I don’t think there is. The zoom app includes a microphone so that you can talk as well as listen, and that’s why it can’t cast the audio to your TV, since the atavistic doesn’t have a mic. The only people so far who have used the published integration with the a Sonos mics are Google and Amazon. You’d need to ask Zoom to do that integration as well, before it would become possible, and given the issues with security that their platform currently is experiencing, I would not expect it to be soon. But you could certainly point them to the Sonos partners page, and ask them to be part of Sonos.

The smartcast should have audio too

from some posts on Samsung forum:

Samsung fixed this issue for me.

All you need to do is turn off your tv, unplug it from the wall, wait 3 - 5 mins, plug it back in and turn on your tv. A reset of sorts. You should be able to have audio when you screen mirror now.-

Ok everyone I think I got it figured out. Go to your normal SETTINGS on device. Then go to SOUND settings. Click on the VOLUME tab. While you have your device connected to your TV using smart view turn up the MEDIA bar all or close to all the way. That fixed it for me after months of trying to figure it out and giving up multiple times Haha. Hope this works for everyone else. Feel stupid for how simple it ended up being.

Go to the
settings
Smart view
Force stop.
Good luck 

If you're using a Samsung Smart TV what setting do you have the audio on the Samsung TV I'm using has 3 audio settings standard optimized and amplify I switched to optimize and the audio is working for me now

Hi I have noticed that if you have an external audio device connected such as a sound bar it won't play through it simply disconnect the device and it works. Not sure if this would help you. Haven't figured out how to play through sound bar yet

Edit:

Ok so some apps on smart view can only be heard through the bar if PCM mode is enabled instead of digital dobly

Once I corrected the Media volume on the phone as suggested, my wsound worked on the sound bar through the TV connection.  It should not be necessary to connect the phone to the sound bar.

Interesting question.  I also have Samsung TV, phone, and playbar so I thought I’d see if I can figure out a solution to your problem.  Starting with Zoom, I don’t think there’s anything done here.  I’ve only started using Zoom, but I am pretty sure it doesn’t have any casting features.  On to Smart View, it looks like it has the ability to cast video (no audio) to the TV, or sound to a speaker, but not both at the same time.  So yes, it looks we won’t get a solution there.  The Sonos app isn’t going to help you really either, since you can only played stored media from you phone, or audio coming from your TV.  So I don’t really think you’re going to get audio on the TV.

However, I think bluetooth audio can help for this.  Connect your video to the TV like you’re doing, and then send the audio to bluetooth headphones or speaker (a Sonos Move works, but any bluetooth speaker).  I tried both options myself and the video on the TV and audio matched up pretty well.  

Really, this is something Samsung needs to fix with it’s smart view.  If audio went along with the video, than no issue.  I also wouldn’t be too surprised to see Zoom come out the a TV after fairly soon, as the current environment has increased it’s popularity.

EDIT: Forget what I said, Chris is correct  Smart View well send audio, you just need to make sure the volume is turned up.  It worked for me.  I didn’t have to change much on the settings or restart anything.  While smartview  is on, I pressed the volume up button on my phone.  That creates a volume slider bar at the top of the screen.  Press the down arrow button on the right side to see the different volume can control.  Media is what you’ll want to use to control the volume I think. 

So Danny … essentially your saying I’m smarter than you ?

….. but the TV is probably still smarter

This was already established fact.

edit:  And it’s “you’re”, not “your”.  

Thank you all so much!  Am doing another zoom class tomorrow (sucker for punishment) so will try and cast sound and report back.  

Nothing worked - I can cast picture fine, but sound will only come from mobile device.  Have spend hours looking at ways round this, but couldn’t get Zoom to mirror sound onto my Samsung KS8000 TV.  With Smartview enabled I can mirror sound from other apps  (played a Whatsapp gif fine) but couldn’t get Zoom audio to come out of the playbar.  I have a Samsung Galaxy S3 tablet and a Samsung Galaxy S8 phone and same result with both.   If anybody has a magic solution I’d be very grateful but it’s not the end of the world really :)

i know its a cheat but until its all easy just get an hdmi cable and plug it into ur tv (ok i know phones and mobile devices do not have an hdmi port but we are all at home so like me ur lap top/pc usually has one. And amazon still deliver hdmi cables.

Exactly same issue with HDMI, only picture on the TV but no sound through Sonos Playbar. Youtube is fine as Sonos must have integration with that.