Differences between Active Noise Cancellation and Passive Noise Cancellation

Passive Noise Cancellation:
Principle: Soft sound-insulating silicone materials are used to fill the ear canal. The physical structure of the headphones and special sound-insulating materials are utilized to isolate external sounds. Then, by playing sleep-aiding music, external sounds can be blocked.

Passive noise blocking is effective for high-frequency sounds, such as snoring sounds, footsteps, human voices, crying sounds, car horns, and construction noises. Because these sounds have shorter wavelengths and weaker penetrating power, they are easily blocked physically. It can effectively reduce the intrusion of external noises during sleep and can provide a relatively good noise-blocking effect. Since daily sleep scenarios are mainly in environments with high-frequency noises, passive noise-canceling headphones are more suitable for sleep sound insulation.

Active Noise Cancellation:
The principle of active noise cancellation is that the built-in microphones collect the noises in the surrounding environment, and then the processing circuit generates a sound wave that is opposite to the noise to cancel it out and neutralize the noise, thus achieving the noise-canceling effect. It is mainly targeted at low-frequency noises.

Disadvantages: There is a tendency to have background noise and ear canal pressure. Moreover, the headphones consume a relatively large amount of power. If a good noise-canceling effect is to be achieved, the headphones need to be made rather large. So they are not suitable for use during sleep.