  6   , the speaker device having the built-in microphone according to an embodiment of the present invention may make a reverse-phase signal using an analog circuit in which no latency occurs, amplify the signal and transmit the signal to the speaker driver, so as to prevent a wavelength from being distorted due to latency between the sound pickup of the microphone module and the reproduction of the speaker driver. 
     The above-described method may reproduce a reverse-phase waveform that is input in real time, and may cancel vibration noise generated in a targeted spot. 
     In this regard, the targeted spot may be a part that needs noise cancellation selected by a user. 
     Furthermore, the adjustment of gain and/or phase, the detection of the feedback frequency, etc. may be digitally controlled, if necessary, regardless of an analog circuit. 
     In this case, the digital control may use a wireless or Bluetooth device, and may use a portable device and a smart device or an infotainment system of a car. 
     Here, the level of measured noise or cancelled noise may be visually monitored using the above-described device, and may be adjusted to fit for a user&#39;s purpose by adjusting a parameter. 
     As shown in  FIG.  5    or  FIG.  6   , the case of using the single device and the case where multiple devices are connected may be separately operated. When the multiple devices  are connected, a processing algorithm may be added according to the connected number, thus making it possible to more efficiently manage a frequency. 
     According to an embodiment of the present invention, an area where noise is cancelled may be processed with an image by recognizing positions where multiple devices are attached and converting into a distance. 
     Here, according to an embodiment of the present invention, an effective mounting point may be expected and the mounting point may be guided. 
     According to an embodiment of the present invention, the processing area of noise cancellation may be imaged, and a user may specify the area within a possible range. 
     Thus, according to an embodiment of the present invention, a gain controller or the like may be automatically applied. 
       FIG.  7    is a diagram illustrating the use of the apparatus attached to the interior of a vehicle according to an embodiment of the present invention. 
     Referring to  FIG.  7   , one or more speaker devices, each having a built-in microphone, according to an embodiment of the present invention may be attached to a space such as the vehicle and then used. 
     Here, one or more speaker devices, each having a built-in microphone, according to an embodiment of the present invention may be mounted in the lower area of a dashboard, the interior of a ceiling, an A pillar, a trunk hood, or under a chair inside the vehicle, or may be formed in an adsorption type to be mounted on glass or sunroof. 
     Furthermore, the speaker device having the built-in microphone according to an embodiment of the present invention may be installed and used in any spot or part where vibration may be generated and noise may be introduced, without being limited to the above-described positions. 
       FIG.  8    is a diagram illustrating a noise cancelling area according to an embodiment of the present invention. 
     Referring to  FIG.  8   , an embodiment of the present invention may calculate directivity according to a position where the device is mounted. 
     According to an embodiment of the present invention, when one or more devices are mounted and used, an area where noise is cancelled may be set, and noise may be controlled to be cancelled within the set area. 
     In this case, one or more directivity may be generated through a volume control. 
     Here, an embodiment of the present invention may be implemented in the form of an application. The application may include one or more functions, such as the function of recognizing one or more devices, the function of controlling the volume and phase to set the degree of attenuation, the function of simulating using space through various modes (car mode, room mode, and desktop mode), the function of setting a direction, and the function of detecting a picked-up signal of a microphone to suggest a. point where an optimal attenuation characteristic is expected. 
       FIG.  9    is a sectional view of a device with a speaker for reproducing sound added, according to an embodiment of the present invention. 
     Referring to  FIG.  9   , a speaker device  910  having a built-in microphone according to an embodiment of the present invention may further include a speaker module  920  that generates sound in response to a signal applied by a user in a direction opposite to a surface attached to the medium. 
     The speaker module  920  may increase the frequency of using the speaker device  910  having the built-in microphone so as to cancel spatial noise, and may reproduce sound having clear sound quality in a state where the spatial noise is cancelled even in a space where noise is generated. 
       FIG.  10    is a flowchart of a noise cancelling method according to an embodiment of the present invention. 
     Referring to  FIG.  10   , the method for cancelling the noise through the speaker device having the built-in microphone in which the speaker and the microphone are integrated according to an embodiment of the present invention first receives a sound pickup signal from the medium through the microphone at step S 1010 . 
     In this case, step S 1010  may include the step of generating a first phase signal of a balanced audio signal using a signal received from a high-pitched contact microphone, the step of generating a second phase signal of the balanced audio signal using a signal received from a low-pitched contact microphone, the step of generating a summed sound pickup signal by applying a reverse phase to either of the first phase signal and second phase signal of the balanced audio signal, and the step of receiving the sound pickup signal. 
     Furthermore, the noise cancelling method according to an embodiment of the present invention generates a reverse-phase signal of the sound pickup signal at step S 1020 . 
     Furthermore, the noise cancelling method according to an embodiment of the present invention transmits vibration corresponding to the reverse-phase signal to the medium through the speaker having the shape of accommodating the microphone at step S 1030 . 
     The output generated through the speaker may be prevented from being input into the microphone by the parabolic feedback blocking housing that accommodates the microphone. 
     In this case, the feedback blocking housing may be formed of an anti-magnetic material. 
     The feedback blocking housing may be accommodated in the vibrator of the speaker that transmits vibration to the medium. 
     The feedback blocking housing may be coupled to be spaced apart from the vibrator by the microphone supporting pole, and the vibration of the vibrator may not be transmitted to the microphone by the rubber ring interposed between the microphone supporting pole and the vibrator. 
     As described above, the speaker device having the built-in microphone and noise cancellation method using the speaker device according to the present invention are not limited and applied to the configurations and operations of the above-described embodiments, but all or some of the embodiments may be selectively combined and configured such that the embodiments may be modified in various ways.