The difference between active noise cancelling and passive noise cancelling headphones

Noise, also known as noise, is an unwelcome sound that annoys people and nature when they hear it. Any sound that affects people's work, study and rest is called noise. The perception of noise varies depending on each person's feelings and habits, so noise is sometimes a subjective feeling. Generally speaking, people call environmental sounds that affect people's conversations or thinking noise.

Noise Cancelling Headphones Definition

Noise-cancelling headphones refer to headphones that use some method to reduce noise. Currently, there are two types of noise-cancelling headphones: active noise-cancelling headphones and passive noise-cancelling headphones.

The active noise reduction function is to generate reverse sound waves equal to the external noise through the noise reduction system to neutralize the noise, thereby achieving the effect of noise reduction. Passive noise reduction headphones mainly form a closed space by surrounding the ears, or use sound insulation materials such as silicone earplugs to block external noise.

The difference between active noise cancelling and passive noise cancelling headphones

Passive noise reduction (sound insulation and noise reduction)

In terms of noise reduction principle, passive noise reduction is to fill the ear cup with sponge to isolate noise through the ear cup and sponge. There are certain requirements for the clamping force of the ear cup. If the clamping force is small and there is a gap between the ear cup and the ear, the noise reduction effect will be much worse. Active noise reduction is to set an intelligent noise reduction chip in the ear cup. When the built-in sound pickup sensor of the headset senses external noise, the intelligent circuit will generate a sound wave opposite to the external noise to offset the noise.

In terms of price, passive noise reduction is easy to make and relatively cheap, usually only a few dozen yuan to one or two hundred yuan. Active noise reduction headphones have high technical requirements and usually cost more than a thousand yuan.

In terms of application, passive noise reduction headphones can be used as labor protection headphones in factories, construction sites and other places. Wearing noise reduction headphones while working makes it difficult to communicate with people around you. Active noise reduction headphones can block huge noises while also sensing small sounds without affecting communication. They are generally used in the military, airports and other places.

In terms of noise frequency, passive noise reduction blocks high-frequency noise. It is more suitable for some more regular noise reduction scenarios and is achieved by stacking sound insulation materials. However, it is helpless to deal with complex environments and a large amount of low-frequency resonance noise. Active noise reduction can effectively deal with noise in complex environments, such as in cars and cabins, by picking up sound through microphones. Therefore, under certain specific conditions, the advantages of active noise reduction are extremely obvious. Active noise reduction has a significant effect on eliminating low-frequency noise signals, especially noise from air conditioners, engines, etc. Ambient noise can be reduced by up to 25dB-30dB. Compared with passive noise reduction, active noise reduction is more intelligent.

In terms of sound quality, active noise reduction adds noise reduction processing signals to the original music, which will inevitably affect the purity of the music and form sound coloration. Noise reduction processing chips and pickup microphones will have errors in their work, causing some non-noise signals to be offset. This is why many users find that the sound of active noise reduction headphones lacks details and sounds dull.

Active Noise Cancellation

Summarize

Active noise reduction technology has been developed for decades and has been maturing. It is gradually extending from high-end applications to the civilian market and is applied in a variety of environments. The most fundamental reason is that compared with the material science of passive noise reduction, the processing mechanism of active noise reduction has more room for improvement. However, technology blockade is the most troublesome problem for the industry. Currently, several companies in the industry that have core active noise reduction technology will not disclose their technology. Technology blockade is obviously not conducive to the development of the industry.

But this does not mean the development of noise reduction. At present, some domestic brands have independently developed active noise reduction technology, and will vigorously promote active noise reduction headphone products this year. The environment we face is becoming more and more complex, and the environment in our lives is getting bigger and bigger. The only purpose is to make noise reduction headphones more popular and bring them to the mass consumer group.