A noise reduction device, an electromechanical device, and a debugging method

Abstract

The invention relates to noise reduction equipment, electromechanical equipment and a debugging method. The noise reduction equipment comprises a plurality of sound acquisition units which are configured to respectively acquire sound emitted by a sound source to be subjected to noise reduction and convert the sound into first electric signals; the signal amplification unit is configured to superpose the received first electric signals of the plurality of sound acquisition units and amplify the superposed signals according to a target amplification coefficient so as to generate a second electric signal, and the target amplification coefficient is a corresponding amplification coefficient under the condition that the loudspeaker does not generate howling; and the loudspeaker is arranged towards the sound source to be subjected to noise reduction and is used for converting the second electric signal into a sound signal. According to the technical scheme, the noise reduction output signal and the input signal can be synchronized, so that the noise reduction effect is ensured.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202610023985.2 (22) Application Date 2026.01.08 (71) Applicant Shanghai Shengyin Technology Co., Ltd. Address No. 3, Lane 889, Suide Road, Putuo District, Shanghai 200331 (72) Inventors Chen Lijun, Ye Chunyan, Zhang Shanshan (74) Patent Agency Beijing King & Wood Mallesons 11256 Patent Attorney Lin Ke (51) Int.Cl. G10K 11 / 178 (2006.01) (54) Invention Title Noise Reduction Device, Electromechanical Equipment and Debugging Method (57) Abstract This disclosure relates to a noise reduction device, electromechanical equipment and debugging method. The noise reduction device includes multiple sound acquisition units configured to acquire sound emitted by the noise source to be reduced and convert it into a first electrical signal; a signal amplification unit configured to superimpose the first electrical signals received from the multiple sound acquisition units and amplify the superimposed signal according to a target amplification factor to generate a second electrical signal, wherein the target amplification factor is the amplification factor corresponding to the condition that the speaker does not produce feedback; and a speaker, positioned towards the noise source to be reduced, for converting the second electrical signal into a sound signal. The technical solution disclosed herein enables the noise reduction output signal to be synchronized with the input signal, thereby ensuring the noise reduction effect. Claims 1 page, Description 11 pages, Drawings 8 pages, CN 121811843 A 2026.04.07 CN 1 21 81 18 43 A 1. A noise reduction device, characterized in that it comprises: a plurality of sound acquisition units configured to respectively acquire the sound emitted by the noise source to be reduced and convert it into a first electrical signal; a signal amplification unit configured to superimpose the first electrical signals received from the plurality of sound acquisition units, and amplify the superimposed signal according to a target amplification factor to generate a second electrical signal, the target amplification factor being the amplification factor corresponding to the condition that the speaker does not whistle; and a speaker, disposed toward the noise source to be reduced, for converting the second electrical signal into a sound signal. 2. The noise reduction device according to claim 1, characterized in that it further comprises: a coefficient adjustment unit configured to adjust the amplification factor of the signal amplification unit to a target amplification factor according to the detection result of the whistle detection unit, the target amplification factor being the maximum amplification factor that makes the speaker not whistle; and a whistle detection unit configured to detect whether the speaker whistles. 3. The noise reduction device according to claim 2, wherein the coefficient adjustment unit is further configured to: increase the amplification coefficient of the signal amplification unit in response to determining that the detection result of the feedback detection unit indicates that the speaker has not emitted feedback; and decrease the amplification coefficient of the signal amplification unit in response to determining that the detection result of the feedback detection unit indicates that the noise reduction speaker has emitted feedback.A large amplification factor is used until the detection result of the feedback detection unit indicates that the noise-canceling speaker no longer emits feedback, so that the current amplification factor can be used as the target amplification factor. 4. The noise-canceling device according to claim 1, wherein a plurality of sound acquisition units are uniformly distributed relative to the radiation port of the noise source to be reduced, the number of the plurality of sound acquisition units is positively correlated with the size of the radiation port of the noise source to be reduced, and the sound acquisition unit includes a microphone. 5. The noise-canceling device according to claim 1, wherein a plurality of sound acquisition units are uniformly distributed around the radiation port of the speaker. 6. The noise-canceling device according to claim 1, wherein the signal amplification unit includes: a first amplifier, the inverting input terminal of the first amplifier is configured to receive a first electrical signal from the plurality of sound acquisition units, the non-inverting input terminal of the first amplifier is electrically connected to a reference voltage, and the output terminal of the first amplifier is electrically connected to the inverting input terminal of the first amplifier via a first resistor. 7. The noise-canceling device according to claim 1, wherein the first amplifier is an analog operational amplifier. 8. An electromechanical device, comprising a sound-emitting device, further comprising the noise-canceling device according to any one of claims 1 to 7, wherein a plurality of sound acquisition units of the noise-canceling device are oriented toward the sound-emitting device. 9. The electromechanical equipment according to claim 8, characterized in that the electromechanical equipment includes a range hood, and the noise reduction device is disposed at the vent of the range hood; or the electromechanical equipment includes a central air conditioner, and the noise reduction device is disposed at the vent of the central air conditioner. 10. A method for noise reduction, characterized in that the method is used for the noise reduction device according to any one of claims 1 to 7, comprising: determining whether the noise reduction speaker is whistling, and increasing the amplification factor of the signal amplification unit in response to determining that the noise reduction speaker is not whistling, and decreasing the amplification factor of the signal amplification unit until the noise reduction speaker no longer whistles in response to determining that the noise reduction speaker is whistling, so as to use the current amplification factor as the target amplification factor of the amplification unit. Claims 1 / 1 page 2 CN 121811843 A Noise Reduction Device, Electromechanical Equipment and Debugging Method Technical Field

[0001] The embodiments of this disclosure generally relate to the field of acoustics and electricity, and more specifically to a noise reduction device, electromechanical equipment and debugging method. Background Art

[0002] In active noise cancellation technology, such as noise cancellation devices, correction is performed using an error microphone. This correction process involves a calculation process. This calculation process takes a certain amount of time. Therefore, there is a certain time delay between the noise-cancelled output signal and the input signal. This time delay affects the noise cancellation effect.

