Patent Application
20230218261
The present application is based on, and claims priority from, Taiwan Patent Application Serial Number 111100799, filed Jan. 7, 2022, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present invention relates to a noise reduction, more specifically, a method of noise reduction for an intelligent network communication.
Conventional technologies of background noise cancellation are mostly used in telephone communication or headphones. The main purpose of these technologies is to prevent the impact of background noise or ambient noise on communication quality or sound quality of headphone. At present, most of the common technologies of background noise cancellation used by intelligent devices based on voice interaction are derived from the existing technologies of traditional telephone communication. These technologies include spectral subtraction, Wiener filtering and adaptive noise cancellation.
The method of spectral subtraction is to use the mean value of amplitude of speech segmentation to subtract the amplitude of non-speech segmentation to obtain the mean value of noise, and then eliminate the noise. This method has a poor effect for unsteady noise, which is easy to cause speech distortion by noise elimination, and resulting in the decline of speech recognition rate.
The method of Wiener filtering uses the transfer function of Wiener filter to convolute the mean value of noise amplitude with the amplitude of speech segmentation to obtain the amplitude information of signal by noise elimination. It does not cause serious speech distortion in Wiener filtering method, and can effectively suppress the noise with small change range or stable in the environment. However, this method estimates the mean value of noise by calculating the statistical average of the power spectrum of noise during the silent period. This estimation is based on the premise that the power spectrum of noise does not change much before and after the sound producing. Therefore, in the case of unsteady noise with large changes, this method cannot achieve higher noise reduction performance.
Another cancellation method of ambient noise commonly used in smart devices is adaptive noise cancellation method by a directional microphone. This method uses an omnidirectional microphone to collect ambient noise, a directional microphone to collect user voice, and then adaptive noise cancellation is performed for the two signals to obtain pure voice signals.
In addition, most machines or electronic equipment often produce noise during operation. For example, with the rapid development of air conditioning technology, it has been widely used in various industrial technologies and fields. The well-known air conditioning system has a compressor as the operation core, and the most important work in the system is the transfer of heat. When the compressor operates by the rotating shaft and the refrigerant is discharged, it is easy to produce vibration and noise. Although there are some means for reducing the noise, it is still unable to eliminate the noise. In order to achieve a good suppression of the noise generated during the operation of the machine or electronic equipment, the present invention has been disclosed.
Based on the above-mentioned, the method of noise reduction for intelligent network communication has become an important work in many fields. For example, a database of noise reduction parameters or noise reduction levels of various noise sources are established to facilitate flexible adjustment of noise reduction levels, improve the performance of noise reduction to achieve the purpose of the present invention.
The purpose of the present invention is to provide a noise reduction device and method for improving the performance of noise reduction, especially a device for detecting heart sound. If the device is close to the body near the heart, the sound receiving device may receive the noise generated by the friction sound of clothes, which may affect the correct interpretation of signal or data.
According to one aspect of the present invention, the mixed audio signal includes an inverse noise of ambient noise. When the input noise pattern/waveform signal (inverse noise) and the noise source enter the ear canal of human together, the inverted noise and the noise source will produce destructive interference because of mutual cancellation of the waveform, so as to achieve the performance of reducing the noise decibel. By using the recursive method to limit the frequency step by step, the noise generated by the noise source can be effectively suppressed to improve the performance of noise reduction. It should be understood that the inverse noise can completely offset the noise of the noise source, and can also partially offset the noise of the noise source.
According to another aspect of the present invention, a smart noise reduction device is provided, which comprises a control device. A noise pattern recognizer is coupled to the control device, identifying a noise signal generated through a noise source received by a sound receiver. A noise pattern database is coupled to the control device, wherein the noise pattern database includes at least one audio type, each audio type having a plurality of preset noise pattern signals. A noise filter is coupled to the control device, destructively interfering the noise signal with a selected one of the plurality of preset noise pattern signals to reduce a noise decibel value generated by the noise source.
According to one aspect of the present invention, a speaker is coupled the control device to output the noise signal. An application (APP) is coupled to the control device, wherein the index of target noise reduction level is set in the application (APP).
According to another aspect of the present invention, the plurality of preset noise patterns generate a noise reduction parameter library and the noise reduction parameter library includes a plurality of indexes of noise reduction level and noise reduction parameters.
According to yet another aspect of the present invention, a smart noise reduction device is provided, which comprises a control device. An audio pattern recognizer is coupled to the control device, identifying an audio mixed signal received by a sound receiver, wherein the audio mixed signals include a first regularity pattern signal and a non-regularity pattern signal. An audio pattern database is coupled to the control device, wherein the audio pattern database includes at least one audio type, each audio type having a plurality of preset second regularity pattern signals. A noise filter is coupled to the control device, destructively interfering the audio mixed signal with a selected one of the plurality of preset second regularity pattern signals to produce an approximate noise, and destructively interfering the approximate noise with the audio mixed signals to produce the first regularity pattern signal.
