The record first. On August 16, 2022, Synaptics Incorporated was granted US11418878B1, "Secondary path identification for active noise cancelling systems and methods" (CPC H04R 3/02 and H04R 1/1016). Named inventors include Wensen Liu and Govind Kannan. The method identifies the secondary acoustic path — the route from the cancelling speaker back to the error mic — which must be characterized for ANC to work robustly.

Follow the merchant-silicon model. Most consumer-audio brands buy their ANC capability as a chip-plus-firmware bundle from a merchant supplier rather than developing it. That model only works if the supplier owns the hard algorithmic IP — path identification, adaptation, stability — and ships it as a turnkey block. A secondary-path grant is the supplier fencing exactly that turnkey value.

“An active noise cancellation system has a secondary path including a loudspeaker configured to output an anti-noise signal to cancel noise in a noise cancellation zone, and an error microphone configured to sense sound in the noise cancellation zone.”— U.S. Patent No. 11,418,878 source

The business framing is who captures the ANC margin. When a no-name earbud advertises "active noise cancelling," the capability and its margin often sit with the silicon supplier, not the brand. Owning the calibration IP lets the supplier sell a higher-value block and resist being commoditized into a bare DSP. That stickiness is the revenue-durability story.

Comparability discipline applies. "ANC" spans the brands that build their own (a few) and the many that license it. The filing pins this claim to a foundational calibration step that turnkey suppliers must own — useful for distinguishing the suppliers that enable ANC at scale from the brands that merely badge it.

What the document does not disclose is the economics. It is a method claim, not a content figure. It will not tell you design wins, ASPs, or share. The grant establishes a turnkey-enabling position; the revenue is undisclosed.

For investors, the throughline is this: most consumer ANC is merchant silicon wearing a brand, and the patent record shows which suppliers own the turnkey capability the brands rely on.