[0003] Therefore, traditional noise cancellation devices suffer from noise cancellation effects due to the time delay. Summary of the Invention

[0004] To address the above problems, this disclosure provides a noise cancellation device, system, and electronic device that enables the noise-cancelled output to...The signal is synchronized with the input signal to ensure the noise reduction effect.

[0005] According to a first aspect of the present disclosure, a noise reduction device is provided. The noise reduction device includes a plurality of sound acquisition units configured to acquire the sound emitted by the noise source to be reduced and convert it into a first electrical signal; a signal amplification unit configured to superimpose the first electrical signals received from the plurality of sound acquisition units and amplify the superimposed signal according to a target amplification factor to generate a second electrical signal, wherein the target amplification factor is the amplification factor corresponding to the condition that the speaker does not whistle; and a speaker, disposed toward the noise source to be reduced, for converting the second electrical signal into a sound signal.

[0006] In some embodiments, the noise reduction device further includes: a coefficient adjustment unit configured to adjust the amplification factor of the signal amplification unit to a target amplification factor according to the detection result of the whistle detection unit, wherein the target amplification factor is the maximum amplification factor that makes the speaker not whistle; and a whistle detection unit configured to detect whether the speaker whistles.

[0007] In some embodiments, the coefficient adjustment unit is further configured to: increase the amplification coefficient of the signal amplification unit in response to determining that the detection result of the feedback detection unit indicates that the speaker has not given feedback; and decrease the amplification coefficient of the signal amplification unit in response to determining that the detection result of the feedback detection unit indicates that the noise-canceling speaker has given feedback, until the detection result of the feedback detection unit indicates that the noise-canceling speaker no longer gives feedback, so as to use the current amplification coefficient as the target amplification coefficient.

[0008] In some embodiments, a plurality of sound acquisition units are uniformly distributed relative to the radiation port of the noise source to be reduced, the number of the plurality of sound acquisition units is positively correlated with the size of the radiation port of the noise source to be reduced, and the sound acquisition units include microphones.

[0009] In some embodiments, a plurality of sound acquisition units are uniformly distributed around the radiation port of the speaker.

[0010] In some embodiments, the signal amplification unit includes: a first amplifier, the inverting input terminal of the first amplifier is configured to receive a first electrical signal from the plurality of sound acquisition units, the non-inverting input terminal of the first amplifier is electrically connected to a reference voltage, and the output terminal of the first amplifier is electrically connected to the inverting input terminal of the first amplifier via a first resistor.

[0011] In some embodiments, the first amplifier is an analog operational amplifier. It is worth noting that using an analog operational amplifier can significantly improve the speed, making the noise reduction output signal synchronized with the input signal, thereby ensuring the noise reduction effect.

[0012] According to a second aspect of the present disclosure, an electromechanical device is provided, which includes a sound-generating device and a noise reduction device according to the first aspect of the present disclosure, wherein a plurality of sound acquisition units of the noise reduction device are oriented toward the sound-generating device.

[0013] In some embodiments, the electromechanical device includes a range hood, and the noise reduction device is disposed at the vent of the range hood;Or the electromechanical equipment includes a central air conditioner, and the noise reduction device is installed at the air vent of the central air conditioner.

[0014] According to a third aspect of the present disclosure, a method for noise reduction is provided, which is used in the noise reduction device according to the first aspect of the present disclosure. The method includes: determining whether the noise reduction speaker is whistling, and increasing the amplification factor of a signal amplification unit in response to determining that the noise reduction speaker is not whistling, and decreasing the amplification factor of the signal amplification unit until the noise reduction speaker no longer whistles in response to determining that the noise reduction speaker is whistling, so as to use the current amplification factor as the target amplification factor of the amplification unit.

[0015] According to the technical solution of the present disclosure, the noise reduction device includes a plurality of sound acquisition units configured to respectively acquire the sound emitted by the noise source to be reduced and convert it into a first electrical signal; a signal amplification unit configured to superimpose the first electrical signals received by the plurality of sound acquisition units, and amplify the superimposed signal according to a target amplification factor to generate a second electrical signal, the target amplification factor being the amplification factor corresponding to the condition that the speaker does not whistle; and a speaker, disposed toward the noise source to be reduced, for converting the second electrical signal into a sound signal. The noise reduction device enables the noise reduction output signal to synchronize with the input signal, thereby ensuring the noise reduction effect.

[0016] It should be understood that the content described in this section is not intended to identify key or important features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Brief Description of the Drawings

[0017] The above and other features, advantages and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and with reference to the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements.

[0018] FIG1 shows a schematic diagram of an active noise reduction device.

[0019] FIG2 shows a perspective view of a noise reduction device according to an embodiment of this disclosure.

[0020] FIG3 shows a side view of a noise reduction device according to an embodiment of this disclosure.

[0021] FIG4 shows a bottom view of a noise reduction device according to an embodiment of this disclosure.

[0022] FIG5 shows a circuit diagram of a plurality of sound acquisition units according to an embodiment of this disclosure.

[0023] FIG6 shows a circuit diagram of a signal amplification unit according to an embodiment of this disclosure.

[0024] FIG7 shows a block diagram of an electromechanical device according to an embodiment of the present disclosure.

[0025] FIG8 shows a flowchart of a method for noise reduction according to an embodiment of the present disclosure.

[0026] FIG9 shows a schematic block diagram of an example electronic device for a method for noise reduction that can be used to implement an embodiment of the present disclosure. Detailed Description

[0027] Exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings, including various embodiments of the present disclosure.Details are provided to aid understanding and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0028] The term “comprising” and its variations as used herein indicate an open-ended inclusion, i.e., “including but not limited to.” Unless specifically stated otherwise, the term “or” means “and / or.” The term “based on” means “at least partially based on.” The terms “one example embodiment” and “one embodiment” mean “at least one example embodiment.” The term “another embodiment” means “at least one additional embodiment of the specification 2 / 11 page 4 CN 121811843 A.” The terms “first,” “second,” etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0029] As described above, in conventional active noise cancellation techniques, such as noise cancellation devices, correction is performed via an error microphone. This correction process involves a computational process. This computational process takes a certain amount of time. Therefore, there is a certain time delay between the noise-reduced output signal and the input signal. This time delay affects the noise reduction effect.

