Sonos Inc v. Google LLC

1. Case Identification

• Case #: IPR2023-00118
• Patent #: 10,134,398
• Filed: October 27, 2022
• Petitioner(s): Sonos, Inc.
• Patent Owner(s): Google LLC
• Challenged Claims: 1-5, 7-13, and 15-20

2. Patent Overview

• Title: Hotword Detection on Multiple Devices
• Brief Description: The ’398 patent relates to systems and techniques for managing hotword detection across multiple computing devices. The technology addresses the problem where several nearby devices might detect a spoken hotword, ensuring that only the single, most appropriate device responds to the user.

3. Grounds for Unpatentability

Ground 1: Anticipation by Rosenberger - Claims 1-3, 7-8, 10-11, 15, and 17-18 are anticipated by Rosenberger.

• Prior Art Relied Upon: Rosenberger (Patent 8,340,975).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Rosenberger discloses every limitation of the challenged independent claims (1, 9, and 16). Rosenberger describes a system of multiple speech-recognizing "control devices" designed to solve the same "duplicate response" problem as the ’398 patent. Petitioner contended Rosenberger’s devices operate in a "low power ‘listening’ mode" to detect a "trigger phrase" (the claimed "hotword"). Upon detection, each device calculates a "numeric weighted signal" (WS) that quantifies the recognition quality (the claimed "output of processing"). The devices then transmit their WS values to other devices and receive WS values in return. Based on a comparison of these WS values, only the device with the highest score exits the low-power mode to interact with the user, while the others determine to remain in the low-power mode. This process, Petitioner asserted, directly maps to the claimed sequence of receiving audio, transmitting an output, receiving an additional output from another device, and determining to remain in a low power mode.
  • Key Aspects: The argument focused on the direct parallel between Rosenberger's coordination method using "weighted signals" and the ’398 patent's claimed method of using a "hotword confidence score" to arbitrate between multiple devices.

Ground 2: Obviousness over Rosenberger and Basye - Claims 4-5, 12-13, and 19-20 are obvious over Rosenberger in view of Basye.

• Prior Art Relied Upon: Rosenberger (Patent 8,340,975) and Basye (Application # 2014/0163978).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that while Rosenberger teaches the core multi-device arbitration system, Basye provides the specific teachings for the remaining dependent claims. Basye discloses power management techniques for voice-controlled devices. Specifically, Basye teaches determining a "score or confidence level" corresponding to the likelihood that a "keyword" (or "wakeword") is present in speech. Basye further teaches that if this score "satisfies a threshold," the device determines the keyword is present and may activate other modules. Petitioner asserted that combining Basye’s threshold-based confidence scoring with Rosenberger’s system would render claims 4, 12, and 19 obvious, which require determining a "hotword confidence score" and that it "satisfies a threshold." Petitioner also argued that Basye teaches performing this keyword detection without full speech recognition, which maps to the limitations of claims 5, 13, and 20.
  • Motivation to Combine: A POSITA would combine Rosenberger and Basye for several reasons. Both references are in the same field of voice-controllable computing devices. Rosenberger’s system, which can include battery-powered devices, would benefit from the improved power efficiency taught by Basye. A POSITA would be motivated to incorporate Basye's thresholding mechanism into Rosenberger’s system to reduce "false positive" detections of the trigger phrase. This would prevent the devices from unnecessarily broadcasting their weighted signals, thereby conserving power and processing resources, a known goal in the art.
  • Expectation of Success: A POSITA would have a reasonable expectation of success in combining these references. Implementing a known thresholding technique (from Basye) to qualify a trigger event before initiating a network communication (in Rosenberger) was a straightforward application of known design principles to achieve the predictable result of improved system efficiency and reliability.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §314(a) based on Fintiv factors would be inappropriate. It was asserted that the parallel district court action was stayed pending a related ITC proceeding, resulting in minimal investment by the court and parties and no risk of duplicative efforts or inconsistent rulings.
• Petitioner also contended that denial under 35 U.S.C. §325(d) would be inappropriate because the USPTO examiner materially erred during prosecution by failing to consider Rosenberger and Basye. Petitioner further noted that its arguments were supported by a new expert declaration, which was evidence not previously available to the examiner.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-5, 7-13, and 15-20 of the ’398 patent as unpatentable.