49results about How to "Prevent echo" patented technology

The invention discloses an audio transmission delay measuring method and system. The method comprises performing synchronization operation on transmission of an original audio codebook to be measured between a transmitting end and a receiving end to obtain the transmission starting indicating information, the transmission ending indicating information, the receiving starting indicating information and the receiving ending indicating information of the original audio codebook; enabling the transmitting end to respond to the transmission starting indicating information and transmit the original audio codebook to be measured to the receiving end and to respond to the transmission ending indicating information and stop transmitting the original audio codebook to the receiving end, and enabling the receiving end to respond to the receiving starting indicating information and collect the original audio codebook transmitted by the transmitting end and to respond to the receiving ending indicating information and stop collecting the original audio codebook transmitted by the transmitting end; obtaining audio transmission delay according to the testing audio codebook collected by the receiving end and the original audio codebook prestored in the receiving end. The audio transmission delay measuring method and system solves the problem of inaccurate computation of audio transmission delay in the prior art.

The ear pad according to the present invention has a number of gathered sound-insulating walls (12) monolithically provided on an outer periphery of the basic body (11) made of an elastic material such as rubber, for instance, a silicon rubber or such as soft synthetic resins, for instance, polypropylene in a ring form with a prescribed space in the axial direction and made of the same material as that for the basic body. With this feature, the ear pad according to the present invention can provide softness and adaptability to be set in an auditory meatus without stimulating sensitive portions thereof.

The invention provides an ultrasonic phased array rapid full-focusing imaging detection method based on defect pre-positioning. The ultrasonic phased array rapid full-focusing imaging detection methodcomprises the steps of performing plane wave and full-matrix capture data collection on a target imaging area; carrying out coarse discretization processing on an imaging target imaging area, carrying out phase shift processing on the plane wave echo signal data set to obtain a plane wave imaging result, and carrying out pixel value analysis processing on the plane wave imaging result; carrying out defect positioning analysis on a plane wave imaging result through threshold processing, carrying out fine discretization processing on pixel points containing defects, and carrying out phase shiftprocessing on a full-matrix echo signal data set to obtain pixel values of the pixel points containing the defects; performing interpolation and amplification coefficient processing on unselected pixel points in the plane wave imaging result, and filling the corresponding grids with the pixel points; and obtaining a final imaging result. According to the method, an ultrasonic phased array plane wave algorithm and a full-focusing algorithm are combined, the time resolution is improved while the spatial resolution is kept, rapid ultrasonic phased array imaging detection is carried out on a component, and defects are effectively evaluated.

The invention relates to the field of communication and discloses a PSTN teleconference sound mixing method. The method includes the following steps that S1, voice active state monitoring is carried out on each member participating a conference, and the members in the voice active state are added into a sounding mixing list or a backup list; S2, updating is carried out on the sound mixing list at regular intervals; S3, gain adjustment is carried out on voice frequency of each member in the sound mixing list; S4, sound mixing is carried out, sound mixing results are output to each member participating the conference, for the member participating the conference which exists in the sound mixing list, output after the gain adjustment of the member is removed from sound mixing results and then outputting is conducted while for the member participating the conference which does not exist the sound mixing list, the sound mixing results are output. By means of the PSTN teleconference sound mixing method, influences on effects by echoes and background noise are reduced, conference quality is effectively improved; the number of sound mixing at the same time is increased, overflowing of mixed sound is avoided, and meanwhile, the volume of the sound will not be changed suddenly; the effect of conference clipping is improved, the difficulty of clipping is avoided, and frequent switching is avoided.

The invention relates to the security control technology of intelligent equipment and discloses an application hiding control method. The method comprises the first step of determining a target application to be hidden, the second step of transmitting a broadcast message representing that the target application is deleted, and the third step of intercepting an access instruction of a starter process to the target application and correspondingly returning a null value to the process of the starter for the target application so as to hide a shortcut icon of the target application in the starter. Furthermore, the method can include the following supplementary steps of determining a hidden target application to be displayed and transmitting a broadcast message representing that the hidden target application is added so as to display a shortcut icon of the target application in the starter. By means of the method, the application program can be hidden in the starter, and follow-up normal running of the application program is not influenced. The application hiding control method can be applied to an Android operating system and can also be applied to an operating system environment provided with a similar framework or mechanism.

