Best answer by Airgetlam
You can take an analog audio output from the TV and connect it to a line in on the Play:5, and use it that way. There will be, depending on the line-in settings, at least a 70ms delay between the video and the sound, and potentially more. Not an excellent experience, all told.
Sonos does make devices designed to be connected to TVs, called the PLAYBAR, PLAYBASE, and Beam.