According to an aspect of the present invention, a heart sound sensing device is provided, which comprises a control device. A heart sound pattern recognizer is coupled to the control device, identifying a heart sound mixed signal received by a sound receiver, wherein the heart sound mixed signals include a first regularity pattern signal and a non-regularity pattern signal. A heart sound pattern database is coupled to the control device, wherein the heart sound pattern database includes a plurality of preset second regularity heart sound pattern signals. A heart sound filter is coupled to the control device, destructively interfering the heart sound mixed signal with a selected one of the plurality of preset second regularity heart sound pattern signals to produce an approximate noise, and destructively interfering the approximate noise with the heart sound mixed signals to produce the first regularity heart sound pattern signal.
According to another aspect of the present invention, a wireless transmission device is coupled to the control device such that data of the heart sound patterns database can be received from a remote server or a remote device through the wireless transmission device. An analog-to-digital converter is coupled to the control device such that the heart sound pattern can be converted into a digital heart sound signal.
According to another aspect of the present invention, a warning device is coupled to the control device which can prompt the user's heartbeat status and heartbeat frequency data.
According to another aspect of the present invention, a computer program/algorithm is used to select the preset second regularity heart sound pattern signal corresponding to the first regularity pattern signal.
Some preferred embodiments of the present invention will now be described in greater detail. However, it should be recognized that the preferred embodiments of the present invention are provided for illustration rather than limiting the present invention. In addition, the present invention can be practiced in a wide range of other embodiments besides those explicitly described, and the scope of the present invention is not expressly limited except as specified in the accompanying claims.
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Referring to
The index of target noise reduction level may be received through the wireless transmission device 112. In one embodiment, the index of target noise reduction level is set in the application (APP) 118 of the noise reduction device 100 which is transmitted to the wireless transmission device 112 through the wireless network. The noise pattern database 106 is integrated into the APP 118. For example, the wireless networks include various wireless specifications, such as Bluetooth, WLAN, WiFi, etc. The index of target noise reduction level is used to determine the target noise reduction level and the target noise reduction parameter corresponding to the target noise reduction level. The target noise reduction parameters are that match the noise level generated by the noise source. In other words, the inverse noise obtained after processing based on the target noise reduction parameters can offset the noise generated by the noise source to the greatest extent.
In one embodiment, the opening or closing the function of noise reduction is controlled by the noise reduction APP 118 of the smart noise reduction device 100, and the target noise reduction level is set by the APP 118, which is suitable for different noise levels generated by various noise sources. For example, the user can select an appropriate noise reduction level for the noise source by adjusting a noise reduction level adjuster of the APP 118 to achieve the best performance of noise reduction. In other words, the best performance of noise reduction can be achieved by adjusting the noise reduction level to correct the noise difference. The index value of noise reduction level is related to the noise level.
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The message of the preset heart sound pattern (AL) is transmitted to the heart sound filter 308 by the control device 302. In order to obtain the actual heart sound signal, after selecting the preset heart sound pattern/waveform (AL) through the control device 302, the heart sound filter 308 filters the preset heart sound pattern (AL) signal from the mixed signal (X) as a noise signal (N). Then, the heart sound filter 308 filters out the noise signal (N) from the mixed signal (X) as the actual heart sound pattern (AA). That is, the actual phonocardiogram (AA) is equal to (mixed signal X) subtracting (mixed signal X subtracting preset heart sound pattern signal AL). In another embodiment, the actually received heart sound pattern/waveform (AR) is equal to (mixed signal X plus target heart sound pattern signal AL) subtracting (mixed signal X). The above operations are processed by using the principle of destructive interference of sound waves.
In one embodiment, data of the HSP database 306 may be received from a remote server or a remote device through the wireless transmission device 312. In another embodiment, the HSP database 306 may also be stored in the storage device 314.
