Method for numeral sound signal processing and digital type sound frequency directional loudspeaker

Abstract

The invention discloses a digital audio directional loudspeaker and a digital audio signal processing method. An automatic gain control module adjusts the amplitude of a sound source signal; then, a filter filters out elements beyond a audio signal belt so as to reduce noises; a signal input module changes an audio analog signal into a digital signal; the processing of approximate square root algorithm or other algorithms to the audio digital signal is finished in the digital signal processing module; two state levels are output into a switch type power amplifier to match with the network to assure impedance matching; an ultrasonic transducer is used for changing an electric signal into a sound pressure signal. The ultrasonic signal which is emitted from the transducer carries the input audio signal information, does the nonlinear interaction in the air and is demodulated into audible sound. A remote control receiving unit receives orders sent by a remote control transmission unit to control parameters such as point angle, volume, transmission distance, sound effect and point sound, etc.

Description

technical field [0001] The invention relates to ultrasonic application technology, in particular to equipment and methods for making directional loudspeakers by using ultrasonic waves. Background technique [0002] In some occasions where local sound transmission is required without mutual interference between areas, such as multi-national conferences, in airplanes, restaurants, game rooms, Internet cafes, etc., it is often necessary to provide different sound services for people in different seats or areas, such as multi-national voice , background music, dialogue, etc. This requires directional speakers. Traditional directional speakers generally use audible sound surface reflection, array and other effects instead of ultrasonic waves to produce directional audible sound, which is essentially an improvement of traditional speakers, and the directivity effect is very poor. Therefore, in these occasions, considering the fear of affecting others, we have to endure the pain ...

AI Technical Summary

Problems solved by technology

This greatly reduces the conversion efficiency, and the ultrasonic transducer is a reactive load, directly loading high-frequency signals will cause the device to burn out

[0011] Therefore, under the existing conditions, the current audio frequency directional loudspeaker has a single function, imperfect supporting facilities, and is not humanized enough.

Once installed, the volume, directivity angle, sound propagation direction, sound effect processing, remote control, etc. cannot be adjusted in real time, which will bring a lot of inconvenience to users

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