Systems and methods for selecting appropriate microphone signals in multi-microphone support devices to enhance audio processing

Abstract

This invention proposes a system and method for adaptive microphone selection in a multi-microphone device, comprising: determining whether there is an echo in a first microphone input and a second microphone input. If no echo is detected, the system can directly select a default microphone. If an echo is detected, the system calculates the signal strength indices of the first and second microphone inputs. If the signal strength of both microphones is below a preset threshold, the system will still select the default microphone. If the signal strength of either microphone reaches or exceeds the threshold, the system will perform a series of calculations to select between the two microphones.

Description

Cross-references to related applications

[0001] This invention claims priority to U.S. Patent Application No. 19 / 002,204, filed on December 26, 2024. Technical Field

[0002] This invention relates generally to the field of audio processing, and more specifically to methods, computer programs, and systems for microphone selection in a device that supports multiple microphones. Background Technology

[0003] Today, an increasing number of audio processing devices (such as mobile phones, laptops, and other audio-enabled devices) are equipped with multiple microphones. These microphones enable more stable and accurate audio signal capture. Previously, devices selected microphones based on device configuration and usage scenarios, using preset methods. Multiple microphones on a device can receive drastically different audio inputs due to their varying positions and distances from other components (such as speakers). For example, on a typical smartphone, the bottom microphone, being closer to the speaker, may have an echo feedback that is 10 decibels higher than the top microphone. In most Android devices, the bottom microphone is enabled by default. While devices are equipped with acoustic echo cancellation to reduce echo interference, selecting an input signal with significantly lower echo interference will contribute to better audio quality.

[0004] Given the importance of improving audio quality, this invention provides a method and system for adaptively selecting and using a superior microphone on a device equipped with multiple microphones. Summary of the Invention

[0005] This system and method relate to the field of audio processing, primarily involving the adaptive selection of microphone signals in devices supporting multiple microphones. The system and method improve audio processing performance by reducing echo and other interference signals in recorded audio signals.

[0006] In some embodiments, a method and system for adaptive microphone selection in a multi-microphone device includes: determining whether an echo exists in a first microphone input and a second microphone input. If there is no echo, the system can directly select a default microphone; if an echo exists, the system calculates the maximum absolute energy of the first and second microphone inputs. Alternatively, other indicators that represent signal strength can be used to replace or assist in determining the maximum absolute energy.

[0007] The system can select a default microphone when the maximum absolute energy or other signal strength indicators of both the first and second microphone inputs are below the maximum absolute energy threshold. However, if the maximum absolute energy of either microphone input reaches or exceeds this threshold, the system performs a series of calculations. In some implementations, the maximum absolute energy threshold is approximately 0.05 when the input signal is normalized to the interval [-1, 1]. In most real-time communication (RTC) audio applications, the time-domain sampled values ​​of the input audio signal are represented as signed 16-bit integers, ranging from [-32768, 32767]. The threshold of 0.05 is calculated based on the sample values ​​being normalized to the range [-1, 1]. For example, 0.05 = 1,638 / 32,768. That is, all possible audio sample value ranges are normalized to [-1, 1], but it is not necessary to normalize the input audio signal value for each frame.

[0008] The above calculation may include: determining whether the maximum absolute energy input from the first microphone, multiplied by a first multiplier, is less than the maximum absolute energy input from the second microphone; and determining whether the maximum absolute energy input from the second microphone, multiplied by a second multiplier, is less than the maximum absolute energy input from the first microphone. In some embodiments, the first and second multipliers are equal, specifically taking a value of approximately 1.2.

[0009] If the maximum absolute energy input from the first microphone multiplied by the first multiplier is less than the maximum absolute energy input from the second microphone, the system will decrease the counter value. Conversely, if the maximum absolute energy input from the second microphone multiplied by the second multiplier is less than the maximum absolute energy input from the first microphone, the system will increase the counter value.

[0010] If the counter is below a negative threshold, the system can select the first microphone input. Similarly, if the counter is above a positive threshold, the system can select the second microphone input. When the counter is equal to or between the negative and positive thresholds, the system can select the default microphone.

