A method for shielding microphone of smart device

Abstract

The present invention discloses a method for shielding the microphone of a smart device, comprising the following steps: applying any one or a combination of aerodynamic interference and high-frequency modulated mechanical wave interference to the microphone pickup hole; performing aerodynamic interference by driving the diaphragm of the microphone pickup hole to generate additional vibration to apply interference; performing high-frequency modulated mechanical wave interference by changing the vibration state of the diaphragm of the microphone pickup hole to apply interference; until the voice information contained in the microphone pickup recording signal cannot be identified. During the process of the recording device picking up and recording human voice, the present invention causes the vibrating plate of the acoustic-electric sensor to generate random vibrations, which is equivalent to superimposing an interference on the output electrical signal domain. Due to this interference, the voice signal cannot be filtered, separated, or restored, or various voice recognition technologies cannot be used to identify and extract voice information, effectively achieving the function of shielding the microphone of the smart device from eavesdropping and recording.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing housings and accessories of communication equipment, and particularly relates to a method for shielding a microphone of an intelligent device. Background Art

[0002] Smart devices such as mobile phones have become essential items in everyone's life. They are important tools for communication, entertainment, social interaction, life and even production. With the increasing intensity of military, political and commercial espionage activities supported by high-tech means, smartphones are an important carrier and medium for espionage activities. More and more targeted Trojans, viruses and other high-tech software are maliciously installed on users' smartphones. When users are talking with others, the microphones are illegally activated to "monitor" and record the conversations, which in turn causes the user's voice information to be eavesdropped and recorded, and then artificial intelligence technology, voice recognition technology and big data technology are used to illegally obtain personal information, commercial information and secrets related to national security, resulting in the leakage of state secrets, commercial secrets and personal privacy, which leads to serious information security risks.

[0003] The security issue of eavesdropping or recording can be circumvented without affecting the communication function through the manufacturing technology of the casing or structural components of the electrical equipment.

[0004] There are many methods for shielding microphone recording. They can be divided into software control method and hardware method. They can be divided into active interference method and passive shielding method. The common methods are summarized as follows:

[0005] 1. The co-frequency noise masking method uses hardware shielding for active shielding, using audio devices and programs to generate pseudo-random noise to mask speech. The advantage is a wide coverage area, but the disadvantage is that it will produce audible noise pollution, the equipment cannot be miniaturized, and the interference may be cracked and separated. 2. The far-field ultrasonic interference method uses hardware shielding for active shielding, using ultrasound as a carrier to modulate the interference signal, and then uses an ultrasonic transducer for far-field direction playback to interfere with microphone recordings. The advantage is no audible noise, but the disadvantages are high power, narrow shielding range, ultrasonic waves are harmful to the human body, and the device is large and not portable. 3. The electromagnetic interference method uses hardware shielding for active shielding, using high-frequency electromagnetic waves to interfere with recording equipment. The advantage is no audible noise, but the disadvantage is that this method uses electromagnetic waves in a far-field manner to interfere with recording equipment within a certain range. Therefore, this method has a high transmission power, which increases the damage to human health caused by electromagnetic wave radiation; the power devices and transmitter devices are large and not portable; this method is only effective for old analog recording equipment. 4. Security software method: This method uses software shielding for active shielding, using high-privilege software to manage unauthorized recording behavior of smart device microphones. The advantages are no hardware cost and the shielding period does not affect device use. The disadvantage is that it requires the cooperation of the operating system and is prone to vulnerabilities. 5. Physical shielding method: This method uses hardware shielding for passive shielding, using sound-insulating materials to physically enclose smart mobile devices to prevent microphone recording. The advantage is that it only reduces the recording sound, which can be restored by technical means. The disadvantage is that the device is heavy and has poor mobility. The phone cannot be used during the shielding period, requiring a high degree of user cooperation. 6. Dedicated security chip: This method uses hardware shielding for active shielding, using a built-in dedicated chip to independently control the microphone power supply, which can be forced to shut down when necessary to prevent the microphone from recording beyond its permission. The advantages are high security and the most thorough shielding. The disadvantage is that this function must be reserved at the beginning of the device and requires support from a dedicated security chip, which may be ineffective due to hacker attacks. Summary of the Invention

[0006] The purpose of the present invention is to address the problems in the above-mentioned prior art and provide a method for shielding the microphone of a smart device. The method can be achieved by directly installing accessories on the smart device. It has the characteristics of small size, low power consumption, no radiation, and no audible noise. It can also complete active shielding of microphone recording without the need for operating system cooperation or the use of a dedicated security chip.

