Reading mumsnet threads and talking to friends, neighbours, etc it seems obvious that noise - particularly noise from neighbours - is a big problem for many people and can have a significant impact on people’s physical and mental wellbeing. I have experienced this issue from both sides - having a downstairs neighbour complaining about hearing footsteps during the day, and in my current house having had parties/loud music from a next door neighbour.
I have lived in other countries where it hasn’t been such an issue because house/flats are more solidly built and/or there are stricter laws about noise.