[0011] The system can also analyze each audio frame for abnormal states: either the first or second microphone input is below a lower energy threshold, or the difference between the first and second microphone inputs exceeds a difference threshold. In some cases, the lower energy threshold is approximately 77 dB, and the difference threshold is approximately 15 dB. If abnormal states are continuously detected for a set time period (e.g., approximately 500 milliseconds), the system will revert the adaptive microphone selection method to its initial state.

[0012] It should be noted that the functions described above in this invention can be implemented individually or in combination. These and other functions of this invention will be described in more detail below with reference to the accompanying drawings. Attached Figure Description

[0013] To more clearly illustrate the present invention, some embodiments of the present invention will be described below with reference to the accompanying drawings:

[0014] Figure 1A This is an example diagram of a device supporting multiple microphones drawn according to an embodiment of the present invention;

[0015] Figure 1B This is an example block diagram of a multi-microphone enabling device drawn according to an embodiment of the present invention;

[0016] Figure 2 These are schematic diagrams of various sound waves drawn according to embodiments of the present invention;

[0017] Figure 3 This is a system block diagram illustrating adaptive selection of microphone usage according to an embodiment of the present invention;

[0018] Figure 4 This is a flowchart illustrating an example process of adaptive microphone selection according to an embodiment of the present invention;

[0019] Figure 5 This is an example process flowchart for abnormal state detection and recovery drawn according to an embodiment of the present invention;

[0020] Figure 6A and 6B This is a schematic diagram of a computer system capable of adaptive microphone selection according to an embodiment of the present invention. Detailed Implementation

[0021] This invention will be described in detail with reference to several embodiments shown in the accompanying drawings. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that some or all of these specific details may be omitted when implementing these embodiments. To avoid unnecessarily obscuring the invention, well-known technical steps and / or structures are not described in detail. The functions and advantages of the various embodiments can be more clearly understood through the following discussion in conjunction with the accompanying drawings.

[0022] The accompanying drawings will help to understand the various functions and advantages of the exemplary embodiments of the present invention. Those skilled in the art should understand that the embodiments of the present invention provided herein are merely illustrative and not restrictive. Unless otherwise expressly stated, all functions disclosed in this specification can be replaced by other functions that achieve the same or similar purpose. Therefore, other embodiments not exhaustively listed, or modifications thereof, should be considered included within the scope of the present invention as defined herein and its equivalents. It should be particularly noted that the imperative and / or sequential terms used herein (such as "will," "will not," "should," "should not," "must," "must not," "firstly," "initially," "then," "subsequently," "before," "after," "finally," and "ultimately," etc.) are not intended to limit the scope of the present invention, as the embodiments listed herein are merely exemplary.

[0023] This invention relates to a system and method for adaptively selecting microphones on a multi-microphone device based on audio signals, for improving audio processing performance. For ease of explanation, Figure 1A This is an example of a device containing multiple microphones, namely a smartphone. The illustration shows an Android device 100A, which includes a touchscreen 110, an input microphone 120 located at the top of the device, a first speaker 130 serving as an earpiece, and an infrared sensor 140. When the device is used as a handheld phone, the top speaker is typically enabled, and the speaker is usually placed close to the user's ear.

[0024] Smartphones typically include a front-facing camera 150 and one or more rear cameras (not shown). An ambient light detector and a proximity sensor 160 can be used to determine when the smart screen is activated and to assist with the camera function.

[0025] The smart device may also include an audio jack 170 or other auxiliary interfaces. Main power and data transfer ports (such as a USB-C port) may be located at the bottom of the device (not shown). These devices typically also include a bottom microphone 180 and a bottom speaker 190. The bottom speaker is typically used when the device is in speaker mode or playing music, navigation, or other outputs.

