What would you say is the definition of 'everyday noise'?

I'm currently in the middle of a dispute with my neighbours downstairs about us practising clical music in the flat upstairs - we play the piano, violin and cello. Admittedly the walls are thin so apparently the sound is very loud. We've been writing letters to each other trying to come to a compromise. In their last letter however, they've said that everyday noise is that which is not intrusive to someone else's life. Does anyone agree? I thought everyday noise was simply any sort of noise that happens throughout the day. If you think about it, us practising clical music is simply everyday noise to us but it's only a new type of everyday noise to them surely? I don't know - of course I can't be entirely objective about this so what does anyone else think?