The record first. On June 21, 2022 — filed earlier, in the 2021 cohort — Cirrus Logic, Inc. was granted US11367426B2, "Communication apparatus with ambient noise reduction" (CPC including G10K 11/1783 and H04R 1/1083). The named inventor is Alastair Sibbald. The claim covers noise-reduction circuitry and method — the audio-processing function that consumers experience as call clarity and ANC.

Follow the content per socket. Audio-silicon suppliers, especially those concentrated on a few large customers, grow by selling more capability per device — moving from a basic codec to a smart amplifier to integrated noise reduction. Each step raises the dollar content and the switching cost. A noise-reduction grant is a marker of the supplier climbing that ladder inside the same handset and earbud.

“A host device configured to be wirelessly coupled to an accessory device, the host device comprising noise reduction circuitry, wherein, in use of the host device: a signal generated by a microphone of the accessory device in response to ambient noise is supplied to the noise reduction circuitry; th…”— U.S. Patent No. 11,367,426 source

The business framing is concentration risk and content. A supplier heavily reliant on one OEM defends itself by becoming indispensable — owning audio functions that are expensive to redesign and patent-fenced against substitution. The ambient-noise-reduction IP is exactly that kind of stickiness, which matters to anyone modeling the supplier's revenue durability.

Comparability discipline applies. "Audio silicon" spans codecs, amplifiers, haptics, and noise processing; they are distinct content lines. The filing pins this claim to ambient noise reduction — useful when assessing which functions a supplier owns versus competes for, and easy to blur under the catch-all "audio chip."

What the document does not disclose is the economics. It is a method-and-apparatus claim, not a content figure. It will not tell you dollar content per device, customer concentration, or margin. The grant establishes a defensible function; the revenue it earns is undisclosed.

For investors, the throughline is this: audio-silicon suppliers grow by deepening content per socket and fencing it in IP. A noise-reduction grant is a concrete marker of that deepening.