[0026] By default, most Android devices use the bottom microphone as the default input source. Because the bottom speaker is close to the bottom microphone, noticeable echo can occur when recording audio signals. Devices may employ acoustic echo cancellation technology to minimize echo, while other adaptive noise suppression techniques may also be used. In other words, the ability to adaptively select which microphone's signal to use can improve the quality of the audio signal.

[0027] It is important to note that this specification and subsequent discussion will focus on devices equipped with two microphones and how to select between these two microphones. This is not intended to limit the scope of this disclosure, but rather to clarify the invention and simplify the description. This disclosure also covers devices equipped with multiple microphone inputs. In such devices, input signals can be selected from multiple microphones, or in some cases, multiple microphone inputs can be combined into a single input signal. The trade-off and selection of which microphone to use can be performed by the recording device or the downlink device.

[0028] Figure 1B Another schematic diagram of the same recording device is shown, indicated as 100B. In the diagram, the various sub-components of the device are adapted to a central bus and communicate with each other. The screen interface 110 remains the core of the device, serving as both a display and an input device via its touch functionality. The first microphone 120 and the first speaker 130 are as previously shown. The infrared sensor 140 can comprise various types of sensors, including Bluetooth antennas, GPS antennas, or any other suitable sensor or transmitter type. One or more cameras 150 and a light sensor 160 are used for image and video acquisition. In some embodiments, an auxiliary jack and / or a main connector 170 enables the device to connect to peripheral devices, charge, and perform data transfer. The device also includes a second microphone 180 and a second speaker 190, located separately from the first speaker and the first microphone. The device also includes a processor 115 capable of analyzing input signals and selecting which microphone to use. A transmitter 125 enables the device to connect to various wireless networks, such as cellular networks, WiFi internet connections, etc. Memory 135 supports short-term caching and long-term storage of information.

[0029] Figure 2 This is a schematic diagram of various sound wave signals, generally indicated by 200, illustrating the principle of the adaptive microphone selection process. In this example diagram, the signal at 210 represents the far-end signal before playback. This is the signal played to the user through the bottom speaker. The second signal, 220, is captured from the microphone at the top of the device. Conversely, the third signal shown at 230 is captured from the microphone located at the bottom of the device (closer to the output speaker). As can be seen from this example diagram, the signal captured from the top microphone is several decibels lower than the signal captured from the bottom microphone. This significant reduction in far-end signal echo pollution, combined with acoustic echo cancellation (AEC) technology, can largely eliminate echoes, thus significantly improving signal quality compared to using the bottom microphone 230.

[0030] Figure 3A system block diagram illustrating microphone selection is shown, denoted by 300. As can be seen, recording device 320 receives input from two different microphones and can select between them. Recording device 320 also checks device blacklist information in device memory 310. The device memory may contain a blacklist mechanism that disables adaptive microphone selection in specific use cases, thus supporting stability between devices. For example, certain devices can be added to the blacklist to disable adaptive microphone selection. These blacklisted devices can be determined through practical experience, such as a defect in one of the two microphone recording devices (e.g., one microphone consistently fails to provide stable recordings), or the blacklist can be determined based on abnormal recording behavior reported by customers. The blacklist can be a pre-stored list in device memory or updated periodically when the device connects to a backend server.

[0031] The recorded signal, along with a far-end reference signal (not shown), is provided to the Acoustic Echo Cancellation (AEC) module 330. The AEC module 330 subtracts the delayed far-end reference signal received from the player 350 from the near-end audio signal from the microphone to eliminate echo interference. The AEC module 330 can automatically determine whether echo is present in the recorded signal captured by each microphone. The recording module 320 analyzes signal characteristics, such as the maximum absolute energy of the signal or other signal strength indicators, to automatically and adaptively determine which microphone to use. Detection and recovery workflows not described herein can be used to handle situations where the selected microphone malfunctions during a call. Such malfunctions may be caused by device system errors or improper user operation.

