Maybe have a polite conversation with the neighbor first to see what the issues are. You can explain that it seems they react to light sounds at times and you want to work together to find an acceptable level. Then you can both experiment so see what things sound like standing in both apartments.
If they don’t want to do anything like that then tell the landlord to get involved.
It seems weird that someone would go through the trouble of putting a microphone in place to eavesdrop on your whispered conversations only to bang on the wall in objection to unfriendly comments. That kind of defeats the purpose of being sneaky and nosy, doesn’t it? Either that or maybe your test commentary actually isn’t all that quiet.
Maybe have a polite conversation with the neighbor first to see what the issues are. You can explain that it seems they react to light sounds at times and you want to work together to find an acceptable level. Then you can both experiment so see what things sound like standing in both apartments.
If they don’t want to do anything like that then tell the landlord to get involved.
It seems weird that someone would go through the trouble of putting a microphone in place to eavesdrop on your whispered conversations only to bang on the wall in objection to unfriendly comments. That kind of defeats the purpose of being sneaky and nosy, doesn’t it? Either that or maybe your test commentary actually isn’t all that quiet.