Question about speakers (home theater speakers)

[Hellis81]

I’m trying to solve my problem in this project.
TL/DR, I have two kids that is making noise, which the microphone picks up, which turns down the volume.

Turn down volume of TV/receiver when it's too loud

Every time we watch TV we have to basically hold the remote in the hand because the volume varies so much. I thought of an idea. Use a microphone to measure the sound coming out of the center speaker behind the TV and adjust the volume of my Yamaha receiver. See it in action (with a volume up again after 1 second). (high number means low volume on this receiver since it’s negative db scale) [Level sound] I added a gy-max4466 microphone on a breadboard with a ESP8266. Gave it 3.3…

So if I skip the microphone and connect the ESP to my receiver I get the true sound, not noise.

I connected the multimeter to the center speaker cables, I get DC 0 volt. AC pending around 0.1-0.2 volt.

Question, Is that safe to input on analog input?
As I see it I must be getting negative voltages since there is no carrier voltage for the signal (?).
If it had something on DC then it would be fine, right?
What can I do to get this signal in to the ESP? Will it work if I add a diod bridge/bridge rectifier making it DC? In my simple mind that should remove the negative part of the signal and just give me a varying DC voltage(?).

Anyone have knowledge of this?