[0032] The adjusted signal is then provided to a module that analyzes ambient noise. This adaptive noise suppression (ANS) module (not shown) further adjusts the signal to eliminate ambient noise. The further adjusted signal is then provided to an automatic gain controller (AGC) 340, a closed-loop feedback adjustment circuit that regulates the relative amplification of the signal to ensure consistent volume. The system analyzes the volume difference between two recording signals from two different microphones. This information is also provided to the AGC to prevent the volume from remaining consistently low after uplink signal processing. This processing results in a clean and consistent audio signal, which can be compressed and then transmitted via an antenna and transmission circuitry (not shown). Finally, the playback signal 360 is played back by the player 350.

[0033] Transmission can be achieved via local Wi-Fi, cellular networks, the internet, or a combination of these methods. After transmission to the cloud, the signal is routed to a decoder located in the terminal / downlink device.

[0034] Figure 4 A flowchart illustrating an example of adaptive microphone selection in a dual-microphone scenario is shown, generally indicated by 400. The process begins by recording two signals, one from each microphone. Then, the AEC module determines if there is an echo in the microphone (at 405). If there is no echo, the default microphone is used, and the process ends; if there is an echo, the recording module calculates the maximum absolute value of the signal energy for the left and right channels (at 410). In this example, the top and bottom microphones of the device can be encoded as the left and right channels respectively. This naming is not intended to artificially limit the scope of the invention, but is merely to distinguish the two input near-end audio signals.

[0035] If the maximum absolute energy of both the left and right channel signals is below the threshold (415), the process can end and the default microphone can be used. Note that much of the disclosure herein focuses on maximum absolute energy. This is one measure of signal strength. In some other embodiments, other types of signal strength measures may be used. Therefore, it should be noted that all references to maximum absolute energy herein can be replaced by other signal strength measures. In some embodiments, the maximum absolute threshold is approximately 0.05. For the purposes of this disclosure, the terms “about” and “approximately” can mean any value within ±20% of the specified value.

[0036] However, if the maximum absolute energy (or other signal strength measurement) of the left and / or right channels is higher than a set threshold, the system checks whether the maximum absolute energy of the left channel multiplied by a first multiplier is less than the maximum absolute energy of the right channel (at point 420). In some specific embodiments, this multiplier is approximately 1.2, meaning the system determines whether 120% of the maximum absolute energy of the left channel is still less than the maximum absolute energy of the right channel. If so, the counter value is decremented (at point 425).

[0037] Conversely, a similar check is performed to determine if the maximum absolute energy of the right channel (or other signal strength measurement) multiplied by a second multiplier is still less than the maximum absolute energy of the left channel (at point 430). In some cases, the first and second multipliers are equal. In certain specific embodiments, both multipliers are set to approximately 1.2. If 120% of the maximum absolute energy of the right channel is still less than the maximum absolute energy of the left channel, the counter value is incremented (at point 435). The check for the maximum absolute energy level between the left and right channels in steps 420 and 430 can be repeated for each audio frame. Typically, the length of an audio frame is 10 milliseconds, 20 milliseconds, or other predetermined length. This check is repeated until channel selection is completed in the next stage selection step. The system can also periodically monitor the energy levels of the recordings from both microphones to identify potential anomalies, which will be discussed below. Figure 5 Further details.

[0038] The system then checks if the counter is below a negative threshold (at position 440). If so, the left microphone is selected for recording (at position 445). Conversely, if the counter is above a positive threshold (at position 450), the right microphone is selected for recording (at position 455). If the counter is between the positive and negative thresholds, the default microphone can be used. In some embodiments, the threshold is a preset fixed value. In other embodiments, the system can perform the above check on a predetermined number of audio frames (e.g., a set time period). For example, the system can perform echo detection on each audio frame within 500 milliseconds as described in steps 420 and 430 above, and after this time period, select a microphone based on whether the counter is positive or negative. In short, the system compares the echoes produced by the two microphones within a certain time and selects the microphone with the smaller echo.

