ᐅ Sound insulation for windows: Why is it important?

Hello everyone,

I have not been able to fully understand the significance of the sound insulation rating of windows in relation to external noise protection compared to the masonry.
There is sometimes criticism of hollow bricks due to their poor sound insulation, as they only have a sound reduction index of about 40 dB.
However, when I look at the data sheets from well-known window manufacturers, I find sound insulation values significantly below 40 dB. Only with specialized soundproof windows are values up to 43/44 dB achieved.

So, what is the point of considering the sound insulation of the bricks as a criterion if, as a rule, they are already better than the windows?
Or am I misunderstanding something with my "weakest link" thinking?

Best regards,
ufr123

No, you understand that perfectly. Especially since the brick will also have a 2cm (approximately 0.8 inch) interior plaster layer and a three-layer exterior plaster system.

The reason hollow chamber bricks are sometimes criticized regarding sound insulation is mainly because they are not suitable for multi-family houses. Sound can travel more easily between floors within the building.

This is not as significant an issue in single-family homes.