Kind of interested for someone to look into if hearing children noise is healthy, I could imagine it actually affecting one's hormonal response and such, but also maybe not.
No. I thought it was widely known that kindergarten employees suffer from earing loss due to repeated exposure to high sound level from the screaming kids.
Anecdotally, children making "children noises" is calming for me.
It was not until after I was a parent myself though. Like many things in life, once I had the connection in my own personal life, it is now very easy and automatic for me to empathize and support other children. It feels deep, like more an automatic response.
Can't exactly remember how I reacted to children noises before I had kids myself. But I must admit that nowadays noise from other kids makes me smile because 'not my problem'.