Sound insulation in timber frame construction. Recommendations?

Attention, purely a layman's opinion: The frequency range of human speech lies between 2 and 4 kHz. You would like to dampen this as well as possible without heavy filling of the space between the joists? Well, the highest sound insulation is achieved with good decoupling of the layers (not possible anymore? or is a suspended ceiling underneath still possible) and also sufficient damping of the cavity (to avoid standing waves). For this, the intermediate space should not be completely insulated (similarly to partition wall panels being thinner than the wooden frames -> 6 cm panels in 10 cm walls = approx. 60%). The upper floor structure is already quite suitable for damping impact noise!

Attention, all layman’s opinion: The frequency range of human speech lies between 2 and 4 kHz. You want to dampen this as well as possible without heavy filling of the cavities between the joists? Well, the highest sound insulation is achieved with good decoupling of the layers (no longer possible? or is a suspended ceiling underneath still possible) and in addition sufficient damping of the cavity (to avoid standing waves). For this, the cavity should just not be completely filled (similarly, partition wall boards should be thinner than the wooden frames -> 6 cm boards in 10 cm walls = approx. 60%). The upstairs structure is already quite suitable for damping impact sound!

How about the walls from room to room? Currently: gypsum board, OSB, 10 cm wooden studs, OSB, gypsum board.

Should this also be filled with cellulose, for example?

simply insert 6cm partition wall panels (mineral wool, approx. €2-2.5 per m²) - done (unless everything is already closed, then we leave it as it is ;))

Why shouldn't the ceiling be insulated? In my timber frame house, that was standard from the beginning. Rafters with wood fiber insulation/OSB/blow-in insulation/screed/floor covering. The rafters are still visible and only half insulated. You can still hear almost every step upstairs. I hope it's because of the "cork" laminate, which I can throw out in 10 years.

Why shouldn't the ceiling be insulated? In my timber frame house, that was standard from the beginning. Rafters with wood fiber insulation/OSB/filling/screed/floor covering. The rafters are still visible and only half insulated. You can still hear almost every step on the upper floor. I hope that's because of the "cork" laminate, which I can throw out in 10 years.

A complete elimination of impact sound from the upper floor to the ground floor will never be achievable. But if you can hear every step clearly, something is wrong. Probably a construction not optimized for sound insulation? My little experience with my own buildings, from conversations with architects etc., is that often too little value is placed on this (sometimes not even meeting the minimum requirements for rental apartments or multi-family houses). Improving this situation afterward is always very difficult and expensive :rolleyes: