46results about How to "Eliminate howling" patented technology

The invention discloses a control method and system of intercom talking voice gateway of broadband and narrow band fusion on android platform which comprises the set of the priority of the call app on the android platform.When users launch the voice forward from narrow band to broadband on the android platform, the gateway receives a narrow band intercom call start event and receives a broadband intercom start event after a broadband start;and at this point the direction of the gateway from narrow band to broadband and working state is connected;after receiving the narrow band intercom incoming call end event,the gateway stops the broadband intercom and sets the timed message;after receiving the broadband intercom call end event,the gateway cancels the timed message and reverts to the idle state and eliminate the end of the incoming call by the delay of timed message. The invention utilizes the gateway to connect the users of narrow band intercom of same frequency with the voices of broadband intercom of same group,which achieves the interconnection.

The disclosed auto gain volume control method for communication comprises: pre-defining voice flow state to decide in transmission for AGC and smooth transition from high pitch to silence. This invention overcomes defects of volume and voice discontinuity, and fit for video conference.

The invention relates to an onsite classroom pickup and loudspeaking system adapted to the position of a speaker. The system comprises a pickup unit, a loudspeaker array and a processing circuit, wherein the pickup unit converts obtained audio signals of the speaker into electrical signal based on the position of the speaker, the processing circuit removes noises of the electrical signals and amplifies the de-noised signals to generate driving signals, and the loudspeaker array plays sounds of the speaker according to the driving signals. The system of the invention needs only one pickup unit, the speaker can walk in the classroom to teach class needless of wearing extra devices, local environmental noises can be effectively inhibited, and the problem of howling is eliminated.

The invention belongs to the technical field of sound systems, and discloses a method and a system for eliminating microphone scream, wherein the method and the system can detect and eliminate the sound of a frequency capable of generating scream. The method comprises the following steps that: a digital processing chip generates a sinusoidal signal of one frequency point, and outputs the sinusoidal signal to a power amplifier, and a loudspeaker outputs the sinusoidal signal; the digital processing chip receives input echo signals; the digital processing chip records amplitude peaks of the echo signals input from the first time to the Nth time; if the amplitude peaks decreases orderly, and the amplitude peak of the signal input at the Nth time is not more than an amplitude threshold, the digital processing chip determines that the signal of one frequency point cannot make the microphone generate scream; otherwise, the digital processing chip determines that the signal of one frequency point can make the microphone generate scream; if the signal of one frequency point can make the microphone generate scream, the digital processing chip obtains a pre-stored wave trap coefficient of one frequency point, and performs filtering for the signal of one frequency point, thereby eliminating the echo signal of one frequency point capable of making the microphone generate scream.

The invention discloses a super wear-resistant water-lubricated bearing composite material and a preparation method thereof, belonging to the field of macromolecule sliding bearings, and aiming at providing the water-lubricated bearing composite material which is good in abrasive resistance, low in wear rate and long in service life, and the preparation method of the water-lubricated bearing composite material. The super wear-resistant water-lubricated bearing composite material is prepared from the following raw materials in parts by weight: 40-80 parts of rubber, 20-60 parts of polyurethane rubber, 4-10 parts of zinc oxide, 1-3 parts of stearic acid, 0.2-6 parts of an accelerant, 0.5-3 parts of an anti-aging agent, 0.2-8 parts of a vulcanizing agent, 20-80 parts of carbon black, 5-60 parts of polytetrafluoroethylene radiated by a gamma ray or an electronic beam, 5-30 parts of a self-lubricating agent and 5-30 parts of reinforced fibers, wherein the rubber is one or more of nitrile rubber, carboxy nitrile rubber and hydrogenated nitrile rubber. The composite material has excellent abrasive resistance, low wear rate and long service life.

