What is ANC, ENC, CVC, DSP Noise Cancellation/Reduction of earphones?
There are so many noise reduction technologies in the market. But do you know what’s the differences? And how to avoid being cheated?
Today we’d like to tell you more about the noise reduction functions of the earphone. The function of noise reduction is very important to us. First, it is to reduce the noise and avoid over-amplifying the volume, so as to reduce the damage to our ears. The second is to filter out noise to improve sound quality and call quality.
Noise reduction can be divided into Passive Noise Reduction and Active Noise Reduction.
Passive noise reduction is also known as physical noise reduction. Passive noise reduction refers to the use of physical characteristics to isolate the external noise from the ear, mainly through the head beam of the earphone designed to be a little tighter, the earmuff cavity for acoustic optimization, the earmuff put sound absorption materials inside......And so on to achieve the earphone physical sound insulation. Passive noise reduction is very effective for isolating high frequency sound (such as human voice) and generally reduces noise by about 15-20dB.
Active noise reduction refers to the noise reduction technologies such as ANC, ENC, CVC and DSP that are featured by merchants when they publicize the noise reduction function of earphones. What are the principles of these four kinds of noise reduction and what are their functions?
The feedforward（FF） microphone is used to collect noise signals in the environment.There is a problem of sequence here: the noise is collected first, but the noise can only be reduced if the noise is produced at the same time. So the processor makes predictions based on the noise, predicts what the noise will be like at the next moment, and produces corresponding counteracting sound waves.
In order to ensure the quality of noise reduction, a feedback（FB） microphone is also needed to detect whether the synthesized noise is really reduced. Based on the feedback microphone, the processor adjusts the process to further reduce the resultant noise volume, which is called an adaptive process.
The final sound heard by the human ears is: ambient noise + inverted ambient noise. The superposition of two types of noises add up to achieve sensory noise reduction, beneficiary is yourself.
According to the position of the pickup microphone, active noise reduction is divided into feedforward active noise reduction and feedback active noise reduction.
At present, among the noise reduction TWS, Airpods pro and SONY are the best ones. ANC actively uses two MICs for noise reduction, namely, feedforward MIC and feedback MIC, and call MIC.
ENC (Environmental Noise Cancellation, Environmental Noise reduction technology),
ENC can effectively suppress 90% of the rever se environmental noise, thus reducing the environmental noise up to more than 35dB, so that game players can communicate with each other more freely. Through the array of two microphones, the speaker's speaking position can be accurately calculated to protect the speech of the main direction target while removing all kinds of interference and noise in the environment.
DSP is short for Digital Signal Processing. Mainly for high and low frequency noise. The principle is that the microphone collects the ambient noise, and then the system copies an inverted sound wave equal to the ambient noise, cancelling out the noise, so as to achieve better noise reduction effect. The principle of DSP noise reduction is similar to ANC noise reduction. However, DSP de-noising noise directly neutralizes and cancels each other in the system.
CVC (Clear Voice Capture) is a Voice software noise reduction technology. Mainly for the echo produced during the call. The full-duplex microphone noise cancellation software provides the function of echo and ambient noise cancellation, which is the most advanced noise reduction technology in the bluetooth headset now.
DSP technology (elimination of external noise) mainly benefits the headphone user, while CVC (elimination of echo) mainly benefits the other side of the call.
Hope it's useful for you.