(Pocket-lint) - Sonos has filed to become a public company, seeking to raise up to $100 million in the process. But part of its filing to the US Securities and Exchange Commission reveals an alarming fact about its Sonos One and Sonos Beam speakers. In particular, their Alexa voice assistant support.

The company claims that the deal it has with Amazon enables the owner of Alexa to withdraw integration with "limited notice". That would remove voice interaction as things stand, until Sonos can strike deals with other assistant technology firms: "Our current agreement with Amazon allows Amazon to disable the Alexa integration in our Sonos One and Sonos Beam products with limited notice," a clause in the filing reads.

"As such, it is possible that Amazon, which sells products that compete with ours, may on limited notice disable the integration, which would cause our Sonos One or Sonos Beam products to lose their voice-enabled functionality."

Alternatively, Amazon could chose to charge Sonos to use Alexa in its products, cutting into Sonos' profits and potentially raising the prices of its speakers: "Amazon could also begin charging us for this integration which would harm our operating results."

Sonos has always been open about working with other partners. Google Assistant support, for example, has been promised since the launch of the Sonos One in 2017. Adding that support alongside Alexa would soften the blow should one or the other become unavailable for whatever reason. There is no guarantee that a deal with Google can be struck, however: "We are working to establish partnerships with other companies that have developed voice-control enablement technology, but we cannot assure you that we will be successful in doing so," the filing continues.

"If Amazon does not maintain the Alexa integration, if Amazon seeks to charge us for this integration, if we have not developed alternative partnerships for similar voice-enabled products or if we have not developed such products on our own, our sales may decline, our reputation may be harmed and our business and operating results may suffer."

Whether this ever happens is another story. It might just be standard practice for Amazon to include these stipulations in its deals with third-party partners and purely added as a safeguard. We've certainly not heard of a partner having integration removed in the past.

We have reached out to Amazon for comment to find out.

We also asked Sonos to comment but, understandably, it has to be careful what it can say during an IPO filing period: "As you can appreciate, we’re in a quiet period and can’t discuss details publicly," it told Pocket-lint.

Writing by Rik Henderson.