An active delay device in a streaming media transmission system based on a universal series bus is provided and comprises a transmission delay determining unit, an actuating delay determining unit, an intrinsic delay determining unit, an intrinsic delay, a comparator, an active delaying arrangement unit, an active delay value, wherein the intrinsic delay is used for calculating each terminal device according to the transmission delay and the actuating delay, and the active delay value is used for determining each terminal device according to a maximum intrinsic delay value and the intrinsic delay of each terminal device. The terminal devices which need to perform control commands in the same frequency can accurately be synchronized, or each terminal device can perform each action according to strict time intervals, particularly in a sound mixing system, the fact that each terminal device strictly performs displaying of sound mixing signals at the same time is effectively ensured, and echo is prevented from being generated.

The invention discloses an obstacle avoidance detecting device for an electric power inspection unmanned aerial vehicle, comprising a radar detection module and a connecting structure provided on thetop cover of the unmanned aerial vehicle. The radar detection module is fixed to the unmanned aerial vehicle by the connecting structure on the top cover of the unmanned aerial vehicle. The radar detection module comprises a radar bottom cover (6), a first probe connector (5) and a radar mounting bracket (4). A probe mounting groove is formed in the center of the upper surface of the radar bottomcover (6). The first probe connector (5) is provided in the probe mounting groove and penetrates through the lower surface of the radar bottom cover (6). A plurality of protruding claws (7) located around the first probe connector (5) are provided on the lower surface of the radar bottom cover (6). The first probe connector (5) is electrically connected to the millimeter wave conversion board (2).According to the obstacle avoidance detecting device for an electric power inspection unmanned aerial vehicle, the propellers of the obstacle avoidance detecting device interfering the radar echoes due to vertical mounting, and the detection precision of the obstacle avoidance detecting device is greatly improved.

The invention discloses an array radar signal transmitting and receiving method under a radio frequency shielding signal. The idea of the invention includes the following steps: transmitting signals by a local side radar, determining interference signals in the signals transmitted by the local side radar, constructing an objective function and solving the objective function, obtaining an optimal detection signal matrix in the signals transmitted by the local side radar, and then simultaneously transmitting the optimal detection signal matrix and the interference signals in the signals transmitted by the local side radar in a radar signal transmitting antenna network, obtaining a radar detection echo signal with low interference after an opposite side target reflects the signals, receivingthe radar detection echo signal with low interference by a radar signal receiving antenna network, fusing and accumulating the received radar detection echo signal with low interference to obtain thefused and accumulated radar detection echo signal, and performing pulse compression processing on the fused and accumulated radar detection echo signal to further obtain the location of the opposite side target, wherein the location of the opposite side target is an array radar signal transmitting and receiving result under the radio frequency shielding signal.

The invention discloses a single carrier radar communication integrated signal implementation device based on phase jitter, and belongs to the technical field of radar communication. The single carrier radar communication integrated signal implementation device based on phase jitter is suitable for solving the problem that the distance sidelobe level of a radar signal in an integrated signal is too high, and can complete radar detection and communication. The single carrier radar communication integrated signal implementation device based on phase jitter includes a radar transmitting terminal,a communication receiving terminal and a radar receiving terminal, wherein the radar transmitting terminal is used for acquiring an optimal integrated signal matrix hat{S}opt<,> of Ns communication sequences, and the thinking of the single carrier radar communication integrated signal implementation device based on phase jitter includes the steps: acquiring a communication data stream, dividing the communication data stream into Ns communication sequences, and calculating an integrated signal of the Ns communication sequences, wherein Ns is a positive integer greater than 1; according to theintegrated signal of the Ns communication sequences, calculating the autocorrelation sidelobe level vector of the integrated signal of the Ns communication sequences; according to the autocorrelationsidelobe level vector of the integrated signal of the Ns communication sequences, constructing a target optimization function of the Ns communication sequences; and optimizing the target optimizationfunction of the Ns communication sequences to obtain an optimal integrated signal matrix hat{S}opt<.> of the Ns communication sequences.