[0007] In order to achieve the above object, the present invention has the following technical solutions:

[0008] A method for shielding a microphone of a smart device comprises the following steps:

[0009] Applying any one or a combination of aerodynamic interference and high-frequency modulated mechanical wave interference to the microphone pickup hole;

[0010] Perform aerodynamic interference by driving the diaphragm of the microphone pickup hole to generate additional vibrations to apply interference;

[0011] Perform high-frequency modulated mechanical wave interference, applying interference by changing the vibration state of the diaphragm of the microphone pickup hole;

[0012] Until the voice information contained in the microphone recording signal cannot be recognized.

[0013] As a preferred embodiment of the method of the present invention, the application of aerodynamic interference includes the following process:

[0014] Airflow generation, for generating pressure airflow;

[0015] Air flow conveying, used to achieve the distribution and transmission of pressurized air flow;

[0016] The air flow jet is used to connect the pressurized air flow with the atmosphere, and the pressurized air flow flows through the diaphragm surface of the microphone pickup hole. The pressurized air flow causes changes in the air pressure on both sides of the diaphragm during the friction with the diaphragm surface, causing the diaphragm of the microphone pickup hole to vibrate abnormally, thereby interfering with the microphone's ability to pick up voice signals at the same time.

[0017] Furthermore, as a preferred embodiment of the method of the present invention, the pressure airflow generated by the airflow generation process is positive pressure or negative pressure, and the pressure of the airflow can be adjusted; the direction of the pressure airflow transmitted during the airflow delivery process can be selected in both directions and distributed through the airflow channel.

[0018] Furthermore, as a preferred embodiment of the method of the present invention, the airflow injection process gives the airflow direction, pressure and shape, which stimulates the microphone diaphragm to produce random mechanical vibrations, so that the microphone output signal waveform exceeds the maximum sound pressure limit after analog-to-digital conversion, forming a saturated clipping of the waveform.

[0019] As a preferred embodiment of the method of the present invention, the application of high-frequency modulated mechanical wave interference includes the following process:

[0020] High-frequency modulated electrical signal generation, used to generate a true random electrical signal waveform, and use the true random electrical signal waveform to linearly or nonlinearly modulate the high-frequency signal to obtain an electrical signal modulated waveform;

[0021] Energy conversion, for converting the electrical signal modulated waveform into a mechanical wave capable of propagating in the air;

[0022] Mechanical wave emission is used to transmit the mechanical wave to the microphone pickup hole and give the mechanical wave a certain direction, beam width and focus, thereby interfering with the vibration state of the diaphragm of the microphone pickup hole.

[0023] Furthermore, as a preferred embodiment of the method of the present invention, the frequency range of the true random electrical signal waveform is 0 to 20 KHz, and the frequency range of the high-frequency signal is higher than 20 KHz.

[0024] Furthermore, as a preferred embodiment of the method of the present invention, the high-frequency signal is a periodic signal.

[0025] Furthermore, as a preferred embodiment of the method of the present invention, the energy conversion process converts the electrical signal modulated waveform into a mechanical wave that can propagate in the air through a transducer.

[0026] Furthermore, as a preferred solution of the method of the present invention, the transducer adopts any one or more combinations of piezoelectric ceramic ultrasonic probes, piezoelectric MEMS ultrasonic transducers, and capacitive MEMS ultrasonic transducers.

[0027] As a preferred solution of the method of the present invention, aerodynamic interference and high-frequency modulated mechanical wave interference are applied to the microphone pickup hole according to the specific position, size, direction and layout of the microphone pickup hole; and human-computer interaction and perceptual feedback are also included in the process of applying aerodynamic interference and high-frequency modulated mechanical wave interference to the microphone pickup hole.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] The present invention is applicable to various smart devices such as mobile phones and can be used with smart devices at any time. It can prevent the leakage of confidential information without affecting the normal use of the equipment. Most recording devices now use acoustic sensors to collect voice signals. Common acoustic sensors are various types of microphones. For example, the microphones commonly used in smart mobile devices are silicon micromachined (MEMS) microphones. The propagation of sound is a mechanical wave that is propagated in the air by vibration. The acoustic sensor collects signals by sensing this vibration. What the present invention embodies is that when the recording device picks up and records human voice, the vibrating plate of the acoustic sensor generates random vibration, which is equivalent to superimposing an interference in the output electrical signal domain. If the voice signal cannot be filtered, separated or restored due to this interference, or if various voice recognition technologies cannot be used to identify and extract effective voice information, then the function of shielding the microphone of the smart device from eavesdropping and recording is effectively achieved.

