Do you yearn for a peaceful place of your own in this noisy world? Noise, this invisible invader, not only disrupts our daily rhythm, but also quietly erodes our physical and mental health. But don't be afraid, the advancement of technology has brought us noise reduction technology - this unparalleled martial art of defeating noise. Today, let's unveil its mysterious veil together and experience the tranquility and comfort brought by noise reduction technology!
1. Noise reduction technology, its initial charm
What is noise reduction technology? Simply put, noise reduction technology is a technique that improves sound quality by reducing or eliminating unwanted sounds.
It is mainly used in fields such as headphones, surveillance cameras, and communication engineering. Whether it's audio, video, communication, or image processing, noise reduction technology can make our lives clearer and more peaceful.
2. The evolutionary history of noise reduction technology
The development of noise reduction technology, from passive to active, and then to intelligent, is like a fascinating evolutionary history.
Passive Noise-Cancelling
Passive noise reduction is the initial noise reduction technology that reduces the sound entering the ear through physical isolation or sound-absorbing materials.
There are usually three noise reduction measures used, namely noise reduction at the sound source, noise reduction during propagation, and noise reduction at the human ear. Just like the earplugs or earmuffs we wear in noisy environments, they reduce noise at the human ear through physical means.
Although passive noise reduction has a simple principle and good control effect on mid to high frequency noise, its noise reduction effect on low frequency noise is not ideal.
Speaking of which, let me briefly introduce high-frequency noise and low-frequency noise to you.
High frequency noise: with a frequency higher than 1000 Hz, usually comes from small objects that are moving or vibrating rapidly. The characteristic is poor penetration power, which will significantly attenuate as the propagation distance increases or when encountering obstacles, such as computer cooling fans.
Low frequency noise: frequencies below 400 Hz, usually related to vibrations or mechanical movements of large equipment. The characteristics are long propagation distance, strong penetration power, and no significant changes with distance, such as airplane sound.
Active Noise Cancellation (ANC)
With the leap of electronic technology, active noise reduction technology has emerged. The inspiration for active noise reduction technology comes from the phase cancellation effect.
The phase cancellation effect refers to the phenomenon where the phase difference between the direct wave and the reflected wave received by the positioning device at the receiving antenna of the positioning point reaches 180 °, and the two signals cancel each other out, resulting in the positioning signal being zero or lost.
Active Noise Cancellation (ANC) is a technique that uses electronic circuits to reverse the phase of the original noise, thereby canceling each other out when sound waves are superimposed.
This technology starts from the noise source itself and processes the noise signal through electronic circuits to make it opposite in phase to the original noise, thereby achieving the effect of noise reduction. This technology allows us to enjoy tranquility in various noisy environments.
AI noise reduction
Entering the era of intelligence, noise reduction technology is becoming more user-friendly.
AI denoising is a method that utilizes artificial intelligence technology to identify and eliminate noise in audio.
This technology, through deep learning and neural network models, can more effectively identify and eliminate noise while reducing the detail loss that traditional denoising methods may cause.
The working principle of AI denoising is mainly to use deep learning technology to construct denoising models and conduct massive corpus training, in order to separate the original signal and noise and effectively suppress various noises. Usually divided into three steps:
This technology can not only deal with sudden non-stationary noise, but also greatly ensure the restoration of sound and improve the call experience.
In image processing, AI denoising can recognize and eliminate noise information in images. Compared to traditional methods such as mean denoising, AI denoising can more effectively identify noise and reduce the loss of details caused by smearing noise.
3. Colorful applications of noise reduction technology
Audio field: the revolution of headphones and sound systems
Noise cancelling headphones and speakers have become standard in our daily lives. Whether on airplanes, subways, noisy streets or offices, they can create a peaceful auditory environment for us.
Transportation field: new experiences of driving and riding
Automakers have also introduced noise reduction technology into their cars to reduce interference factors such as engine noise, road noise, and wind noise. Some high-end models are equipped with active noise reduction systems, allowing drivers and passengers to enjoy a quieter and more comfortable journey.
Industry and Architecture: The Shield for Guarding Hearing Health
In the industrial and construction fields, noise reduction equipment is indispensable. They not only protect the hearing health of workers, but also enhance the comfort of the working environment. Meanwhile, in public places and commercial buildings, noise reduction equipment also creates a more private and comfortable space for us.
Home field: Guardian of peaceful life
Noise cancelling headphones, silent air conditioning, noise cancelling curtains... These home noise cancelling devices are gradually becoming a part of our lives. They not only reduce the interference of external noise, but also create a peaceful and harmonious home environment for us.
