Google fires back at Sonos with its own lawsuit after the smart speaker company sued it over alleged patent infringement

• Google has countersued Sonos over alleged patent infringement, escalating a legal battle between the two companies, as first reported by The Verge and confirmed to Business Insider.
• "We are reluctantly defending ourselves by asserting our patent rights," a Google spokesperson told Business Insider, saying Sonos had made "false claims" about Google's technology and its work with the tech giant.
• Sonos originally sued Google in January, accusing it of "blatantly and knowingly copying our patented technology."
• Sonos' CEO also testified against Google during a congressional antitrust hearing this year, accusing the company of various anticompetitive behaviors.

Google filed a patent infringement lawsuit against smart speaker maker Sonos on Thursday, as first reported by The Verge and confirmed to Business Insider, escalating an ongoing legal dispute between the companies.

"We are disappointed that Sonos has made false claims about our work together and technology. We are reluctantly defending ourselves by asserting our patent rights," Google spokesperson Jose Castaneda told Business Insider in a statement.

In the complaint, Google accused Sonos of using "substantial volumes" of its technology, including "patented Google innovations in search, software, networking, audio processing, and digital media management and streaming," without its permission.

Google also stressed its partnership with Sonos in the complaint, saying it had "worked constructively with Sonos to make the companies' products work seamlessly by building special integrations."

The lawsuit comes in response to Sonos' own patent suit against Google, filed in January, which accused the tech giant of "blatantly and knowingly copying [Sonos'] patented technology in creating its audio products."

Sonos, which makes home speakers that work with both Google's artificial-intelligence-powered Assistant and Amazon's Alexa, had said that as it pressured Google to officially license its technology, Google asked Sonos to adhere to unreasonably strict terms, such as alerting Google to names and designs of future products six months in advance.

Later that month, CEO Patrick Spence criticized Google during a congressional hearing on antitrust for what he said were anticompetitive behaviors.

The advantages Google has in marketing its own products "are like nothing we've ever seen before," Spence said. He alleged that Google had pressured Sonos to only allow its speakers to sync up with Google Assistant, rather than also offering it on Amazon's competing voice assistant Alexa.

Google is currently facing a number of antitrust lawsuits at the state, federal, and international levels, and Reuters reported that the US International Trade Commission opened a patent probe into some of Google's audio products following Sonos' lawsuit.

"Instead of simply addressing the merits of our case, and paying us what we're owed, Google has chosen to use their size and breadth to try and find areas in which they can retaliate," said Sonos CEO Patrick Spence in a statement to Business Insider.

"As we saw in the past with Eero, and have seen most recently with Zoom, Google seems to have no shame in copying the innovations of smaller American companies in their attempts to extend their search and advertising monopolies into new categories.

"We're mostly sad to see a once innovative company with the mission of 'Do No Evil' avoid addressing the fact they've infringed on our inventions, and have turned to strong-arm tactics the robber barons of old would have applauded."

Avery Hartmans and Bani Sapra contributed reporting to this story.