The invention discloses a system and a method for eliminating echo and howling in network sound transmission. On one hand, the method for eliminating echo and howling in the network sound transmission provided by the invention comprises the following steps: desampling audio signals which are inputted from a far end in real time so as to obtain first processed audio signals; desampling mixed audio signals of sound, which is acquired by virtue of a microphone and is transmitted from a sound box, and sound which is inputted from a near end in real time so as to obtain second processed audio signals; extracting and up-sampling signals, which are related to the first processed audio signals, in the second processed audio signals in real time so as to obtain third processed audio signals; and eliminating signals, which are related to the third processed audio signals, in the mixed audio signals acquired by virtue of the microphone so as to obtain output audio signals from which echo and howling are eliminated. On the other hand, the invention provides a system for eliminating echo and howling in the network sound transmission. With the application of the method and the system provided by the invention, echo and howling in the network sound transmission can be effectively eliminated, so that audio quality is guaranteed.

The invention discloses a method and a system for reducing noise based on frequency characteristics. The method comprises the following steps: S10: acquiring a sound signal; S20: filtering the sound signal, so as to obtain a filtered signal, and decomposing the filtered signal into sound frequency domain signals; S30: acquiring a sound frequency domain which is required by a user; S40: implementing enhancement processing on a sound frequency domain signal which is required by the user, and implementing weakening processing on signals of other frequency domains, so that a playing frequency domain signal is obtained; and S50: reducing the playing frequency domain signal and playing sound. The method provided by the invention, which reduces the noise on the basis of the natural properties of the sound, is easy to implement and broad in application scope; and a voice scheme can be freely selected, so that voice delivery becomes more intuitive and valid, user perception is clearer and voice is easier to recognize.

The invention provides a C/SiC-Si3N4 friction material preparation method, which comprises: A) sequentially carrying out CVD densification and heat treatment on a C/C preform by using propylene as a carbon source and using nitrogen as a dilution gas to obtain a C/C porous matrix; B) siliconizing the C/C porous matrix by adopting an embedding method infiltration process to obtain a siliconized matrix; C) embedding the siliconized matrix into ceramic powder, and performing nitriding treatment in a nitrogen atmosphere to obtain a nitrided matrix; and D) immersing the nitrided matrix into a coating impregnation liquid, carrying out impregnation under a vacuum condition, and then carrying out curing treatment to obtain the C/SiC-Si3N4 friction material, wherein the coating impregnation liquid comprises a liquid A and a liquid B. According to the invention, the nitriding treatment process is added on the basis of the embedding method infiltration process, the friction surface is densified, the porosity is less than or equal to 5%, and the wet brake performance is attenuated by 6-13%.

Disclosed are an apparatus and a method for processing voice in a mobile communication terminal, which may prevent howling and echo between a microphone and a receiver of the mobile communication terminal. The apparatus comprises: a main chip for controlling an audio codec; a microphone; a receiver; a handsfree for performing functions of inputting and outputting the voice; an earphone jack for connecting the handsfree to the audio codec; a hall IC for generating folder on/off detecting signal by sensing whether the folder of the mobile communication terminal is opened or closed; and a switch, located in between the microphone and the audio codec, for connecting the microphone and the audio codec based on the folder on/off detecting signal generated by the hall IC and jack detecting signal indicating that the handsfree is connected to the mobile communication terminal.

The invention discloses a digital hearing-aid with a customizable functioning mode and an implementation method of the digital hearing-aid with the customizable functioning mode. The implementation method includes: (1) a microphone receiving a sound; (2) the sound entering an analog-to-digital conversion device to be converted to a digital signal; (3) on a hearing-aid software, selecting all functions according to needs, wherein the number of hearing-aid channels is an affirmatively chosen item; (4) a digital signal processor, based on digital signal processing (DSP), of the hearing-aid receiving the information of an upper layer checking and matching system and sending the information to a parameter control module; (5) a function management unit receiving the information of the parameter control module to achieve all the selected functions; (6) the signal entering a digital-to-analog conversion device to be reverted to a sound signal; and (7) a receiver receiving the signal and outputting the signal to a patient. All functions can be customized in a personalized mode according to the individual hearing loss situation of the patient and practical needs based on an identical hearing-aid, so that the purpose that various personalized hearing-aids with different functional modules are achieved is achieved, and the using is more economical, flexible and humanized.

