Table of Contents
1. Why noise cancellation is important
2. Passive noise reduction
3. How ENC works
4. How active noise cancellation works
5. Feed-forward ANC – the sensor microphone is on the outside
6. Feedback ANC – the sensor microphone is inside
7. Hybrid-ANC – Inner and outer microphones
8. Nayin ENC/FF ANC TWS/Hybrid ANC TWS
1.Why noise cancelaltion is important
The noise cancelling function is very important for the earphones. One is to reduce noise and avoid excessively amplifying the volume, thereby reducing damage to the ear; the other is to filter noise to improve sound quality and call quality.
2.Passive noise reduction
Noise cancellation can be divided into passive noise reduction and active noise reduction: Passive noise reduction is physical noise reduction. Passive noise reduction refers to the use of physical characteristics to isolate external noise from the ear. Silicon eartips have the passive noise reduction function. Passive noise reduction is very effective for the isolation of high-frequency sounds (such as human voices), and generally reduces the noise by about 15-20dB.
3.How ENC works
ENC (Environmental Noise Cancellation, environmental noise reduction technology) can effectively suppress 90% of the reverse environmental noise, thereby reducing the environmental noise up to more than 35dB, allowing gamers to communicate more freely. Through the dual microphone array, the caller’s speaking position is accurately calculated, while protecting the target voice in the main direction, and removing various interference noises in the environment.
4.How active noise cancellation works
The component that technically removes noise from the audio signal is the ANC controller, which is supported by one or more microphones as sensors. Of course, the ANC controller does not detect the noise directly from its source, but at appropriate frequencies with which noise perceived by us is transmitted. These interfering frequencies are stored in the controller as a filter. The ANC controller “clears” the frequencies from the audio signal before it reaches the ear. The physical process behind ANC is called anti-sound. But, whilst the basic ANC concept remains the same, it can be implemented in several ways: feed-forward, feedback, or hybrid ANC.
5.Feed-forward ANC – the sensor microphone is on the outside
With feed-forward ANC, the microphone is placed on the outside of the ear piece. The microphone “hears” sounds before they reach the ear and transmits this information to the ANC controller. This then processes the noise and generates the anti-noise before the resulting signal is sent to the tweeter. This all happens in fractions of a second.
Advantages:
The microphone on the outside picks up noise early, so there’s more time to respond and create the “counter-noise”.
Disadvantages:
Feed-forward ANC has no way to correct itself since it does detect the sound signal output by the ANC controller. If the incidental noise comes from an unfavourable angle, it may inadvertently lead to amplification.
In addition, feed-forward ANC operates within a narrow frequency range. It has little effect on frequencies outwith this range. The microphone on the outside is also more sensitive to wind noise.
6.Feedback ANC – the sensor microphone is inside
With feedback ANC (analogous feedback information on the sound signal), the sensor is inside the earpiece and in front of the loudspeaker, so that the ANC controller can “hear” the resulting signal in exactly the same way as the listener.
Feedback ANC monitors the sound signal, which the ear also hears, and can therefore already respond to slight variations. Feedback ANC also works with a wider frequency range than feed-forward ANC. Another advantage is that feedback ANC can still reduce noise regardless of the angle to the sound source or if the ears are not completely covered.
For higher frequency transmissions, feedback ANC is not as effective as feed-forward. In rare cases it can actually exacerbate background buzzing noise produced since the sensor and tweeter are so close together. Feedback ANC can also filter out too much bass as noise.
7.Hybrid-ANC – Inner and outer microphones
As you may expect, a hybrid approach offers the best of both worlds and combines feed-forward and feedback ANC by placing a microphone both on the inside and outside of the earpiece.
The advantages of both ANC concepts are combined in the hybrid form. Hybrid ANC can suppress noise over a wider frequency range, adapt to and correct errors and is less sensitive to sound angle and user wear.
Due to this combination, hybrid ANC is much more complicated to implement and also more expensive to manufacture due to the number of high quality compents (microphones) that are necessary to create this system.
Nayin ENC TWS: NT13A/NT21A
Nayin FF ANC TWS: NT12A/NT18A
Nayin Hybrid ANC TWS: NT31A