[0030] Figure 1 shows a schematic diagram of an active noise reduction device. For example, noise enters the ANC (Active Noise Cancellation) controller 114 after passing through the reference microphone 112, and the signal input to the secondary speaker 118 (e.g., as a noise-reducing speaker) is corrected by the error microphone 116. That is, there is a calculation process involved. It should be understood that the calculation process described here includes, for example, at the ANC controller 114, correcting the signal from the reference microphone 112 based on the signal from the error microphone 116, and then transmitting the corrected signal to the secondary speaker 118. Therefore, there is a certain time delay between the noise-reduced output signal (e.g., the sound signal output by the secondary speaker 118) and the input signal (e.g., the signal from the reference microphone 112). This time delay affects the noise reduction effect.

[0031] To compensate for this time delay, for example, a certain distance must be maintained between the noise source and the secondary speaker 118 to match the required computing speed. Obviously, maintaining this required distance requires a large amount of space. Therefore, this distance is difficult to achieve in space-constrained environments.

[0032] In summary, the shortcoming of traditional active noise cancellation schemes is that the noise-cancelled output signal has a certain time delay relative to the input signal, which affects the noise cancellation effect.

[0033] Furthermore, it is worth noting that active noise cancellation technology can, for example, employ an adaptive filter system, corresponding to active...Noise reduction systems, for example, are feedback active noise reduction systems, which include error microphones (e.g., error microphones) to correct the coefficients of adaptive filters. This implementation is complex in structure and algorithm, and requires high computing power. Especially when the sound source (e.g., noise source) is close to the ambient noise microphone (e.g., reference microphone), an AD (analog-to-digital converter) processor with extremely high sampling rate and accuracy is needed, which drastically increases the overall cost and limits the application of active noise reduction systems in mass-produced low-value products. Furthermore, active noise reduction systems based on adaptive filters are not very effective for low-frequency noise reduction. Also, the adaptive filters are very complex to debug in open and semi-open active noise reduction systems.

[0034] To at least partially solve one or more of the above problems and other potential problems, exemplary embodiments of this disclosure propose a noise reduction device. The noise reduction device includes multiple sound acquisition units configured to acquire the sound emitted by the noise source to be reduced and convert it into a first electrical signal; a signal amplification unit configured to superimpose the first electrical signals received from the multiple sound acquisition units and amplify the superimposed signal according to a target amplification factor to generate a second electrical signal, wherein the target amplification factor is the amplification factor corresponding to the condition that the speaker does not produce feedback; and a speaker, which is set toward the noise source to be reduced and is used to convert the second electrical signal into a sound signal. The noise reduction device can synchronize the noise reduction output signal with the input signal, thereby ensuring the noise reduction effect. In particular, the use of an analog operational amplifier can significantly improve the speed, making the noise reduction output signal synchronize with the input signal, thereby ensuring the noise reduction effect.

[0035] The following describes the scheme of the embodiment of the present disclosure with reference to the accompanying drawings.

[0036] FIG2 shows a perspective view of the noise reduction device 100 according to an embodiment of the present disclosure. FIG3 shows a side view of the noise reduction device 100 according to an embodiment of the present disclosure. FIG4 shows a bottom view of the noise reduction device 100 according to an embodiment of the present disclosure. For ease of understanding, the positive directions of the X-axis, Y-axis, and Z-axis are shown by arrows in the figure.

[0037] The noise reduction device 100 includes, for example, multiple sound acquisition units 102, a signal amplification unit 106, and a speaker 104.

[0038] The multiple sound acquisition units 102 are configured, for example, to acquire the sound emitted by the noise source 200 to be noise-reduced and convert it into a first electrical signal. The sound acquisition unit 102 is, for example, a microphone.

[0039] The signal amplification unit 106 is configured, for example, to superimpose the first electrical signals received from the multiple sound acquisition units 102, and to amplify the superimposed signal according to a target amplification factor to generate a second electrical signal. The target amplification factor is the amplification factor corresponding to the condition that the speaker does not produce feedback.

[0040] The speaker 104 is positioned, for example, toward the noise source 200 to be reduced, and is used to convert the second electrical signal into an audio signal. It should be understood that the audio signal output by the speaker 104 is used to reduce noise from the sound (e.g., noise) emitted by the noise source 200.

[0041] In some embodiments, a plurality of sound acquisition units 102 are evenly distributed relative to the radiation port 202 of the noise source 200 to be reduced, and the number of the plurality of sound acquisition units 102 is positively correlated with the size of the radiation port 202 of the noise source 200 to be reduced. For example, the larger the size of the radiation port 202 of the noise source 200 to be reduced, the more the plurality of sound acquisition units 102 are.

[0042] It is worth noting that, regarding the positional relationship between the plurality of sound acquisition units 102 and the radiation port 202 of the noise source 200 to be reduced, in some embodiments, the sound acquisition unit 102 is, for example, a directional microphone, and the sound acquisition unit 102 points in the direction of the radiation port 202 of the noise source 200 to be reduced; in some embodiments, the sound acquisition unit 102 is, for example, an omnidirectional microphone, and the rule of pointing in the direction of the sound source does not need to be followed.

[0043] It should be noted that regarding the positional relationship between the plurality of sound acquisition units 102 and the speaker 104, for example, the plurality of sound acquisition units 102 are uniformly arranged around the speaker 104 (e.g., as a noise-canceling speaker).

[0044] In some embodiments, when noise reduction is performed on a point sound source, the point sound source emits spherical sound waves. For example, the speaker 104 is placed on the side of the radiation port 202 of the noise source 200 to be noise-canceling, which is a point sound source, and the distance between the speaker 104 and the point sound source is, for example, less than 0.5 meters. The speaker 104 emits spherical sound waves, for example. The plurality of sound acquisition units 102 are arranged around the speaker 104, and the distance between the plurality of sound acquisition units 102 and the speaker 104 is, for example, about 10 centimeters. When noise reduction is performed under this setting, the spherical sound waves emitted by the point sound source neutralize the spherical sound waves emitted by the speaker 104, thereby reducing low-frequency noise.

