Speakers for announcements

Hello Everyone. I'm looking for some advice on speakers for a shop environment. We have a rather large manufacturing facility that has TV's throughout the shop that display Info about various things. We have recently started a scheduled alert that will pop-up on the screens at the same time everyday to prompt people to clean their areas. Unfortunately the flat screen TV's that we use don't have enough volume to overcome the ambient noise level in the shop for this alert.

We are wanting to add an external speaker to each TV to help with this and I was looking for some recommendations. We don't want to use bluetooth because there are often stability issues, and we don't want to have all of these speakers wired back to a central amplifier. We don't need stereo sound or a subwoofer. We won't be watching movies/tv on any of these screens. It will only play the alert noise.

Ideally we would use a wall mountable self-powered speaker with a 3.5mm aux input and just connect it to each screen. I've looked on Amazon and while there seems to be a number of options the reviews on a lot of them seem to be mixed bag. Does anyone have any suggestions?