[0030] Furthermore, the present invention selectively applies aerodynamic interference and high-frequency modulated mechanical wave interference based on the specific location, size, orientation, and layout of each microphone pickup port. These two forms of interference can act independently or collaboratively on a single recording device to achieve optimal interference. The present invention's method is a hardware-implemented active near-field shielding method with low power consumption, no electromagnetic or ultrasonic radiation, and no audible noise. It does not require intelligent device operating system software or a dedicated chip built into the device design. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 Flowchart of a method for shielding a microphone of a smart device according to an embodiment of the present invention;

[0033] Figure 2 Flowchart of a method for applying aerodynamic interference according to an embodiment of the present invention;

[0034] Figure 3 Flowchart of a method for applying high-frequency modulated mechanical wave interference according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, but not all of the embodiments.

[0036] Based on the embodiments of the present invention, ordinary technicians in this field can make some simple modifications and improvements without making any creative work. All other embodiments obtained are within the scope of protection of the present invention.

[0037] References to "embodiments" in this disclosure mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the disclosure. The appearance of such phrases in various locations in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] The present invention proposes a method for shielding the microphone of a smart device, which can be implemented through some relatively simple physical hardware. This hardware can be integrated into accessories of the smart mobile device. It has the characteristics of small size, low power consumption, no radiation, and no audible noise. It can also complete the active shielding of microphone recording without the cooperation of the operating system or the use of a dedicated security chip.

[0039] See also Figure 1 , a method for shielding a microphone of a smart device, comprising the following steps:

[0040] Applying any one or a combination of aerodynamic interference and high-frequency modulated mechanical wave interference to the microphone pickup hole;

[0041] Perform aerodynamic interference by driving the diaphragm of the microphone pickup hole to generate additional vibrations to apply interference;

[0042] Perform high-frequency modulated mechanical wave interference, applying interference by changing the vibration state of the diaphragm of the microphone pickup hole;

[0043] Until the voice information contained in the microphone recording signal cannot be recognized.

[0044] See also Figure 2 In an optional embodiment, applying aerodynamic interference includes the following process:

[0045] Airflow generation, for generating pressure airflow;

[0046] Air flow conveying, used to achieve the distribution and transmission of pressurized air flow;

[0047] The air flow jet is used to connect the pressurized air flow with the atmosphere, and the pressurized air flow flows through the diaphragm surface of the microphone pickup hole. The pressurized air flow produces aerodynamic phenomena in the process of friction with the diaphragm surface, causing changes in the air pressure on both sides of the diaphragm, causing the diaphragm of the microphone pickup hole to vibrate abnormally, thereby interfering with the microphone's pickup of voice signals at the same time.

[0048] Furthermore, the system for applying aerodynamic interference may include an airflow generation system, an airflow delivery system, and an airflow injection system. The airflow generation system, the airflow delivery system, and the airflow injection system are specifically as follows:

[0049] The airflow generating system is connected to one end of the airflow delivery system. The airflow generating system generates the air pressure required by the system at the connection end with the airflow delivery system. The air pressure can be positive or negative, and the air pressure can generate airflow within the airflow delivery system. The airflow generating system is composed of an airflow generating device. The airflow generating device can include but is not limited to fans of various forms and volumes, air pumps, and other devices that generate airflow by rotating blades or non-rotating methods. The airflow generating system can also include an airflow generation adjustment interface for externally adjusting the size of the generated airflow. The system can also include an energy supply device for providing energy for the operation of the system (including but not limited to an electrical energy interface, batteries, and other energy supply devices).

[0050] The airflow delivery system consists of airflow channels. The airflow can be delivered in both directions, depending on whether the airflow generation system generates positive or negative pressure at the port connected to the airflow delivery system. The airflow is distributed and delivered to the air injection system through the airflow channels.

