Sound problem: Does noise come through masonry - through the exterior plaster?

I was merely concerned here with the small joints between the stones. About 2-5mm in size. The head joints.[...] what is better: to leave them completely open and hope that the plaster solves the problem

Hello,

we built in a small suburb of Ulm, near a smaller street (about 6000 vehicles per day). The street is about 20-30m away, and on both sides of us, there is still a building gap.

Poroton bricks are used as masonry.

Anyway, we were assured during the sale that noise would definitely only be an issue through windows, which is why we chose special roller shutter boxes and partly soundproof windows.

Currently, we still have scaffolding on the house that is connected to the house and the ground. The exterior plaster is not yet applied and will follow later. What unsettles us is that we always hear the street, and depending on the wind and weather, even more clearly, on every floor and basically in all rooms, even where there are soundproof windows (class 3). It is as if a window is permanently tilted open. When we put our ear along the wall, we can clearly hear the noise coming through the wall. It is much quieter in the area of the windows. It is clear that the noise is coming through the masonry. In areas where concrete pillars have been inserted, no noise comes through. There is naturally no planting around the house yet, as it is newly built.

What is your experience? Is this a general weakness of the bricks? And is it possible that the scaffolding, which is connected to the ground and the house wall, transmits the noise so clearly? And can we hope that with the completion of the exterior plaster, the masonry joints will be sealed well enough so that we will no longer hear the street?

I am very interested in your experiences/opinions

Regards
Patrick