No one can hear me - can't find any solution

For one member of our clan, TeamSpeak is picking up his voice, his mic works, we can even see the light flickering when he talks on TS, but no one can actually hear him. We tried setting both push-to-talk and voice activation, he is granted all rights to talk on the server, but not even the internet knows what to do, we searched so many posts. For an hour, it started working just like that, no idea why, out of nowhere and then stopped working again. Also tried to change to input device, nothing. He could hear us the whole time, but we couldn’t hear him. Anyone please, we’re getting pretty desperate?

are you sure that the microphone works properly? You can try to hear yourself in the settings
-> Extras -> Settings -> Recording -> “Start Test”

#Solution 2
Try the speaking method in Windows
-> Sounds -> Recording -> Choose your Microphone -> Listening -> on the second label check it