[0051] The air injection system is located at the other end of the air transmission system. This end contains an open port connected to the atmosphere, usually located near the microphone pickup port. Its function is to impart specific direction, pressure, and shape to the air jet ejected from this port or the air drawn in. The air injection system is designed so that the airflow conditions entering and exiting the nozzle maximize the random mechanical vibrations of the microphone diaphragm. This excitation is typically caused by aerodynamic phenomena such as turbulence, eddies, and laminar flow, which can arise when air flows through the microphone's sound pickup port or non-smooth surfaces. This causes rapid changes in air pressure across the microphone diaphragm, resulting in abnormal vibrations of the diaphragm, masking the diaphragm vibrations caused by simultaneous speech (or other information-carrying sounds). This effectively blocks recordings at the microphone's electrical signal output. Because the diaphragm vibrations caused by aerodynamic phenomena are truly random, the sound-blocking effect is unbreakable. Furthermore, when the amplitude of this random vibration is sufficiently large, it often causes the microphone output signal waveform to exceed the maximum sound pressure limit after analog-to-digital conversion, resulting in saturation and clipping of the waveform. This severe nonlinear distortion can destroy speech signals across the entire frequency band, rendering the recorded speech signal unrecognizable by AI-based speech recognition systems or even human speakers, thus ensuring extremely high security.

[0052] See also Figure 3 In an optional embodiment, applying high-frequency modulated mechanical wave interference includes the following process:

[0053] High-frequency modulated electrical signal generation, used to generate a true random electrical signal waveform, and use this waveform to linearly or nonlinearly modulate the high-frequency signal to obtain an electrical signal modulated waveform;

[0054] Energy conversion, for converting the electrical signal modulated waveform into a mechanical wave capable of propagating in the air;

[0055] Mechanical wave emission is used to transmit the mechanical wave to the microphone pickup hole and give the mechanical wave a certain direction, beam width and focus, thereby interfering with the vibration state of the diaphragm of the microphone pickup hole.

[0056] Furthermore, the system for applying high-frequency modulated mechanical wave interference may include an interference generation system, a transducer system, a mechanical wave transmission and emission system, and the interference generation system, the transducer system, the mechanical wave transmission and emission system are specifically as follows:

[0057] The interference generation system includes a power supply module and a high-frequency modulated electrical signal generation module. The interference generation system generates a true random electrical signal waveform in the frequency range of 0 to 20 kHz, and uses the waveform to linearly or nonlinearly modulate the high-frequency signal (square wave or sine wave with a frequency higher than 20 kHz, or other periodic signals) and then outputs the electrical signal waveform to the transducer system.

[0058] The transducer system is responsible for converting the modulated waveform of the electrical signal output by the interference generation system into a mechanical wave that propagates in the air, and transmitting it to the near end of the mechanical wave transmission and emission system without leakage. The transducer system may include various possible devices, systems, and components that can convert electrical signals into mechanical waves. For example, the system may include, but is not limited to, piezoelectric ceramic ultrasonic probes, PMUTs (piezoelectric MEMS ultrasonic transducers), CMUTs (capacitive MEMS ultrasonic transducers), and other mechanical wave transducers with different characteristics, sizes, and power consumption. The transducer system may include one or more identical or different transducers.

[0059] The mechanical wave transmission and emission system is connected to the transducer system at the proximal end and one or more mechanical wave outlets near the microphone being interfered with at the distal end. A closed conduit, which can be zero length, is used between the proximal and distal ends to conduct the mechanical waves without leakage. The mechanical wave transmission and emission system transmits the mechanical waves input by the transducer system to the vicinity of the microphone to be interfered with. At the distal mechanical wave outlet, the mechanical waves are given specific characteristics such as direction, beam width, and focus, with the design goal of maximally interfering with the microphone diaphragm vibration.

[0060] The above-mentioned near-field aerodynamic interference system and near-field high-frequency modulated mechanical wave interference system can act separately on a recording device to be interfered with, or can act in a coordinated and superimposed manner on the same recording device to be interfered with. That is, near each microphone pickup hole to be interfered with, there can be an airflow jet outlet (one or more) of the near-field aerodynamic interference system and a mechanical wave transmission and emission system far-end mechanical wave outlet (one or more) of the near-field high-frequency modulated mechanical wave interference system. The application of the near-field aerodynamic interference system and the near-field high-frequency modulated mechanical wave interference system can be selected according to the specific position, size, direction, and layout of each microphone pickup hole to achieve the purpose of optimizing the interference effect.

