TOPIC: Weird Combine Sounds - Help please

I installed some Addons recently and uninstalled them 2 Days ago. Now I get a weird Combine Sound or something playing in the Background (Stopsound is not working) The Sound loops until you close the Game. I have 2 Soundpacks installed but never got a Problem with that ( I downloaded them 2 years ago)
1. steamcommunity.com/sharedfiles/filedetails/?id=154509410
2. steamcommunity.com/sharedfiles/filedetails/?id=505516709

Here is a Video of the Sound:
You need to make the Video a bit louder so you can hear it clearly.
The Sounds starts randomly after 10-60 Minutes and loops until I close Garry's Mod
I had the same problem 4-5 Month ago but somehow I fixed it.

I hope someone can help me. Thanks!

Own fault , stop watching Star Trek... could help

Have you checked your sound files?

Sure you didn't install something that adds ambient sounds?