[0039] After adaptively selecting the microphone using the above method, the system can switch to anomaly detection and recovery mode. As mentioned earlier, device malfunction and / or user error may lead to abnormal operating conditions. Figure 5 In the example flow 500 shown, the system monitors the device's operation and determines if there are any abnormalities in the recording signals of the left and right channels (at point 505). If an abnormality is detected, the microphone selection state is reset (at point 520). If the operation is normal, microphone signal selection between the two channels continues normally (at point 510). As used herein, "abnormality" means that both of the following conditions are met simultaneously: the strength of either microphone signal is below a threshold decibel, and the strength difference between the two channels is greater than a second threshold. In some embodiments, the strength threshold is approximately 77 dB, and the second strength difference threshold is set to approximately 15 dB. This check can be performed for each frame of audio. If the abnormal state persists for a preset time period, the entire microphone selection process will return to its initial state. In some embodiments, this preset time interval is approximately 500 milliseconds.

[0040] The above describes the system and method for adaptive microphone selection. The following discussion will focus on the hardware devices that can perform the above functions in real time. Figure 6A and 6B All depict a computer system, identified as computer system 600, which is suitable for implementing various embodiments of the present invention, wherein... Figure 6AThis presents one physical form of the system. It should be noted that the physical form of the computer system 600 is highly scalable; it can be a micro-device such as a printed circuit board or integrated circuit, or it can be expanded into a large system such as a supercomputer. The computer system 600 may include: a monitor 602, a display 604, a chassis 606, a blade server containing multiple storage drives 608, a keyboard 610, and a mouse 612. Medium 614 is a computer-readable medium used for data exchange with the computer system 600. Figure 6B The modular architecture of computer system 600 is illustrated. The main subsystems connected via system bus 620 include: processor 622 (also known as Central Processing Unit / CPU), adapted to storage devices (including memory 624). Memory 624 consists of random access memory (RAM) and read-only memory (ROM), where ROM is responsible for unidirectional data and instruction transfer to the CPU, and RAM supports bidirectional data transfer. Both types of memory can take the form of various computer-readable media described below. Fixed storage medium 626 works in conjunction with processor 622 via bidirectional connection, not only expanding data storage capacity but also taking the form of various computer-readable media. This medium is typically used as secondary storage (such as a hard disk) with a speed lower than main storage for storing programs and data. It should be noted that information stored on fixed storage medium 626 can be incorporated into memory 624 as virtual memory using a standard conversion method as needed. Removable medium 614 can take any of the computer-readable media forms described below.

[0041] The processor 622 also connects to various input / output devices, including a display 604, a keyboard 610, a mouse 612, and a speaker 630. Broadly speaking, input / output devices can encompass any of the following types: video display devices, trackballs, mice, keyboards, microphones, touch-sensitive displays, sensor card readers, magnetic stripe / paper tape readers, tablet computers, styluses, voice / handwriting recognition devices, biometric readers, motion sensors, EEG readers, or other computer devices. The processor 622 can also connect to other computers or telecommunications networks via a network interface 640. Using this network interface, the processor 622 can both receive and output information to the network when executing the aforementioned audio anomaly detection method. Furthermore, embodiments of the present invention can run independently on the processor 622 or collaborate with a remote CPU via a network such as the Internet to achieve distributed execution of computational tasks.

[0042] Software is typically stored in non-volatile memory and / or drive units. For large programs, their complete code may not all be loaded into memory for execution. However, it should be clarified that during software execution, the system will move it to a suitable computer-readable location for processing if necessary; for ease of explanation, this document will consistently refer to this location as "memory." Even if the software is loaded into memory, the processor will still use hardware registers to store relevant variable values ​​and improve execution efficiency through local caching (ideally). In this technical solution, when describing a software program as "implemented on a computer-readable medium," it should be understood that the program can be stored in any known or applicable location (non-volatile storage devices or hardware registers, etc.). When at least one parameter value related to the program is stored in a processor-readable register, the processor is considered "configured to execute the program."

[0043] During operation, computer system 600 is controlled by operating system software that includes a file management system, such as a disk operating system. An example of operating system software with a relevant file management system is from Microsoft Corporation in Redmond, Washington. A series of operating systems and their associated file management systems. Another example is the Linux operating system and its associated file management system. The file management system is typically stored in non-volatile memory and / or drive units, allowing the processor to perform various operations required by the operating system, including inputting and outputting data, storing data in memory, and storing files on non-volatile memory and / or drive units, etc.

