Federal Circuit Revives Sonos’s $32.5M Verdict Against Google, But Affirms Invalidity of a Third Patent
The CAFC looks at alleged "new matter" in a continuation
In a significant, though non-precedential, decision, the U.S. Court of Appeals for the Federal Circuit has altered the outcome of the high-profile patent dispute between Google and Sonos. On August 28, 2025, the court reversed a district court judgment that had invalidated two of Sonos’s patents related to multi-room speaker control. This reversal reinstates a jury verdict of over $32.5 million for Sonos. However, the panel affirmed the invalidity of a third Sonos patent concerning remote media playback.
The case, Google LLC v. Sonos, Inc., (2024-1097) involved three patents generally directed to controlling media playback systems. The decision provides important insights for patent practitioners on the doctrines of written description and prosecution laches.
The "Zone Scene" Patents: Written Description and Laches Holdings Reversed
The core of the dispute revolved around Sonos’s U.S. Patents 10,469,966 and 10,848,885, dubbed the "Zone Scene patents." These patents cover the creation of predefined groups of speakers, or "zone players," that can play audio in sync. The key feature at issue was the claiming of "overlapping" zone scenes, where a single speaker could simultaneously belong to two different predefined groups.
The district court’s handling of these patents was unusual (p. 12). After initially granting summary judgment of infringement to Sonos, the court reconsidered its position post-trial. The Federal Circuit first addressed a procedural irregularity, noting the district court had framed its invalidity decision under 35 U.S.C. § 102, using the theory that Google's infringing products anticipated the claims once the priority date was moved to 2019 because an amendment to the patent specification constituted new matter that was not supported by the original 2007 priority application (p. 10).
The panel corrected this approach, explaining that because the patents at issue were continuations—not continuations-in-part—the proper legal analysis for the alleged new matter is the written description requirement of § 112. For clarity, the court announced it would treat the district court's judgment as one arising under § 112, even while acknowledging this might be a "distinction without a difference" (p. 10).
On the issue of written description, the Federal Circuit found dispositive support for the "overlapping" feature in the original 2007 nonprovisional application (US 8,483,853). The court pointed to a section describing a "Morning Scene" and an "Evening Scene," both of which included the "Bedroom, Den and Dining Room" zones (p. 13).
This disclosure, the court stated, "plainly provides adequate written description for overlapping zone scenes, where each of the Bedroom, Den, and Dining Room simultaneously belong to two different zone scenes" (p. 13).
The court dismissed Google's argument that these were "alternative embodiments," concluding that "[n]o reasonable factfinder could conclude that that language... is directed to an entirely separate and 'alternative' embodiment" (p. 14)
The lower court also found the patents unenforceable under the doctrine of prosecution laches. It held that Sonos "was guilty of unreasonable and inexcusable delay" by waiting thirteen years, from a 2006 provisional filing until 2019, to claim the overlapping zone scene feature (p. 8). The court determined Google suffered prejudice because it "began investing in the accused products by at least 2015, when it released its first products that practiced the invention" (p. 8). The Federal Circuit reversed both of these holdings.
On prosecution laches, the Federal Circuit found that Google failed to establish it had suffered prejudice from any delay by Sonos. The court noted that Google "presented no evidence—testimony or otherwise—to support its assertion that its investment in those products actually began in 2015" (p. 16).
More critically, the court explained that the 2007 application, which it had already found contained adequate disclosure, was published as a patent in July 2013 (p. 16), before Google’s alleged investments began.
Therefore, "Google cannot be prejudiced by incorporating into its products a feature that was publicly disclosed in a patent application prior to its investment" (p. 16). The unenforceability holding was consequently overturned.
The "Direct Control" Patent: Obviousness Finding Affirmed
The outcome was different for Sonos’s U.S. Patent 10,779,033, the "Direct Control patent." This patent is directed to using a device like a smartphone to transfer playback responsibility of a "remote playback queue" to a speaker.
The district court had granted summary judgment to Google, finding the asserted claims would have been obvious over Google's own prior art: a version of "YouTube Remote" (YTR2) in view of a Google patent on the same technology (U.S. Patent 9,490,998).
The Federal Circuit agreed, finding "no genuine dispute of material fact" that the combination rendered the claims obvious (p. 17). For the "remote playback queue" limitation, the court found that YTR2 met the claim requirement of being "configured for playback of a remote playback queue provided by a cloud-based computing system" (p. 18).
For the "device picker" limitation, the court found the '998 patent disclosed the ability for a user to "select one of more previously paired controlled devices," which taught the claimed feature (p. 18). The invalidity judgment for the Direct Control patent was therefore affirmed.
Analysis
For Sonos and other patent holders, this decision reaffirms the power of a well-drafted priority application. The detailed disclosure from 2007 was instrumental in defeating both the written description and prosecution laches challenges, thereby reviving a substantial damages award. The ruling clarifies that the prejudice element of laches is difficult to prove when the core invention was publicly disclosed—even if not yet explicitly claimed—before the accused infringer’s investment. While not precedential, the cited cases provide a helpful guide for articulating similar rationale.
On the other hand, the decision highlights the difficulty for accused infringers in asserting prosecution laches. A defendant must provide concrete evidence of prejudice tied to the patentee's delay in claiming, not just delay in filing. The public disclosure of the technology in an earlier patent or application can neutralize the argument that the defendant was "caught unawares" by the later-filed claims (p. 16).
For patent practitioners, this case serves as a valuable reminder of both prosecution and litigation strategy. The survival of the Zone Scene patents depended entirely on the quality of a specification written over a decade earlier.
For litigators, Google’s procedural choice to raise its written description argument only in opposition to Sonos's summary judgment motion, rather than in its own affirmative motion, created an "unusual posture" that complicated the case (p. 11). While the Federal Circuit ultimately addressed the merits, this path introduced procedural risk—all or nothing.
Looking Ahead
The Federal Circuit's decision breathes new life into Sonos's infringement case concerning its core Zone Scene technology. The court has reversed the judgment of invalidity and unenforceability for the '966 and '885 patents and affirmed the invalidity of the '033 patent. The case now returns to the district court, which is "instructed to consider, in the first instance and if still contested, any remaining motions mooted by its judgment." (p. 19).
As a non-precedential opinion, the decision is not binding, but its reasoning offers persuasive guidance on written description requirements where “new matter” may be added and applying the doctrine of prosecution laches.
Disclaimer: This is provided for informational purposes only and does not constitute legal or financial advice. To the extent there are any opinions in this article, they are the author’s alone and do not represent the beliefs of his firm or clients. The strategies expressed are purely speculation based on publicly available information. The information expressed is subject to change at any time and should be checked for completeness, accuracy and current applicability. For advice, consult a suitably licensed attorney and/or patent professional.