Noise reduction is quite important when design headphones, it focuses on noise reduction to avoid excessive volume which will cause damage to users’ ears. Besides,this function also filters noise to improve sound quality and call quality.
Noise reduction can be divided into two types: passive noise reduction and active noise reduction.
Passive noise reduction, that is, physical noise reduction, it refers to the use of physical characteristics to isolate external noise from ears,such as tight-design headphone head beam, optimize the acoustics of ear mask cavity,applying sound-absorbing material inside the earmuff etc.
Passive noise reduction is very effective for isolating high frequency sound (such as human voice).The noise can be generally reduced to about 15×20 dB.
Active noise reduction like ANC or CVC is the main selling point when sellers promote their headphone.Today let’s figure out their working principles and differences between CVC and ANC.
CVC(Clear Voice Capture) is a cellphone-software noise reduction technology. It mainly deals with the echo produced when making phone call. It is the most advanced noise reduction technology in Bluetooth headphones, providing echo and ambient noise cancellation functions by full duplex microphone noise canceling software.
ANC (Active Noise Control) The microphone collects external environmental noise, and then the system transforms itself into an inverse sound wave and add it to the end of horn.Finally, the sound we hear is the reverse ambient noise with environmental noise, the superposition of these two noise achieves sensory noise reduction.
To sum up, both ANC and CVC feature themselves with effective function of environmental noise canceling,but their beneficiaries are individually different:the former beneficiaries are users themselves while the latter one are the hearers.