Check patentability & draft patents in minutes with Patsnap Eureka AI!

Method and apparatus for eliminating acoustics echo in handless telephone communication

An acoustic echo and telephone communication technology, applied in the field of acoustic feedback prevention, can solve problems such as the inability of direct acoustic echo, achieve the effect of flexible deployment and reduce signal distortion

Active Publication Date: 2007-01-31
INST OF ACOUSTICS CHINESE ACAD OF SCI
View PDF5 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Improving the environment around the speaker can effectively suppress indirect acoustic echo, but not direct acoustic echo

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method and apparatus for eliminating acoustics echo in handless telephone communication
  • Method and apparatus for eliminating acoustics echo in handless telephone communication
  • Method and apparatus for eliminating acoustics echo in handless telephone communication

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] refer to image 3 As shown, make a device for eliminating acoustic echo in speakerphone communication, which device includes:

[0045] A signal preprocessor 1 is used to receive the voice signal from the far end, and carry out signal preprocessing (signal preprocessing) to it to generate appropriate audio energy, and reduce the voice signal distortion in the playback process of the ultrasonic transducer;

[0046] A modem 2, that is, a signal modulation module, is connected with the signal preprocessor 1 and an ultrasonic signal generator 3, and is used to modulate the amplitude of the pre-modulated audio signal onto a carrier wave of an ultrasonic frequency band, and generate The ultrasonic signal of the signal envelope (Envelope), that is, the audio envelope filling signal;

[0047] An ultrasonic signal generator 3, connected with the modem 2, for generating ultrasonic signals;

[0048] A driving amplifier 4, connected with the modem 2, has the function of amplifying...

Embodiment 2

[0063] refer to image 3 As shown, a device for eliminating acoustic echo in speakerphone communication is made.

[0064] Wherein, the transducer array of the loudspeaker 5 is not compactly arranged, but forms a circle, and the microphone 6 is placed in the circle formed by the transducer array. The transducer array and the microphone can be located on the same plane or the transducer array is slightly higher than the microphone 6, such as Figure 5shown. Of course, the speaker 5 and the microphone 6 in this embodiment can also be installed in exchange positions, but it is still ensured that the sound waves emitted by the speaker 5 are not directly fed into the microphone 6 .

[0065] Others are with embodiment 1.

Embodiment 3

[0067] refer to image 3 As shown, a device for eliminating acoustic echo in speakerphone communication is made.

[0068] Wherein, the directional loudspeaker 5 adopts a disc-shaped transducer array compactly arranged, and the transducer array of the directional loudspeaker 5 is separately configured from the microphone 6, which is arranged in a similar way to Embodiment 1 or 2, but in space There is more freedom in the design, and the speaker can also be considered as a device with decorative functions, such as being placed on the wing of the phone panel, or even facing away from the microphone. In this embodiment, the loudspeaker 5 and the microphone 6 are installed on different sides of the phone, so that the sound reproduction of the loudspeaker 5 will not be directly fed into the microphone 6, as Image 6 shown. Certainly, the speaker 5 and the microphone 6 in this embodiment can also be installed in exchange positions, but it is still ensured that the sound waves emitt...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method and device for preventing sound feedback in a hand-free telephone system, based on echo path and using ultrasonic pointing character and self-demodulation of nonlinear sound interaction to preprocess audio signal in distant place, for example, modulating audio signal amplitude to ultrasonic carrier wave and sending it out, so as to achieve the purpose of avoiding sound feedback without the help of other echo eliminating devices and methods. And the invention is suitable to eliminate the echo caused by speaker in communication system.

Description

technical field [0001] The present invention relates to a method and apparatus for preventing acoustic feedback in a hands-free telephone system. Background technique [0002] In the traditional telephone system, the existence of echo will seriously affect the quality of voice calls and the stability of the system. Generally speaking, there are two forms of echo: one is the echo caused by the impedance mismatch in the electrical connection (such as two / four-wire conversion circuit), which is called "line echo" or "network echo" (Line Echo or Network Echo). ); the second is derived from the acoustic coupling between the microphone and the loudspeaker, that is, the "acoustic echo" (Acoustic Echo) generated through the acoustic path. [0003] For the first form of line echo caused by impedance mismatch at both ends of the call, the technology of echo cancellation is becoming more and more mature, and has experienced the process of theoretical research and practical application...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H04M9/08
Inventor 杨军李晓东田静
Owner INST OF ACOUSTICS CHINESE ACAD OF SCI
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com