[0045] In some embodiments, when noise reduction is performed on a surface sound source, for example, a range hood can be considered a surface sound source. A speaker 104 is arranged, for example, at the air inlet of the range hood, and multiple sound acquisition units 102 are arranged in a ring around the air inlet of the range hood. In some embodiments, the distance between the multiple sound acquisition units 102 is approximately 10 centimeters. In some embodiments, the multiple sound acquisition units 102 are evenly arranged. In some embodiments, the multiple sound acquisition units 102 can be arranged at different distances. For example, the low-frequency signal emitted by the surface sound source is neutralized by the anti-phase sound wave emitted by the speaker 104.

[0046] Taking the noise reduction device 100 as an example, it includes, for example, eight sound acquisition units 102. The radiation port 202 of the noise source 200 to be noise-reduced is, for example, square. Two sound acquisition units are arranged on each of the four sides of the radiation port 202 of the noise source 200 to be noise-reduced.Collection unit 102. Eight sound acquisition units 102 are evenly distributed at the radiation port 202 of the noise source 200 to be reduced.

[0047] It should be understood that in some embodiments, the radiation port 202 of the noise source 200 to be reduced is, for example, circular, and the multiple sound acquisition units 102 are evenly distributed relative to the radiation port 202 of the noise source 200 to be reduced.

[0048] In some embodiments, the multiple sound acquisition units 102 are evenly distributed around the radiation port of the speaker 104. For example, the multiple sound acquisition units 102 are evenly distributed around the periphery of the radiation of the speaker 104.

[0049] FIG5 shows a circuit diagram of multiple sound acquisition units according to an embodiment of the present disclosure. The eight sound acquisition units 102 correspond to eight channels, for example (e.g., first channel CN1, second channel CN2, third channel CN3, fourth channel CN4, fifth channel CN5, sixth channel CN6, seventh channel CN7, and eighth channel CN8). The sound acquisition unit 102 corresponding to each channel is electrically connected to a power supply terminal (e.g., 12V) and a ground terminal GND. Regarding the first channel CN1, the sound acquisition unit 102 outputs a first electrical signal Vin, for example, via a first resistor R1; regarding the second channel CN2, the sound acquisition unit 102 (page 4 / 11, CN 121811843 A) outputs a first electrical signal Vin, for example, via a second resistor R2; regarding the third channel CN3, the sound acquisition unit 102 outputs a first electrical signal Vin, for example, via a third resistor R3; regarding the fourth channel CN4, the sound acquisition unit 102 outputs a first electrical signal Vin, for example, via a fourth resistor R4; regarding the fifth channel CN5, the sound acquisition unit 102 outputs a first electrical signal Vin, for example, via a fifth resistor R5; regarding the sixth channel CN6, the sound acquisition unit 102 outputs a first electrical signal Vin, for example, via a sixth resistor R6; regarding the seventh channel CN7, the sound acquisition unit 102 outputs a first electrical signal Vin, for example, via a seventh resistor R7; regarding the eighth channel CN8, the sound acquisition unit 102 outputs a first electrical signal Vin, for example, via an eighth resistor R8.

[0050] FIG6 shows a circuit diagram of a signal amplification unit according to an embodiment of the present disclosure. In some embodiments, the signal amplification unit 106 includes a first amplifier 162. The inverting input of the first amplifier 162 is configured to receive a first electrical signal Vin from a plurality of sound acquisition units 102; that is, the outputs (e.g., Vin) of the plurality of sound acquisition units 102 are all electrically connected to the inverting input of the first amplifier 162. The non-inverting input of the first amplifier 162 is electrically connected to a reference voltage VREF, and the output of the first amplifier 162 is electrically connected to the inverting input of the first amplifier via a fourteenth resistor R14. The output of the first amplifier 162 is used to output a second electrical signal. The output of the first amplifier 162 is connected, for example, via a ninth capacitor C9 and a second...The eleventh resistor R21 outputs a second electrical signal.

[0051] The reference voltage VREF is, for example, obtained by voltage division of the power supply terminal voltage via the fifteenth resistor R15 and the seventeenth resistor R17. For example, the seventeenth resistor R17 is connected in parallel with the eighth capacitor C8.

[0052] The first amplifier 162 is, for example, an analog operational amplifier. It is worth noting that using an analog operational amplifier can significantly improve the speed, making the noise reduction output signal synchronized with the input signal, thereby ensuring the noise reduction effect. It should be understood that analog signals amplified by operational amplifiers for small signals have no delay. Digital signals undergo various operations, even AD (analog-to-digital conversion) and DA (digital-to-analog conversion) operations, which will have delay. Moreover, the delay problem existing in digital signal processing is a difficult problem in the active noise cancellation industry.

[0053] The target amplification factor of the signal amplification unit 106 is the amplification factor corresponding to the condition that the speaker does not produce feedback. For example, the target amplification factor is the maximum amplification factor that makes the speaker 106 not produce feedback.

[0054] For example, the target amplification factor is determined through tuning.

[0055] For example, the noise reduction device 100 is positioned relative to the device to be denoised (e.g., the noise source 200 to be denoised). For example, multiple sound acquisition units 102 are evenly distributed relative to the radiation port 202 of the noise source 200 to be denoised. Then, the noise reduction device 100 is activated to tune the noise reduction device 100 so that the amplification factor of the signal amplification unit 106 of the noise reduction device 100 is set to the target amplification factor.

[0056] In some embodiments, the amplification factor of the signal amplification unit 106 in the noise reduction device 100 is adjusted, for example, manually. It should be understood that the magnitude of the amplification factor of the signal amplification unit 106 is positively correlated with the magnitude (i.e., strength) of the sound signal emitted by the speaker 104. It should be understood that the speaker 104 plays in reverse toward the noise source 200 to be denoised, and the sound signal emitted by the speaker 104 is used to denoise the noise source 200.

