Comparison among Passive Noise Cancellation, Active Noise Cancellation, Total Cancellation
July 22, 2019
▶ Passive noise cancellation is what the headset itself offers, whether rubber tips in an in-ear design or padding in an over-the-ear design. Very simply, it’s the amountof noise cancellation offered by the physical device, or how well the headset works as an earplug. While a good design will provide strong passive cancellation beforeelectronics are applied, passive cancellation is often limited to cancelling frequencies above 1 kHz. Even the best active electronics can’t compensate for poor acoustic design with minimal passive cancellation.
▶ Active noise cancellation (ANC) is the process of using a microphone to monitor environmental noise and creating anti-noise that’s then mixed in with audio playback to cancel noise entering the user’s ear. Active noise cancellation can be achieved with analog filters or digital filters, and is generally differentiated by architecture:feed-forward cancellation, feedback cancellation or hybrid cancellation. As mentioned, great active cancellation will significantly improve a headset with good passive cancellation, but can’t make up for poor design.
▶ Total cancellation—the noise-cancelling effect heard by the end user—is simply a measure of passive cancellation plus active cancellation. The ability of the active electronicsand the acoustic design acting together will determine the total cancellation that defines the quality of noise cancellation experienced by the user.