The invention relates to the technical field of emulsifying equipment, and concretely relates to an impeller and a low-noise emulsifying pump. The impeller comprises a stator and a rotor coupled withthe stator, and at least one shear blade of the rotor and/or at least one tooth blade of the stator are/is provided with a pressure reduction channel. When a fluid is homogenized, sheared and emulsified by the stator and the rotor which are coupled with each other, the shear blade of the rotor passes through the inner and outer layers of the tooth blade of the stator, the pressure reduction channel communicates the fluid on the two sides of the shear blade and/or the fluid on the two sides of the tooth blade, the pressure difference of the fluid on the two sides of the shear blade and/or the tooth blade is reduced, squeal generated during homogenizing, shearing and emulsifying is eliminated, and friction of the material with the rotor and the stator is reduced, so sound generated when thehomogenizing and shearing emulsifying pump works is reduced.

The invention discloses a DC-DC switching power supply and an inductor squealing elimination method thereof. The switching power supply comprises a switching power supply control circuit used for generating a switching signal SW, a switching power supply output filtering circuit used for converting the switching signal SW generated by the switching power supply control circuit into a stable directcurrent voltage to be output, a voltage reduction circuit connected to the output end of the switching power supply control circuit and used for lowering the voltage of the switching signal when theswitching signal SW is high and providing a discharging access for a burr filtering circuit when the switching signal SW is low, and the burr filtering circuit connected between the voltage reductioncircuit and the ground in series and used for enabling the switching signal which is higher than a set voltage to be connected to the ground in a burr short-circuit processing manner when the switching signal SW is high, and discharging charges through the voltage reduction circuit when the switching signal SW is low. By virtue of the switching power supply, the current within the specific frequency range of the DC-DC switching power supply can be filtered out, and inductor squealing can be eliminated effectively.

The invention relates to a squeak prevention program control device for a loudspeaking system. The device comprises a microphone signal input interface, a bias amplifier circuit, an analog to digital converter, a program control module, a digital to analog converter and an audio signal output module. According to the program control module, a loudspeaker feedback signal received by a microphone is enabled to be an inverted signal through programming, a customized weak signal is dynamically removed according to a squeak analysis result, the received signal is dynamically changed to a delay value of a loudspeaker, finally, squeak is avoided, and a certain denoising effect is realized.

The invention discloses a pulse ignition circuit based on Buck principle and a gas wall-hanging furnace. The pulse ignition circuit comprises an ignition module, a flame detection module and a controller, wherein the flame detection module comprises a pulse and fire detection unit and a signal conversion module which are connected with the output end of the ignition module in sequence, and the signal conversion module is used for converting an analog signal output by the pulse and fire detection unit. A comparator is adopted to output a flame parameter signal, the I/U port connected with a flame detection signal is changed from an analog (AD) detection port to a normal detection port, and the detection signal is more accurate. Only high and low levels are arranged at a chip detection portreceiving the flame detection signal. As only the high and low levels are arranged at a flame detection end, the difficulty of hardware design and software programming is greatly reduced.

The invention discloses a vehicle rear independent main deceleration assembly. The vehicle rear independent main deceleration assembly comprises a connecting flange, a main decelerator shell, a driving tooth, a driven tooth, a differential machine assembly, and differential semi-shafts. The connecting flange is fixed to the driving tooth. The driven tooth is engaged with and fixed to the driving tooth. The differential machine assembly comprises a differential machine shell, two semi-shaft gears, and four planetary gears. The planetary gears are perpendicular to the two semi-shaft gears. Eachplanetary gear is engaged with and connected to one lateral faces of the two semi-shaft gears separately. The planetary gears are rotatably arranged in the differential machine shell. The other lateral ends of the semi-shaft gears are separately fixedly connected with the corresponding differential semi-shafts in a detachable mode. The differential semi-shafts are separately detachably fixed to corresponding tires. The driven tooth is detachably fixed to the outer edge of the differential machine shell. According to the vehicle rear independent main deceleration assembly, the structure is simple, noise during vehicle driving can be effectively reduced, the service life of the planetary gears can be effectively prolonged, torque transmission is stable, resonance is avoided, and NVH performance and riding comfort of the whole vehicle are effectively improved.

