Federal Court Breaks Silence: Declares Sonos did not Infringe Google's Noise Cancelling Technology Patent

Katie Graham is an IPilogue Writer and a 2L JD Candidate at Osgoode Hall Law School.

Sonos achieved a major milestone in their Canadian patent battle against Google, which follows several rulings in favour of Sonos in their corresponding US litigation (previously published in the IPilogue here).

In an infringement action against Google LLC (“Google”) dated August 15, 2022, Justice Zinn of the Federal Court of Canada ruled in favour of the defendants, Sonos, Inc. (“Sonos”). This case concerns the infringement of Claim 7 of Canadian Patent No. 2,545,150 (“150 Patent”) relating to Google’s method and apparatus for adaptive echo and noise control. Sonos counterclaimed, alleging that Claim 7 of the 150 Patent is invalid for obviousness and lack of invention.

The Court held:

  1. Sonos does not directly infringe Claim 7 of the 150 Patent;
  2. Sonos does not indirectly infringe Claim 7 of the 150 Patent by inducing users to infringe; and
  3. Claim 7 of the 150 Patent is valid.

This decision follows the dismissal of Sonos’ motion for summary judgment in March 2021, where Sonos alleged that Google made factual admissions in a corresponding US proceeding related to the infringement of US Patent No. 7,065,206, for which the 150 Patent claims priority. Justice Southcott of the Federal Court of Canada rejected Sonos’ arguments that Google’s voluntary dismissal in the US action represented an admission of non-infringement or eliminated any genuine issue for trial.


Claim 7 of the 150 Patent, owned by Google, details a method and device for echo and noise control in a device that adaptively determines an order of noise suppression and echo cancellation based on noise in the input signal. This patent allows for voice assistants in smart speakers, such as Amazon Alexa and Google Assistant, to change how much background noise is filtered out (i.e., noise suppression) when addressing a user’s commands, also referred to as “echos” (i.e., echo cancellation). Google claimed that five of Sonos’ products (collectively, “Sonos Devices”), all of which are compatible with Amazon Alexa and Google Assistant, infringed Claim 7 of the 150 Patent.


In constructing Claim 7, Google and Sonos’ experts disagreed on whether echo cancellation is a subset of noise suppression or whether these terms are mutually exclusive. Google submitted that “noise”, as confined to the asserted claim, was to be interpreted generally to include all background sound and user commands. In contrast, Sonos interpreted “noise” more narrowly to include only background sound, not user commands. Justice Zinn sided with Sonos to interpret noise in the narrow sense, thus concluding that echo cancellation and noise suppression are mutually exclusive processes.


Direct Infringement: Justice Zinn succinctly shut down Google’s claim that the Sonos devices directly infringe the 150 Patent. Out of the box, the Sonos devices are simply speakers and do not have voice assistants set up and configured. The essential elements of Claim 7, echo cancellation or noise suppression, require user activation of the compatible voice assistants. Thus, the court held that Sonos does not directly infringe Claim 7 of the 150 Patent.

Indirect Infringement: The Court focussed on considering whether Sonos indirectly infringed Claim 7 of the 150 Patent by inducing their users to enable Amazon Alexa or Google Assistant.  Justice Zinn sided with Sonos in finding that their technologies are not configured to adaptively adjust these elements based on input noise as described in Claim 7 of the 150 Patent. Instead, these processes are user controlled or done in a pre-determined manner. Consequently, the court held that Sonos did not indirectly infringe Claim 7 of the 150 Patent.


Justice Zinn used the approach outlined in Apotex Inc v Sanofi-Synthelabo Canada Inc, 2008 SCC 61 to assess the obviousness of the patent. Google and Sonos generally agreed on the person skilled in the art, common general knowledge, and the inventive concept of the claim. Sonos relied heavily on US Patent No. 5,668,871 (“871 Patent”) as prior art to assert that it would have been obvious for a skilled person to make the claimed invention in the 150 Patent. The Court rejected this argument, accepting Google’s submission that the skilled person would not easily come up with the 871 Patent and, therefore, the 150 Patent is not invalid for obviousness.


Google has yet to appeal this decision. A few days prior to the decision, Google announced two new US lawsuits against Sonos regarding voice control technologies.

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