[0044] Certain portions of this specification may be presented in the form of algorithms and symbolic representations of data bit manipulations in computer memory. These algorithmic descriptions and representations are the most effective way for those skilled in the art of data processing to communicate the essence of their work to others skilled in the art. As defined herein with common sense, algorithms are generally considered to be a self-consistent sequence of operations that leads to a desired result. These operations require physical manipulation of physical quantities. These physical quantities typically exist in the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and subjected to other operations. Sometimes, primarily for general purposes, these signals are referred to as bits, values, elements, symbols, characters, items, numbers, etc.

[0045] The algorithms and representations described herein are essentially independent of any particular computer or device. The program methods described herein can be implemented using various general-purpose systems, or more convenient dedicated devices can be designed to run specific embodiments. The required architectures for various systems will be illustrated in the following description. Furthermore, this technical solution does not limit the specific programming language; various embodiments can be implemented using multiple programming languages.

[0046] In alternative embodiments, the machine can operate as a standalone device or connect to other machines (via a network, etc.). In network deployments, the machine can act as a server or client device in a client-server network, or operate as a node device in a peer-to-peer (or distributed) network environment.

[0047] The aforementioned machines can be server computers, client computers, personal computers (PCs), tablets, laptops, set-top boxes (STBs), personal digital assistants (PDAs), cellular phones, iPhones, Blackberry devices, smart glasses, smart headphones, virtual reality devices, standalone processors, collaborative distributed processor systems, telephones, network devices (routers / switches / bridges), and any machine capable of executing a set of instructions (sequential or non-sequential) to perform a specific operation.

[0048] While machine-readable media or machine-readable storage media are shown as a single medium in the exemplary embodiments, "machine-readable media" and "machine-readable storage media" should be understood to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more sets of instructions. The term should also include any medium capable of storing, encoding, or carrying a set of instructions that can be executed by a machine and cause the machine to perform one or more methods of the currently disclosed technologies and inventions.

[0049] Generally, routines implementing embodiments of this disclosure may be implemented as part of an operating system or as a specific application, component, program, object, module, or sequence of instructions (referred to as a "computer program"). These computer programs typically contain one or more sets of instructions time-sharing across different storage devices of a computer (or distributed across computers), which, when read and executed by one or more processing units in the computer (or across computers), cause the computer to perform operations to implement the functions disclosed in this invention.

[0050] Furthermore, although the embodiments are described in the context of fully functional computers and systems, those skilled in the art will understand that the embodiments can be distributed as program products in various forms, and the disclosure of this invention applies equally to any specific machine or type of computer-readable medium used for actual implementation and distribution.

[0051] Although the present invention has been described through several embodiments, various changes, modifications, permutations, combinations, and equivalent alternatives still exist, all of which fall within the scope of the present invention. While subheadings have been added for ease of explanation, these headings are illustrative only and are not intended to limit the scope of the invention. Furthermore, it should be noted that there are many different implementations of the methods and apparatus of the present invention; therefore, the appended claims should be interpreted as including all changes, modifications, permutations, combinations, and equivalent alternatives that conform to the spirit and scope of the present invention.

Claims

1. A computerized method for adaptive microphone selection in a multi-microphone device, characterized in that, The computerized method includes: Determine whether there is an echo in the first microphone input and the second microphone input; If no echo is detected, select the default microphone; If an echo is detected, the signal strength of the inputs from the first and second microphones is calculated. If the signal strength input from both the first and second microphones is below the signal strength threshold, then the default microphone is selected. If the signal strength values ​​input by the first microphone and the second microphone are equal to or higher than the signal strength threshold, then calculate whether the signal strength value input by the first microphone multiplied by the first multiplier is less than the signal strength value input by the second microphone, and calculate whether the signal strength value input by the second microphone multiplied by the second multiplier is less than the signal strength value input by the first microphone. If the signal strength value input from the first microphone multiplied by the first multiplier is less than the signal strength value input from the second microphone, the counter value is decreased; if the signal strength value input from the second microphone multiplied by the second multiplier is less than the signal strength value input from the first microphone, the counter value is increased. If the counter value is below the negative threshold, the first microphone input is selected; if the counter value is above the positive threshold, the second microphone input is selected; if the counter value is equal to or between the negative and positive thresholds, the default microphone is selected.