The invention relates to the field of windproof equipment, and particularly relates to a universal joint nut and a windproof supporting device for preventing clamping stagnation. A sliding base and abottom plate are connected with an output shaft of a gear motor and a gear pair, wherein the gear pair is connected with a transmission shaft through a bearing in a supported mode; the transmission shaft is connected with a lead screw through a plug pin; the lead screw is connected with a sliding column on the universal joint nut; the sliding base is fixed to the bottom plate; the sliding column is mounted in the sliding base; and the lead screw pushes the universal joint nut to slide in the sliding base. The lead screw and the sliding column are connected through the universal joint nut, thelead screw and the sliding column can relatively rotate by a certain angle, and therefore the clamping stagnation phenomenon is eliminated.

The invention relates to a high-efficiency and energy-saving furnace end, which comprises a gas and air mixing chamber, wherein the gas and air mixing chamber is positioned in a furnace cavity and communicated with a combustion tray; a ceramic plate with holes is paved on a surface layer of the furnace cavity; a combustion surface which is shaped like the bottom of a pan is formed by the ceramic plate and the combustion tray; a distance between the combustion surface and the bottom of the pan is 1.5 centimetres (cm) to 2 cm; and a water pipe is arranged below the ceramic plate and used for supporting the ceramic plate and utilizing waste heat water. Meanwhile, the invention also discloses a heating system which consists of the energy-saving furnace end. Compared with the conventional heating mode, the heating system is energy-saving.

The invention discloses a pneumatic pipe transmission system and a pneumatic pipe transmission method, relates to the field of pipe transmission systems, and solves the problems that the pneumatic pipe transmission system has complex structure and high fault rate in the prior art. The pneumatic pipe transmission system comprises a transmission pipeline. A transmitting work station and a receiving work station are arranged on the transmission pipeline. A transmitter inlet is formed at the transmitting work station, and a transmitter outlet is formed at the receiving work station. A door body is arranged at the transmitter inlet and the transmitter outlet respectively. The transmitting work station is connected with an air inlet line which is connected with an air source device. An air suction line is connected to the transmission pipeline close to the receiving work station, and is connected with the air source device. The pneumatic pipe transmission system and the pneumatic pipe transmission method are applied to the pneumatic pipe transmission.

The invention provides an air guide structure and a range hood. The air guide structure comprises air guide plates and concave-convex structures, wherein the concave-convex structures are used for changing the air inlet frequency of the air guide plates and arranged on the surfaces of the sides, facing an air inlet of a panel of the range hood, of the air guide plates. The concave-convex structures used for changing the air inlet frequency of the air guide plates are arranged on the air guide plates, so that a certain time difference exists when air passes through the concave-convex structures on the air guide plates, differentiation of air speeds is enhanced, meanwhile, the inherent frequency of the air guide structure is changed, and the air inlet area is increased. Accordingly, a squeaking phenomenon of the air guide structure, namely the whole range hood is eliminated by means of a frequency balancing method, and the operation reliability of the range hood is improved.

The invention provides an anti-howling preceding connecting line for a musical instrument. The connecting line comprises a data line and a preceding structure connected with the connecting line, wherein an input end and an output end are respectively arranged at the two ends of the data line; the preceding structure comprises a chip, a preceding audio processing circuit, a toggle switch and a power supply; the chip and the preceding audio processing circuit are connected and then connected with two wiring terminals of the toggle switch; the power supply is connected with the chip; and a positive input and a positive output of the power supply connected with the chip are respectively connected with two wiring terminals on the other side of the toggle switch. The preceding structure and theconnecting line serve as an integral structure or a split structure, so that a preceding power amplifier is omitted, the whole size is reduced, and collection and use are facilitated; connection or disconnection of the preceding structure can be controlled by the toggle switch, so that whether the preceding structure is required can be selected according to an actual condition, and the selectivityof a user is improved; and the connecting line can serve as a common connecting line for use when the power supply is powered off, so that an adaptation condition is increased.