[0057] For example, the amplification factor of the signal amplification unit 106 is gradually increased from an initial value (it should be understood that the initial value is a small value) until the noise reduction device 100 exhibits a howling phenomenon. Then, the amplification factor of the signal amplification unit 106 is slowly decreased until the noise reduction device 100 no longer exhibits howling. At this point, the debugging operation for the noise reduction device 100 is completed. The current amplification factor of the signal amplification unit 106 is used as the target amplification factor. Thereafter, based on this target amplification factor, the noise reduction device 100 can achieve the optimal noise reduction effect. Therefore, the target amplification factor corresponds to the maximum amplification factor corresponding to the noise reduction device 100 without howling. In some embodiments, determining whether the noise reduction device 100 exhibits howling can be done, for example, by using the human ear.

[0058] In some embodiments, the noise reduction device 100 is calibrated, for example, by automatic calibration. For example, according to the specification page 5 / 11, the noise reduction device 100 further includes a calibration unit, which includes, for example, a coefficient adjustment unit and a feedback detection unit. The coefficient adjustment unit is configured, for example, to adjust the amplification coefficient of the signal amplification unit 106 to a target amplification coefficient based on the detection result of the feedback detection unit. The target amplification coefficient is the maximum amplification coefficient that prevents the speaker from feedback. The feedback detection unit is configured, for example, to detect whether the speaker 104 is feedback.

[0059] The coefficient adjustment unit is implemented, for example, using a controller. The coefficient adjustment unit is implemented, for example, using a CPU (Central Processing Unit), MCU (Microcontroller Unit), FPGA (Field Programmable Gate Array), etc. The coefficient adjustment unit is electrically connected to the gain (i.e., amplification coefficient) control terminal of the signal amplification unit 106 to adjust the amplification coefficient of the signal amplification unit 106. It should be understood that the amplification coefficient of the signal amplification unit 106 can be adjusted by, for example, by adjusting the built-in regulator of the signal amplification unit 106. In some embodiments, the amplification factor can also be determined according to the noise reduction target.

[0060] The feedback detection unit is, for example, an audio detection device, which can receive the sound signal emitted by the speaker 104 and detect and analyze the frequency, amplitude, and other characteristics of the signal contained in the received sound signal in order to determine whether the speaker 104 is feedback. For example, when the amplitude of any frequency component of the signal contained in the sound signal detected by the feedback detection unit is greater than a predetermined amplitude threshold, it can be determined that the noise reduction device 100 is feedback. During this debugging process, the coefficient adjustment unit gradually increases the amplification factor of the signal amplification unit 106 from the initial value (it should be understood that the initial value is a small value) until the feedback detection unit detects that the noise reduction device 100 is feedback. Then, the coefficient adjustment unit slowly decreases the amplification factor of the signal amplification unit 106 until the feedback detection unit detects that the noise reduction device 100 is no longer feedback. At this point, the debugging operation for the noise reduction device 100 is completed. The current amplification factor of the signal amplification unit 106 is used as the target amplification factor. Subsequently, based on this target amplification factor, the noise reduction device 100 can achieve the best noise reduction effect. Therefore, the target amplification factor corresponds to the maximum amplification factor of the noise reduction device 100 without howling.

[0061] For example, based on the coefficient adjustment unit and the howling detection unit, a relevant debugging program can be run. The program will automatically increase the power amplifier's multiplier, that is, increase the volume. The system will automatically detect howling and then reduce the power amplifier's volume until the howling is reduced to a certain level, at which point the volume will be locked and stored, and the first round of active noise reduction debugging will be completed.In some embodiments, the debugging program can be implemented as an APP (application). In some embodiments, the adjustment of the amplification coefficient of the signal amplification unit 106 can be automatically adjusted by an external system.

[0062] For example, the howling detection unit is implemented using a main control chip. The debugging process can be run fully automatically based on the coefficient adjustment unit and the howling detection unit. The coefficient adjustment unit gradually increases the amplification coefficient of the signal amplification unit 106 from an initial value (it should be understood that the initial value is a small value). The howling detection unit (e.g., the main control chip) receives the sound signal emitted by the speaker 104 and performs FFT (Fast Fourier Transform) on the sound signal to analyze the frequency, amplitude, and other characteristics of the sound signal in order to automatically detect howling and automatically control the signal amplification unit 106. For example, when the noise reduction device 100 has not yet howled, the coefficient adjustment unit gradually increases the amplification coefficient of the signal amplification unit 106 from an initial value (it should be understood that the initial value is a small value) until the howling detection unit detects that the noise reduction device 100 no longer howls. At this point, the debugging operation for the noise reduction device 100 is completed. The current amplification factor of the signal amplification unit 106 is used as the target amplification factor. Subsequently, based on this target amplification factor, the noise reduction device 100 can achieve the optimal noise reduction effect. Therefore, the target amplification factor corresponds to the maximum amplification factor of the noise reduction device 100 without feedback.

[0063] It is worth noting that, for example, the purpose of manual adjustment is to find the maximum noise reduction amplitude of the speaker 104, which means adjusting the volume of the speaker 104 to the maximum. It should be understood that the noise reduction device 100 cannot be increased indefinitely, because this will eventually cause circuit oscillation, resulting in feedback (for example, feedback occurs when a microphone is pointed directly at a speaker in a KTV). Therefore, it is necessary to adjust the volume of the noise reduction device 100 so that it can reach the feasible maximum amplitude for noise reduction without causing system feedback.

[0064] Adjustment can be performed using, for example, two methods. The first method, for example, involves not setting a noise source, meaning the noise source is in a closed state (e.g., a range hood is off). The volume (i.e., amplification factor) is gradually adjusted to the maximum without triggering a howling sound. The second method, for example, involves setting a noise source (e.g., noise source 200 to be reduced, such as noise generated by turning on a range hood). Based on this, the amplification factor of the signal amplification unit 106 is increased to increase the volume of the speaker 104. It should be understood that the noise emitted by the noise source will be neutralized and reduced due to active noise cancellation. In this process, the volume (i.e., amplification factor) is gradually increased until it reaches the maximum without howling. In some embodiments, for example, in a quiet environment (a noise-free environment), the noise cancellation device 100 is adjusted to determine the target amplification factor of the signal amplification unit 106. It is worth noting that quiet...The environment refers to an environment where the ambient noise is below a predetermined value, such as 50 decibels. For the specific debugging process, refer to the aforementioned "manual debugging" and "automatic debugging," which will not be repeated here.