The above-mentioned processes include identifying the mixed signal (X) by the HSP recognizer 304, selecting the target heart sound pattern (AL) corresponding to the mixed signal (X) by the control device 302, and subtracting the noise signal (N) from the mixed signal (X) by the heart sound filter 308. The actual heart sound pattern/waveform (AA) can be obtained by the above three steps, and the heart sound filter 308 outputs the actual heart sound pattern/waveform (AA) to the analog-to-digital converter 316. After conversion by the analog-to-digital converter 316, the actual heart sound pattern (AA) can be converted into a digital heart sound signal that conforms to a predetermined frequency range. That is, an analog heart sound signal conforming to a predetermined frequency range is output after the heart sound filter 308 filters out the noise signal not within a predetermined frequency range. In one embodiment, the working frequency range of the heart sound is 20 Hz to 1000 Hz, and the sound signal is output by an analog signal. The analog-to-digital converter 316 receives a filter signal of the heart sound filter 308 to obtain an analog heart sound signal with a predetermined frequency range, converts it into a digital heart sound signal conforming to the predetermined frequency range, and outputs it to the control device 302. In one embodiment, the analog-to-digital converter 316 may be built-in or external to the control device 302.
In the method of heart sound sensing, first, the heart sound sensing device 300 is placed close to the user's heart to capture an analog heart sound signal. Generally speaking, the signal waveform detection is to analyze whether the waveform of the user's cardiac signals includes a first heart sound (cardiac) signal S1 and a second heart sound (cardiac) signal S2 with a signal strength less than that of the first heart sound (cardiac) signal S1. However, if the second heart sound signal S2 is not detected, the test results of this method will not be affected, so the second heart sound signal S2 is not a necessary test condition. A dynamic detection threshold is added to analyze the first heart sound signal S 1. This dynamic detection threshold will automatically adjust the detection threshold based on the intensity change of the background noise and the previous peak intensity value of the first heart sound signal, so as to accurately determine the peak intensity of the first heart sound signal. In this embodiment, the envelope waveform is obtained by capturing the envelope of the signal, and it is compared whether the envelope waveforms of the first heart signal S1 and the second heart signal S2 in the section are continuous and the same. Then, the signal pulse detection is to analyze whether the heartbeat frequency of the heart sound signals is between 40 and 300 times per minute, analyze the peak time difference of two adjacent first heart sound signals, calculate the heartbeat frequency per minute based on the peak time difference, and distinguish the first heart sound, find the peak intensity and occurrence time of the first heart sound by using the dynamic threshold method, and thereby calculating the heartbeat frequency per minute.
The control device 302 operates and processes the digital heart sound signal conforming to the predetermined frequency range output by the HSP recognizer 304 to obtain the peak intensity and time value of the first heart sound, records the signal-to-noise ratio value at each measurement location, compares the signal-to-noise ratio value and outputs an optimal measurement location, calculates the user's heartbeat frequency per minute, and outputs the heartbeat frequency value per minute. The control device 302 may have a built-in or external memory device. The recording device receives the digital heart sound signal conforming to the operating frequency and records it in the storage device 314. The warning device 318 receives the value of the digital heart sound signal output by the control device 302 to prompt the user's heartbeat status and heartbeat frequency data. For example, if the heartbeat frequency data is abnormal received by the warning device 318, the abnormal heartbeat frequency data may be transmitted to an external device through the wireless transmission unit 312. In another embodiment, the warning device 318 may be a light emitting diode (LED) or a buzzer to indicate an abnormal heartbeat condition.
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The smart noise reduction devices 100, 300 are configured to communicate with external devices, which may be external computing devices, computing systems, mobile devices (smart phones, tablets, smart watches), or other types of electronic devices.
External devices include computing core, user interface, Internet interface, wireless communication transceiver and storage device. The user interface includes one or more input devices (e.g., keyboard, touch screen, voice input device), one or more audio output devices (e.g., speaker) and/or one or more visual output devices (e.g., video graphics display, touch screen). The Internet interface includes one or more networking devices (e.g., wireless local area network (WLAN) devices, wired LAN devices, wireless wide area network (WWAN) devices). The storage device includes a flash memory device, one or more hard disk drives, one or more solid-state storage devices and/or cloud storage devices.
The computing core includes processors and other computing core components. Other computing core components include video graphics processors, memory controllers, main memory (e.g., RAM), one or more input/output (I/O) device interface modules, input/output (I/O) interfaces, input/output (I/O) controllers, peripheral device interfaces, one or more USB interface modules, one or more network interface modules, one or more memory interface modules, and/or one or more peripheral device interface modules.
The external device processes the data transmitted by the wireless transmission device 112, 312 to produce various results.
As will be understood by persons skilled in the art, the foregoing preferred embodiment of the present invention illustrates the present invention rather than limiting the present invention. Having described the invention in connection with a preferred embodiment, modifications will be suggested to those skilled in the art. Thus, the invention is not to be limited to this embodiment, but rather the invention is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation, thereby encompassing all such modifications and similar structures. While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made without departing from the spirit and scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 111100799 | Jan 2022 | TW | national |
