Being on a corner plot, we can easily hear people in 4 or 5 gardens, many of whom we've never met as it is their back garden backing onto our back garden with fences & hedges in between.
One family has, I guess, a pre-schooler. It was his birthday a couple of weeks ago and he had a swing. Much excitement! He has been trying to learn to swing himself with his parents regularly saying "you've got to move your legs in and out not just say "legs out; legs in"". He seems to have nailed it this weekend!
Another family have a baby who seems to gurgle and chuckle a lot and just sounds very contented with life.
Someone a bit further away has a competent pianist (although I'd quite like them to move onto another piece). I'm less enthusiastic about the violin playing as they're still at the very screechy stage.