[0065] In some embodiments, the noise reduction device 100, for example, uses an analog circuit-based, digital circuit-assisted method, which significantly reduces costs while effectively controlling low-frequency broadband repetitive noise and random impulse noise.

[0066] In some embodiments, the noise reduction device 100, for example, uses a one-time production line feedback debugging method or installs a worker's handheld device (e.g., a mobile app or terminal) to debug the device feedback in one go, without requiring secondary debugging without altering the structure of the noise reduction target. The noise reduction device 100 of this disclosure is provided with multiple sound acquisition units (e.g., noise acquisition microphones), which are arranged, for example, around the noise source 200 to be reduced. The noise reduction device 100 also includes a signal amplification unit (e.g., a speaker power amplifier) ​​and a speaker (e.g., an active noise-canceling speaker). The noise reduction device 100 of this disclosure also includes, for example, a debugging unit, which can be implemented as a digital or analog volume adjustment module or a controller module. The noise reduction device 100 disclosed herein is also equipped with a wireless or Bluetooth connection module, for example. Microphone signals (e.g., signals collected by multiple sound acquisition units) near the noise source 200 to be reduced are input to a speaker power amplifier (e.g., a signal amplification unit) via signal superposition. The speaker power amplifier (e.g., a signal amplification unit) generates a second electrical signal, and the speaker plays an inverse sound wave according to the second electrical signal for active noise reduction.

[0067] It is worth noting that since the phase is played through analog circuitry, it has already been set by hardware and does not need to be repeatedly set. The amplitude of the sound played by the speaker (e.g., corresponding to the target amplification factor of the signal amplification unit) can, for example, be determined by the user before the noise reduction device 100 is used.

[0068] It is worth noting that the multiple sound acquisition units are evenly arranged (e.g., evenly distributed relative to the radiation port of the noise source to be reduced). The multiple sound acquisition units are arranged, for example, around the direction of the noise source 200 to be reduced. The first electrical signals generated by all noise sources 200 are superimposed by the signal amplification unit, amplified by the signal amplification unit 106 according to the amplification factor, and then output through the speaker 104 for noise reduction of the noise sources 200. By controlling the amplification factor of the signal amplification unit 106 (i.e., controlling the volume of the speaker 104), feedback from the noise reduction device 100 can be avoided. The more sound acquisition units 102 there are, the lower the probability of feedback, because the volume allocated to each sound acquisition unit will be smaller, thus greatly reducing the overall probability of feedback. Furthermore, if an individual sound acquisition unit malfunctions, it will not...This causes the noise reduction device 100 to malfunction, resulting in uncontrollable howling, and the active noise reduction effect will decrease by 1 / n (where n is the number of sound acquisition units 102).

[0069] The debugging of the noise reduction device 100 disclosed herein can be performed only during the first use in actual conditions. After that, as long as the overall shape does not change, no secondary debugging is required.

[0070] It is worth noting that the debugging, for example, is to adjust the actual effect of active noise reduction by changing the amplification factor (e.g., amplification factor) of the signal amplification unit 106 to achieve the optimization of the noise reduction effect.

[0071] It is worth noting that, assuming the power intensity of the noise source 200 to be denoised is X, the amplification factor of the sound acquisition unit 102 is, for example, a, and the voltage amplitude of the first electrical signal generated by a single sound acquisition unit 102 is Vin. For example, taking the setting of 8 sound acquisition units 102 as an example, X can be considered as a 8 Vin. Therefore, if only one sound acquisition unit 102 is set up, the voltage amplitude of the first electrical signal corresponding to the sound acquisition unit 102 is Vin=X / a (i.e., Vin=8 Vin at this time). Therefore, increasing the volume of the sound acquisition unit 102 will lead to the possibility of feedback. And, with only one sound acquisition unit 102, the probability of feedback increases by 8 times. Therefore, if feedback occurs before the volume required for noise reduction is reached, the noise reduction effect will be greatly reduced. Therefore, the technical solution of this disclosure uses multiple sound acquisition units 102. In addition, using multiple sound acquisition units 102 will result in more details of the sound from the noise source 200 to be reduced, which has a positive effect on the noise reduction effect. In some embodiments, the signal after the superposition of multiple first electrical signals is not filtered, but amplified by the signal amplification unit. In some embodiments, the signal after the superposition of multiple first electrical signals can be filtered and conditioned, and then amplified by the signal amplification unit.

[0072] It is worth noting that, taking the setting of 8 sound acquisition units 102 as an example, X can be considered as a 8 Vin, that is, signal superposition. It should be understood that when the signals of the 8 sound acquisition units 102 are completely consistent, the superposition will be 8 times. The 8 times here is a general expression. According to the actual situation, when there are differences between multiple sound acquisition units 102, X is the superposition of the signals of multiple sound acquisition units 102.

[0073] The noise reduction device 100 uses an analog operational amplifier, and the input and output are almost synchronous. Therefore, the noise reduction device 100 is particularly suitable for noise reduction objects with relatively small size.

