Hej everyone!
I'm quite new to Sweden so please forgive my use of English instead!
I've recently bought an apartment in an old building in central Stockholm. Unfortunately, the bedroom has serious issues with noise coming through the wall from the neighbour (it is literally as if they are talking in the same room). I've therefore been in contact with a soundproofing company and the solution is to build a new (soundproofed) wall in front of the existing one.
A potential issue is that, in the top left of this wall, there is an existing ventilation hole. I'm not sure whether it's specifically used for ventilation, or whether it's the old hole left from where an eldstad / stove used to be. Regardless of this, in order to soundproof properly, this hole would need to be covered up.
Are there / could there be any issues with doing this? I have ventilation exit points elsewhere in the apartment, including: (i) the adjacent living room, (ii) the toilet, (iii) the bathroom and (iv) the kitchen.
Thank you!