Unfortunately a Sonos Beam SL doesn’t exist. But there is a Sonos Arc SL Shadow Edition available as a Costco exclusive:

https://www.costco.com/sonos-arc-sl-shadow-edition.product.100696167.html

I'd hate to ask: what security reasons?

The microphone on the Beam can be turned off and on using the touch control on tbe Beam

I wanted a Beam without a mike too, don’t need some outside computer listening to me.

Talking with the Sonos folks convinced me that just having the mike option was very low risk as it required several steps to allow it to be activated.

Still would have rather not had it.

When Sonos launched their first voice activated speaker they made a point of saying that the microphone was hard wired to the microphone LED, and that there was no software means to enable or disable the mic.  Therefore if the LED was off the microphone had to be off.  To the best of my knowledge that remains the case for all such speakers.

I am sure there will be some who trust that assurance reluctantly or not at all, but that is a matter of personal choice.

Don’t install a voice assistant, and the mic LED will never illuminate. 

Do you have a cellphone? That has a microphone in it.

Yes I do have a cell phone and I don’t keep it where it can overhear my conversations.

Ticks a lot of folks off because I also refuse to run to answer it even if I hear it ring. If they can’t do a text or leave a voice mail we aren’t likely to even know they called.

Don’t like the mikes in several other devices and since I don’t use them they are plugged.

Only devices mikes I actually use are in my FireStick, love it and it works well, but ONLY when I hold down the mike button the other is in my hearing aids, again a solid button push is needed to activate.

I’d be tempted to try the Sonos mike if it could be used the same way. Sadly there is far too much chance of bumping the aggravating touch controls.