In noisy environments such as construction sites, busy streets, or crowded public places, background noise may overwhelm voice signals, making it difficult for the receiver to understand the conversation content of the sender. Effective environmental noise reduction technology can significantly improve the clarity of intercom speech and ensure the accuracy of information transmission.
Today, we will introduce a technology for environmental noise reduction: active noise reduction technology
Active Noise Control (ANC) is a technology that reduces noise electronically. Its core principle is to use the interference characteristics of sound waves to cancel out noise by generating sound waves that are opposite in phase to noise and have the same frequency and amplitude.
The working principle of ANC technology can be summarized as the following steps:
Noise collection: Firstly, collect noise signals from the environment through a microphone.
Signal processing: Then, the processor predicts the noise situation at the next moment based on the collected noise signal and generates a phase opposite sound wave.
Sound wave emission: This phase opposite sound wave is emitted through a loudspeaker, which meets and interferes with the original noise in the air, achieving phase cancellation and reducing or eliminating noise.
Adaptive adjustment: In order to ensure the noise reduction effect, the system will use a feedback microphone to detect whether the synthesized noise has really decreased, and then adjust the processing process based on this feedback to achieve the best noise reduction effect.
ANC technology was initially applied in professional fields, such as noise cancelling headphones for pilots and airport ground crew, and has now been widely used in consumer electronics products, especially headphones and earplugs. At present, many walkie talkie manufacturers are also starting to use active noise reduction technology to improve the voice quality of walkie talkies.
Although ANC technology has achieved significant results in reducing noise, it still faces some challenges in practical applications. For example, interference terms such as bottom noise, wind noise, and impact blasting sound may affect the performance of ANC. In addition, each noise reduction application scenario has its unique acoustic characteristics, so the ANC system needs to have sufficient adaptability to calibrate for acoustic changes in individual environments.
The core algorithm of ANC technology is the Least Mean Squares (LMS) algorithm, which is an adaptive filter algorithm used to adjust the weight of the filter to minimize the mean square value of the error signal. In addition, there are other algorithms such as NLMS and FXLMS to improve the performance and stability of ANC systems.
ANC technology effectively reduces the impact of noise on people’s hearing and quality of life through advanced electronic signal processing methods. With the continuous advancement of technology and the expansion of application areas, ANC technology is expected to provide walkie talkie users with a quieter and more comfortable user experience in the future.
