Controlled residential ventilation - You can hear every word in the other room - Is this normal?

We also hear a noise, sometimes louder, sometimes quieter. But we do not hear any voices from the tubes. Also drywall above. What kind of floors do you have? Who installed them?

I only hear a slight rustling when I am about 50cm close to the [Zuluftöffnung]. When I just stand underneath, I hear nothing.

Best regards
Sabine

Upstairs you can also hear voices but you cannot understand everything. On the ground floor, you can hear EVERYTHING said in the "Allraum" clearly in the guest bathroom. Luckily, my father pointed out to us that he continued to listen to the entire conversation.

Floor coverings:
Ground floor completely tiled, all the same tile. Upper floor all vinyl flooring. Installed by the tiler and floor installer of the general contractor. Was not self-performed.

Could it be that you didn’t lay the tiles below with a decoupling layer? Some kind of connection to the walls? So that it transmits?

No, I had seen this tape before the screed installation. The noise really goes through the pipes. It also sounds like a tin can telephone. Especially bad on the ground floor. You can really hear that it comes from the exhaust air. My father thought that was just how it is in new houses... And just wanted to warn us...

Sounds like a tin can telephone.

In my childhood we had that too: an empty conduit ended behind a living room cabinet, and every word could be heard clearly in the attic. What could possibly absorb or "dent" the sound in such a pipe?