Federal Circuit Decision
On June 9, in Google LLC v. Sonos, Inc., the Federal Circuit reversed and remanded the decision by Patent Trial and Appeal Board (PTAB) that had found numerous claims of Google’s US Patent Nos. 10,134,398 and 10,593,330 were unpatentable, finding that the PTAB’s anticipation analysis was not supported by substantial evidence and failed to support key claim limitations directed to multi-device coordination and suppression of unintended voice activation while remaining in low power mode.
Patent Background
Both the ‘398 and ‘330 patents relate to technology commonly used in voice-activated systems, where a “hotword” prompts a device to respond to user commands, and synchronizing the hotword detection across multiple sound-enabled devices such that only one device responds. The ruling has received interest because of the prevalence of hotword detection in numerous AI and assistant programs.
IPR Challenge and Key Dispute
Sonos, Inc. filed inter partes review (IPR) petitions challenging claims of the Google patents as anticipated by and obvious over prior art. The prior art discloses listening for the hotword in low power mode, which then acts as a trigger for one of the multiple devices to respond. The central dispute was whether the prior art disclosed devices exchanging messages while remaining in low power mode. Google argued that the prior art describes devices that detect the hotword, exit low power mode, then exchange messages to determine which device responds. Google’s patents are directed to exchanging weighted messages while remaining in low power mode.
PTAB’s Reasoning
The PTAB agreed with Sonos, stating that the prior art discloses a device which “normally operates in a low power listening mode[.]” The PTAB continued asserting that the device may also, “[u]pon receiving and recognizing a speech trigger phrase and determining that it is in a better position to handle subsequent user interaction than any other device[,]” or when “instructed to wake up[,]” will beep and change its status light. The PTAB likened this to the weighted low power messaging system Google describes, and indicated that the signal is ‘weighted’ by which device is in the best position to answer. The PTAB, based on expert testimony, concluded that this disclosure encompassed exchanging signals while remaining in low power mode. Google appealed to the Federal Circuit.
Federal Circuit’s Analysis
The Federal Circuit reversed the PTAB’s decision, finding that the PTAB had misread the relevant passages from the prior art. The Federal Circuit explained that the prior art’s failure to disclose the combination of features, as well as in what order the features occurred. The referenced prior art describes embodiments in which devices exit the low power mode before performing coordination. The Federal Circuit determined that the PTAB misread the prior art by insinuating that the mere existence of both features in the reference was enough and instead need to clearly demonstrate that the reference describes both features in use at the same time. This difference means that the prior art did not benefit from the increased energy-efficiency in messaging while remaining in low power mode. As such, the court found that the PTAB failed to adequately explain how the prior art disclosed the claim language. Because anticipation requires that a single reference disclose every claim limitation, the absence of this limitation was dispositive.
Implications for Patent Drafting and AI Technologies
The court further declined to affirm on Sonos’s alternative theory that coordination occurs in a different “low power mode,” noting that the PTAB had made no factual findings on that issue and remanding for further consideration. The Federal Circuit’s decision underscores the rigorous substantial evidence standard applied to PTAB anticipation findings and the importance of precise claim limitations tied to operating modes. The decision may have implications for future patent disputes involving AI and interconnected devices. As the prevalence of AI and assistant programs grow, ‘always on’ infrastructure may be impacted by the ruling. Many other AI and assistant programs also utilize hotword activation. These programs rely on coordination and interaction as core to their innovation. As patent claims remain attached to concrete technological solutions, the questions raised in this decision concerning coexistence of features, and timeline of use will be applicable to many other cases in the future as well. Patent drafters should be mindful to include details necessary to describe the invention logically from the ground up. Successful anticipation challenges will require an approach based strongly on the factual record.
For more information on this topic, please contact Fitch Even partner Steven M. Freeland, author of this alert.
Fitch Even summer associate Aidan O’Grady contributed to this alert.
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Steven M. Freeland
Steven M. Freeland practices in all areas of intellectual property law, focusing primarily on the development, protection, and management of intellectual property. Steve assists clients with sophisticated patent portfolio management and the prosecution of complex patents, helping them to manage their patent assets using strategies tailored to further their business objectives.