[0074] Taking the noise source 200 to be reduced (i.e. the noise reduction object) in the figure as a range hood as an example, the speaker 104 is, for example, set in the range hood.The vent of the range hood serves as the radiation port for the noise source to be reduced. Multiple (e.g., eight) sound acquisition units 102 are arranged around the vent of the range hood. It should be understood that the number of sound acquisition units 102 can be adaptively adjusted according to the size of the vent of the range hood. When the signal amplification unit 106 is set to the target amplification factor, the speaker 104 emits anti-phase sound waves toward the vent of the range hood, forming a cancellation silence zone, for example, in the middle of the area corresponding to the speaker 104 and the multiple sound acquisition units 102, where the sound acquisition units 102 can only receive the sound from the noise source to be reduced. It should be understood that only when the volume of the speaker 104 is too high (e.g., when the signal amplification unit 106 is greater than the target amplification factor) will the sound emitted by the speaker 104 break through the silence zone. Thus, the sound emitted by the speaker 104 is received by the sound acquisition unit 102 (e.g., a microphone), forming a microphone howl, or microphone self-excitation. Therefore, the target amplification factor set for the signal amplification unit 106 corresponds to the maximum amplification factor that prevents the speaker from whistling, which allows the noise reduction device 100 to achieve the best noise reduction effect.

[0075] The noise reduction device 100 can be applied to noise reduction of electrical equipment such as home appliances, medical equipment, and industrial equipment, and can also be applied to noise reduction of non-pure electric mechanical equipment such as automobiles and rail transit.

[0076] FIG7 shows a block diagram of an electromechanical device 400 according to an embodiment of the present disclosure. The electromechanical device 400 includes a sound-generating device 402 and a noise reduction device 100, with multiple sound acquisition units of the noise reduction device 100 facing the sound-generating device 402. The sound-generating device 402 of the electromechanical device 400 is, for example, a device that generates noise due to vibration during the operation of the electromechanical device 400.

[0077] The electromechanical device 400 includes, for example, electrical equipment such as home appliances, medical equipment, and industrial equipment, and also includes non-pure electric mechanical equipment such as automobiles and rail transit.

[0078] In some embodiments, the electromechanical equipment includes, for example, a range hood, and the noise reduction device 100 is disposed at the vent of the range hood to reduce noise generated during the operation of the range hood.

[0079] In some embodiments, the electromechanical equipment includes a central air conditioner, and the noise reduction device 100 is disposed at the vent of the central air conditioner to reduce noise generated during the operation of the central air conditioner.

[0080] FIG8 shows a flowchart of a method 800 for noise reduction according to an embodiment of the present disclosure. Method 800 may be performed by a debugging unit or at an electronic device 900 shown in FIG9. It should be understood that method 800 may also include additional steps not shown and / or the steps shown may be omitted, and the scope of the present disclosure is not limited in this respect. Specification 8 / 11 pages 10 CN 121811843 A

[0081] At step 802, it is determined whether the noise reduction speaker is whistling.

[0082] For example, the feedback detection unit is an audio detection device that can receive the sound signal emitted by the speaker 104 and detect and analyze the frequency, amplitude, and other characteristics of the signal contained in the received sound signal to determine whether the speaker 104 is feedback. For example, when the amplitude of any frequency component of the signal contained in the sound signal detected by the feedback detection unit is greater than a predetermined amplitude threshold, it can be determined that the noise reduction device 100 is feedback; correspondingly, when the amplitude of any frequency component of the signal contained in the sound signal detected by the feedback detection unit is not greater than the predetermined amplitude threshold, it can be determined that the noise reduction device 100 is not feedback.

[0083] In step 804, in response to determining that the noise reduction speaker is not feedback, the amplification factor of the signal amplification unit is increased, and in response to determining that the noise reduction speaker is feedback, the amplification factor of the signal amplification unit is decreased until the noise reduction speaker no longer feedback, so that the current amplification factor is used as the target amplification factor of the amplification unit.

[0084] For example, the coefficient adjustment unit gradually increases the amplification coefficient of the signal amplification unit 106 from an initial value (it should be understood that the initial value is a small value) until the howling detection unit detects that the noise reduction device 100 is howling. Then, the coefficient adjustment unit slowly decreases the amplification coefficient of the signal amplification unit 106 until the howling detection unit detects that the noise reduction device 100 is no longer howling. At this point, the debugging operation for the noise reduction device 100 is completed. The current amplification coefficient of the signal amplification unit 106 is used as the target amplification coefficient. Thereafter, based on this target amplification coefficient, the noise reduction device 100 can achieve the best noise reduction effect. Therefore, the target amplification coefficient corresponds to the maximum amplification coefficient when the noise reduction device 100 does not howl.

[0085] FIG9 shows a schematic block diagram of an example electronic device 900 for implementing the noise reduction method of the embodiments of the present disclosure. As shown in the figure, the electronic device 900 includes a central processing unit (i.e., CPU 901), which can perform various appropriate actions and processes according to computer program instructions stored in read-only memory (i.e., ROM 902) or loaded from storage unit 908 into random access memory (i.e., RAM 903). The RAM 903 can also store various programs and data required for the operation of the electronic device 900. The CPU 901, ROM 902, and RAM 903 are interconnected via bus 904. An input / output interface (i.e., I / O interface 905) is also connected to bus 904.

[0086] Multiple components in the electronic device 900 are connected to the I / O interface 905, including: an input unit 906, such as a keyboard, mouse, microphone, etc.; an output unit 907, such as various types of displays, speakers, etc.; and a storage unit 908, such as a disk, optical disk, etc.The electronic device 900 may include a disk, etc.; and a communication unit 909, such as a network card, modem, wireless transceiver, etc. The communication unit 909 allows the electronic device 900 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0087] The various processes and procedures described above, such as method 800, may be executed by CPU 901. For example, in some embodiments, method 800 may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 908. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 900 via ROM 902 and / or communication unit 909. When the computer program is loaded into RAM 903 and executed by CPU 901, one or more actions of method 800 described above may be performed.

[0088] This disclosure relates to methods, apparatus, systems, electronic devices, computer-readable storage media, and / or computer program products. A computer program product may include computer-readable program instructions for performing various aspects of this disclosure.

[0089] In some embodiments, the method 800 described above can be implemented as a computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for performing various aspects of this disclosure.

[0090] The computer-readable storage medium may be a tangible device capable of holding and storing instructions used by an instruction execution device. The computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof. The computer-readable storage medium used herein is not to be construed as a transient signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0091] The computer-readable program instructions described herein can be downloaded from the computer-readable storage medium to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external device.Storage devices. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge computing devices. A network adapter card or network interface in each computing / processing device receives computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in the respective computing / processing device.

