Close-range howling-free interphone and intercom system

Abstract

The invention discloses a short-distance howling-free interphone and an intercommunication system, the short-distance howling-free interphone comprises a first device and a second device for receiving a pickup signal of the first device, and the first device comprises a shell and a microphone arranged at a central position; the shell comprises a front cavity and a rear cavity, pickup holes and air guide holes are distributed in the surfaces of the front cavity and the rear cavity respectively, the air guide holes correspond to the microphone and the pickup holes, and the front cavity, the rear cavity and the microphone jointly form the super-heart strong-directivity pickup; the second equipment comprises a shell, a circuit module and an audio output module, and the circuit module receives a pickup signal of the first equipment and an external input talkback signal and outputs the input signal after howling processing; the short-distance howling-free intercom system at least comprises two short-distance howling-free interphones which are respectively used as a host and a sub-machine. According to the invention, the interphone does not cause howling and noise interference due to echo and reverberation in a micro-close-range scene voice dialogue.

Description

technical field [0001] The invention relates to the field of walkie-talkie technology, in particular to a short-distance non-howling walkie-talkie and a walkie-talkie system. Background technique [0002] Currently, in an audio device, due to factors such as a collection method of the audio device, there is howling in the collected audio signal. For example, in a sound reinforcement system, the audio signal received by the microphone is amplified by the power amplifier and then output by the speaker, and the output signal may be received by the microphone again after reflection and / or refraction, forming a positive feedback loop. According to the Nyquist stability criterion, some frequency points may produce uniform oscillations, resulting in the continuous increase of the power of the audio signal of the public address system, the system is unstable, and the phenomenon of acoustic feedback may occur. As a result, the audio device emits unpleasant sounds, and the audio sign...

AI Technical Summary

Problems solved by technology

The voice played at the receiving end may be fed back to the intercom sending end to form a voice loop, causing self-excitation, which in turn leads to howling

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