A digital anti-noise module based on DSP chips and featuring a unique software anti-noise algorithm achieves a speech clarity of no less than 98% in a 120-decibel noise environment. This module has been successfully applied in our country's aerospace airborne communication equipment and industrial explosion-proof public address broadcasting and call systems.

Summary:

The current third-generation anti-noise product in China utilizes Dynamic Noise Reduction (DNR) technology. DNR technology dynamically adjusts the output voice switch by changing the voice peak, thereby achieving noise reduction. Although it is currently a good anti-noise analog processing technology, it has limitations, including dropout of light tones and trailing noise of loud sounds; the noise reduction effect is biased towards low frequencies; and it is entirely implemented through hardware circuits, making debugging and maintenance more troublesome. Due to these issues, the extensive promotion and application of analog DNR noise reduction products are limited. With the rapid development of digital signal processing technology, digital anti-noise technology products supported by digital signal processors and related algorithms have emerged continuously, replacing the DNR analog noise reduction technology products. Digital anti-noise technology applies modern digital signal processing (DSP) technology and its high-speed real-time processing capabilities, using corresponding software algorithms to process voice and noise in high-noise environments, completing voice communication functions in high-noise conditions.

The performance advantages of this digital noise reduction module include:

The software utilizes adaptive filtering algorithms, with the digital anti-noise processor typically suppressing noise by over 50 decibels. Additionally, the output speech is smooth, free from dropped words and noise tailing.

b) The digital anti-noise processor achieves balanced noise reduction across the entire voice frequency band (300-3000Hz).

c) The digital anti-noise processor can meet various anti-noise requirements by altering software algorithms, facilitating product upgrades and replacements.

d) Hardware costs are lower compared to analog DNR products.

e) By utilizing software encryption technology, the product is less susceptible to infringement and counterfeiting, thereby benefiting the interests of the manufacturers.