As far as i could research it is technically feasible though very impractical and low quality, way easier to sell people voice command features instead.

As i understand it also depends on whether its a “active” speaker or not, has an amplifier behind it.

Tvs usually use a speaker array, a bad actor company could design it in a way that one or two of those can be used to record sound in case the microphone is no longer detected.

An ad collector wouldn’t go that far on purpose, a state intelligence operator who is covertly part of the company might.