Active Noise Cancellation: FF v/s FB

ANC stands for Active Noise Cancelling. It is a technology that helps to reduce unwanted ambient noise by generating sound waves that are the exact opposite of the noise. These sound waves, also known as anti-noise or destructive interference, cancel out the noise, making it less audible or even inaudible.

There are two main types of ANC:

1. Feedforward (FF) ANC: FF (Feedforward) ANC is the most common type of ANC used in consumer headphones. In this type of ANC, a microphone located outside the earpiece or speaker captures the ambient noise and sends it to a digital signal processor (DSP). The DSP then creates an opposite sound wave (anti-noise) that cancels out the ambient noise before it reaches the listener's ears.
2. Feedback (FB) ANC: This type of ANC uses a microphone inside the earpiece or speaker to pick up the sound waves produced by the driver or speaker. The DSP analyzes the sound wave and generates a correction signal that cancels out the unwanted noise.

Both FF and FB ANC have their advantages and disadvantages.

FF ANC is generally more effective at canceling out low-frequency noise, while FB ANC is better at canceling out higher-frequency noise. FF ANC also tends to produce less distortion, while FB ANC can produce a "boomy" or "hollow" sound in certain situations. Many Earbuds/headphones also use a hybrid approach that combines both FF and FB ANC for optimal noise cancellation performance.