An object of the invention is providing a method and device for packet acoustic echo cancellation. The echo cancelling device obtains one or more source voice packet streams in a multi-party call, selects packets from the one or more source voice packet streams so as to obtain a broadcasted stream corresponding to the multi-party call, cancels echo in a target packet stream corresponding to the broadcasted stream based on a reference packet stream corresponding to the broadcasted stream, so as to obtain the echo-cancelled packet stream corresponding to the target packet stream, and finally broadcasts the echo-cancelled packet stream to participants in the multi-party call. Compared with the prior art, the present invention realizes packet acoustic echo cancellation for a multi-party call, reduces the buffer consumption, channel allocation and corresponding overheads of maintenance and signaling for packet acoustic echo cancellation, enhances the performance of packet acoustic echo cancellation, and makes the performance of packet acoustic echo cancellation independent of the number of participants.

By the present invention are disclosed a method for providing and a method for obtaining voice call related information from a first party device (100) to a second party device (200), prior to establishing a voice call between the first party device (100) and the second party device (200). Portable communication devices (100, 200, 500) for providing and obtaining of voice call related information also disclosed. The methods comprises sending/obtaining in real time the voice call related information (steps 304, 402) from the first party device (100) to the second party device (200) over a packet switched network, and sending/obtaining a call setup message (steps 308, 410) over a circuit switched network, of the voice call from the first party device (100), so that the voice call related information can be presented to a user of the second party device (200) before responding to the call setup message.

The invention discloses an echo-preventing wall board. The echo-preventing wall board comprises a perlite board, wherein the perlite board is internally provided with a plurality of cavities; the cavities are arranged along the width direction of the perlite board and are uniformly distributed in the height direction of the perlite board; a honeycomb-shaped supporting piece is arranged on one face of the perlite board; a plurality of micro-pores which are communicated with the cavities are formed in one face, which is provided with the honeycomb-shaped supporting piece, of the perlite board; sound absorption materials are stuck on the inner wall and the bottom face of the honeycomb-shaped supporting piece; the cavities of the perlite board are internally filled with sound absorption materials; a magnesium oxychloride cement board is arranged on the other face of the perlite board; one faces, which are far away from each other, of the honeycomb-shaped supporting piece and the magnesium oxychloride cement board are provided with a first decorative face layer and a second decorative face layer. According to the echo-preventing wall board, the combination of the honeycomb-shaped supporting piece, the cavities of the perlite board and the sound absorption materials is sufficiently utilized to effectively absorb and attenuate sound waves so that the aim of preventing echoes is realized.

A method and apparatus are disclosed for canceling acoustic echo generated during transmission of text information in a communication system supporting a TTY/TDD service. When an mobile-to-land call is established between a mobile subscriber and a PSTN subscriber, a decoder notifies an encoder of detection of TTY/TDD text in a BS vocoder. The encoder then transmits a packet having silence information, which prevents acoustic echo reproduction of the text in the TTY/TDD device.

The invention discloses a group session-based audio playing method and device, a group session-based equipment management method and device and computer equipment, and belongs to the field of audio data processing. In the group session process based on the cloud technology, an audio watermark is added to to-be-played audio data, and the audio watermark is associated with a device identifier of a terminal, so that the audio watermark can indicate which terminal the audio data is played, and when other terminals collect the audio data, which terminals are located in the same space can be determined according to the audio watermark, and the subsequent equipment management,such as equipment muting or earphone access, of a user is facilitated. Audio played by a loudspeaker of a certain terminal is prevented from being repeatedly collected by microphones of other terminals in the same space, and echo and howling are prevented from being generated in the session process. And the session quality of the group session is improved.