2. The computerized method according to claim 1, wherein the signal strength value refers to the maximum absolute energy, and the maximum absolute energy threshold is approximately 0.

05.

3. The computerized method according to claim 1, wherein the first multiplier is equal to the second multiplier.

4. The computerized method according to claim 3, wherein the first multiplier and the second multiplier are approximately 1.

2.

5. The computerized method according to claim 1 further includes analyzing whether there is an abnormal state in each audio frame.

6. The computerized method of claim 5, wherein the abnormal state includes satisfying the following two conditions: the first microphone input or the second microphone input is below a lower limit energy threshold, and the difference between the first microphone input and the second microphone input is above a difference threshold.

7. The computerized method according to claim 6, wherein the lower limit energy threshold is approximately 77 dB.

8. The computerized method according to claim 6, wherein the difference threshold is approximately 15 dB.

9. The computerized method according to claim 5, if an abnormal state is continuously detected during a set time period, the adaptive microphone selection method is restored to its initial state.

10. The computerized method according to claim 9, wherein the set time period is approximately 500 milliseconds.

11. A computer system for adaptive microphone selection in a multi-microphone device, characterized in that, The computer system includes: The acoustic echo cancellation module is used to determine whether there is an echo in the input of the first microphone and the second microphone; The processor is used to select the default microphone when no echo is detected; A recorder is used to calculate the signal strength of the inputs from the first and second microphones when an echo is detected; The processor is further configured to perform the following operation: if the signal strength of both the first microphone and the second microphone input is below a signal strength threshold, then select the default microphone; The processor is further configured to perform the following operations: if the signal strength values ​​input by the first microphone and the second microphone are equal to or higher than the signal strength threshold, then calculate whether the signal strength value input by the first microphone multiplied by a first multiplier is less than the signal strength value input by the second microphone, and calculate whether the signal strength value input by the second microphone multiplied by a second multiplier is less than the signal strength value input by the first microphone. The processor is further configured to perform the following operations: if the signal strength value input from the first microphone multiplied by a first multiplier is less than the signal strength value input from the second microphone, then the counter value is decreased; if the signal strength value input from the second microphone multiplied by a second multiplier is less than the signal strength value input from the first microphone, then the counter value is increased. The processor is further configured to perform the following operations: if the counter value is below a negative threshold, select a first microphone input; if the counter value is above a positive threshold, select a second microphone input; if the counter value is equal to or between the negative and positive thresholds, select a default microphone.

12. The computer system of claim 11, wherein the signal strength value refers to the maximum absolute energy, and the maximum absolute energy threshold is approximately 0.

05.

13. The computer system of claim 11, wherein the first multiplier is equal to the second multiplier.

14. The computer system of claim 13, wherein the first multiplier and the second multiplier are approximately 1.

2.

15. The computer system of claim 11, wherein the processor is further configured to analyze whether there is an abnormal state in each audio frame.

16. The computer system of claim 15, wherein the abnormal state includes satisfying two conditions: the first microphone input or the second microphone input is below a lower limit energy threshold, and the difference between the first microphone input and the second microphone input is above a difference threshold.

17. The computer system of claim 16, wherein the lower limit energy threshold is approximately 77 dB.

18. The computer system of claim 16, wherein the difference threshold is approximately 15 dB.

19. The computer system according to claim 15, if an abnormal state is continuously detected during a set time period, the adaptive microphone selection method is restored to its initial state.

20. The computer system of claim 19, wherein the set time period is approximately 500 milliseconds.

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