[0092] The computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information of computer-readable program instructions, which can execute computer-readable program instructions to implement various aspects of this disclosure.

[0093] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0094] These computer-readable program instructions can be provided to a processing unit of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by a processing unit of a computer or other programmable data processing apparatus, these instructions create means for implementing the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. These computer-readable program instructions may also be stored in a computer-readable storage medium that causes a computer, programmable data processing device, and / or other device to operate in a particular manner. Thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of a flowchart and / or block diagram.

[0095] Computer-readable program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more blocks of the flowchart and / or block diagram. Specification 10 / 11 pages 12 CN 121811843 A

[0096] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, segment, or part of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0097] Various embodiments of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the embodiments in the market, or to enable other those skilled in the art to understand the embodiments disclosed herein.

[0098] The above are merely optional embodiments of the present disclosure and are not intended to limit the present disclosure. Various modifications and variations can be made to the present disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present disclosure should be included within the scope of protection of the present disclosure. Instruction manual page 11 / 11 13 CN 121811843 A Figure 1 Instruction manual figure 1 / 8 page 14 CN 121811843 A Figure 2 Instruction manual figure 2 / 8 page 15 CN 121811843 A Figure 3 Instruction manual figure 3 / 8 page 16 CN 121811843 A Figure 4 Instruction manual figure 4 / 8 page 17 CN 121811843 A Figure 5 Instruction manual figure 5 / 8 page18 CN 121811843 A FIG. 6 DESCRIPTION OF THE DRAWINGS PAGE 6 / 8 OF THE SPECIFICATION 19 CN 121811843 A FIG. 7 DESCRIPTION OF THE DRAWINGS PAGE 7 / 8 OF THE SPECIFICATION 20 CN 121811843 A FIGS. 8 AND 9 DESCRIPTION OF THE DRAWINGS PAGE 8 / 8 OF THE SPECIFICATION 21 CN 121811843 A Abstract Abdominal ultrasound examination method, system and device A noise reduction device, an electromechanical device, and a debugging method The present disclosure relates to a noise reduction device, an electromechanical device, and a debugging method. The noise reduction device includes a plurality of sound collection units configured to respectively collect sound emitted by a noise source to be reduced and convert it into a first electrical signal; a signal amplification unit configured to superimpose the received first electrical signals from the plurality of sound collection units, and amplify the superimposed signal according to a target amplification coefficient to generate a second electrical signal, the target amplification coefficient being an amplification coefficient corresponding to a condition where a speaker does not produce howling;and a speaker, arranged facing the noise source to be reduced, for converting the second electrical signal into a sound signal. The technical solution of the present disclosure can synchronize the noise reduction output signal with the input signal, thereby ensuring the noise reduction effect.

Claims

1. A noise reduction device, characterized in that, include: Multiple sound acquisition units are configured to acquire the sound emitted by the noise source to be reduced and convert it into a first electrical signal; The signal amplification unit is configured to superimpose the first electrical signals received from multiple sound acquisition units, and amplify the superimposed signal according to a target amplification factor to generate a second electrical signal. The target amplification factor is the amplification factor that prevents the loudspeaker from whistling. as well as A loudspeaker, positioned towards the noise source to be reduced, is used to convert a second electrical signal into a sound signal.

2. The noise reduction device according to claim 1, characterized in that, Also includes: The coefficient adjustment unit is configured to adjust the amplification coefficient of the signal amplification unit to a target amplification coefficient based on the detection result of the feedback detection unit. The target amplification coefficient is the maximum amplification coefficient that prevents the speaker from giving feedback. as well as The feedback detection unit is configured to detect whether the speaker is whistling.

3. The noise reduction device according to claim 2, characterized in that, The coefficient adjustment unit is further configured to: increase the amplification coefficient of the signal amplification unit in response to determining that the detection result of the feedback detection unit indicates that the speaker has not given a feedback; and decrease the amplification coefficient of the signal amplification unit in response to determining that the detection result of the feedback detection unit indicates that the noise-canceling speaker has given a feedback, until the detection result of the feedback detection unit indicates that the noise-canceling speaker no longer gives a feedback, so as to use the current amplification coefficient as the target amplification coefficient.

4. The noise reduction device according to claim 1, characterized in that, Multiple sound acquisition units are evenly distributed relative to the radiation port of the noise source to be reduced. The number of sound acquisition units is positively correlated with the size of the radiation port of the noise source to be reduced. The sound acquisition units include microphones.

5. The noise reduction device according to claim 1, characterized in that, Multiple sound acquisition units are evenly distributed around the speaker's radiating port.

6. The noise reduction device according to claim 1, characterized in that, The signal amplification unit includes: The first amplifier has its inverting input configured to receive a first electrical signal from the plurality of sound acquisition units, its non-inverting input electrically connected to a reference voltage, and its output electrically connected to the inverting input via a first resistor.

7. The noise reduction device according to claim 1, characterized in that, The first amplifier is an analog operational amplifier.

8. An electromechanical device, comprising a sound-generating device, characterized in that, It also includes a noise reduction device as described in any one of claims 1 to 7, wherein a plurality of sound acquisition units of the noise reduction device are oriented toward the sound-generating device.

9. The electromechanical equipment according to claim 8, characterized in that, The electromechanical equipment includes a range hood, and the noise reduction device is installed at the ventilation opening of the range hood; or The electromechanical equipment includes a central air conditioning system, and the noise reduction device is installed at the ventilation opening of the central air conditioning system.

10. A method for noise reduction, characterized in that, The method is used in the noise reduction device as described in any one of claims 1 to 7, comprising: Determine if the noise-canceling speaker is experiencing feedback, and In response to determining that the noise-canceling speaker is not whistling, the amplification factor of the signal amplification unit is increased, and in response to determining that the noise-canceling speaker is whistling, the amplification factor of the signal amplification unit is decreased until the noise-canceling speaker no longer whistles, so that the current amplification factor is used as the target amplification factor of the amplification unit.

Images