https://techcrunch.com/2020/10/20/apple-homepod-update-brings-intercom-and-other-new-features/

Apple HomePod owners, starting today, will be able to use the newly announced “Intercom” feature to send messages between their HomePod smart speakers. The feature, which arrives via a software update, brings this and several other new features to Apple’s smart speakers, including those introduced at Apple’s event last week where the company debuted its $99 HomePod mini.

Of these, Intercom is the most notable update, as it helps the HomePod catch up to rival smart speakers, like those from Apple and Google, which have offered similar broadcast messaging systems for years.