Which stone / brick to use in solid construction

Sand-lime brick has a significantly higher density than your bricks or even aerated concrete. Accordingly, the sound insulation is considerably better.

However, keep in mind that the weak points are usually different, such as windows ..

And most sand-lime bricks are hollow inside to make it easier to run pipes vertically ...

No, they are for transpiration, so that the roof structure does not dry out...

Hollow? The 3DF has a handle hole, otherwise solid. Weighs around 7kg. The smaller one is 5kg or 4kg, it has no hole, it is a brick.

Small formats are hardly ever used on exterior walls today. The handle holes are usually oval and, in terms of sound insulation, are more of a reinforcement than a weakness. Mass equals sound insulation is the most naive milkmaid physics – but I have written that so often that I will not repeat it today.

Topic Noise Protection
Does anyone happen to know which walls are better for noise protection/sound insulation, the walls of wooden prefabricated houses (Danwood,Hanse Haus...) or the walls of solid houses (made of aerated concrete) from Town@Country houses?