If it has a speaker, then it has a mike.
https://duckduckgo.com/?q=using+speaker+for+microphone&ia=web
Sure, a speaker can serve as a microphone, but only if the electronics is made to use it that way. Such is not the case for my TV. Not only that, is not capable of sending data upstream either. It must be used with a media source since it does not contain one. (It is not a recent model.)