[0061] As an optional implementation, a human-computer interaction system can also be set up, which is responsible for providing human-computer interaction and perception feedback functions such as system switching, adjustment, and light indication, presence detection, and entry detection.

[0062] The present invention utilizes the principles of aerodynamics and aeroacoustics to achieve the purpose of shielding the microphone recording by using controlled airflow to induce turbulence, eddies, or vibrations in the air near a close-range microphone, thereby driving the diaphragm to produce additional vibrations. High-frequency mechanical waves modulated with audible noise can also be used to interfere with the vibration of the microphone diaphragm in a near-field (close-range) manner to achieve the same effect. This method has extremely low power consumption, no electromagnetic or ultrasonic radiation, no noise pollution, and does not require the cooperation of smart device operating system software or a built-in dedicated chip. It also has the advantage of miniaturization, making it possible to integrate the hardware into accessories for smart mobile devices, and does not affect the normal use of the device when the shielding function is turned on. Because the diaphragm vibration caused by aerodynamic phenomena is truly random, the sound shielding effect is theoretically unbreakable and has extremely high security. At the same time, this method has the potential to cause severe nonlinear distortion to the sound recorded by the microphone, making it impossible for speech recognition systems based on artificial intelligence technology to recognize it, and it is also impossible for manual recognition to recognize it.

[0063] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for shielding a microphone of a smart device, characterized in that: The following steps are involved: Applying any one or a combination of aerodynamic interference and high-frequency modulated mechanical wave interference to the microphone pickup hole; Perform aerodynamic interference by driving the diaphragm of the microphone pickup hole to generate additional vibrations to apply interference; Perform high-frequency modulated mechanical wave interference, applying interference by changing the vibration state of the diaphragm of the microphone pickup hole; Until the voice information contained in the microphone recording signal cannot be identified; The application of the aerodynamic interference includes the following process: Airflow generation, for generating pressure airflow; Air flow conveying, used to achieve the distribution and transmission of pressurized air flow; Air jet is used to connect the pressurized air flow to the atmosphere. The pressurized air flow flows through the diaphragm surface of the microphone pickup hole. The friction between the pressurized air flow and the diaphragm surface causes changes in the air pressure on both sides of the diaphragm, causing the diaphragm of the microphone pickup hole to vibrate abnormally, thus interfering with the voice signal picked up by the microphone at the same time. The airflow injection process imparts direction, pressure, and shape to the airflow, thereby stimulating the microphone diaphragm to generate random mechanical vibrations, causing the microphone output signal waveform to exceed the maximum sound pressure limit after analog-to-digital conversion, resulting in saturation clipping of the waveform. The application of the high-frequency modulated mechanical wave interference includes the following processes: High-frequency modulated electrical signal generation, used to generate a true random electrical signal waveform, and use the true random electrical signal waveform to linearly or nonlinearly modulate the high-frequency signal to obtain an electrical signal modulated waveform; Energy conversion, for converting the electrical signal modulated waveform into a mechanical wave capable of propagating in the air; Mechanical wave emission, used to transmit the mechanical wave to the microphone pickup hole and give the mechanical wave a certain direction, beam width and focus, thereby interfering with the vibration state of the diaphragm of the microphone pickup hole; The energy conversion process converts the electrical signal modulated waveform into a mechanical wave that can propagate in the air through a transducer.

2. The method for shielding a microphone of a smart device according to claim 1, characterized in that: The pressure airflow generated in the process of airflow generation is positive pressure or negative pressure, and the pressure of the airflow can be adjusted; the direction of the pressure airflow transmitted in the process of airflow delivery can be selected in both directions and distributed through the airflow channel.

3. The method for shielding a microphone of a smart device according to claim 1, characterized in that: The frequency range of the true random electrical signal waveform is 0-20 KHz, and the frequency range of the high-frequency signal is higher than 20 KHz.

4. The method for shielding a microphone of a smart device according to claim 1 or 3, characterized in that: The high-frequency signal is a periodic signal.

5. The method for shielding a microphone of a smart device according to claim 1, characterized in that: The transducer adopts any one or more combinations of piezoelectric ceramic ultrasonic probes, piezoelectric MEMS ultrasonic transducers, and capacitive MEMS ultrasonic transducers.

6. The method for shielding a microphone of a smart device according to claim 1, characterized in that: It also includes the process of applying aerodynamic interference to the microphone pickup hole and high-frequency modulated mechanical wave interference to perform human-computer interaction and perceptual feedback.

Images