Noise floors

Ambient noise only becomes an issue above a certain level, although some noise is more invasive than other.

If you have an ambient noise problem arising either from your home or from outside, first big steer is to listen at night when noise is way down.

Second, choose the location of your room if you can.  Mine is in the basement of a stone built house.  With the system down my room is very very quiet.

If you have a/c, switch it off while listening, as in many theatres and concert halls.

Remember also that room treatments absorb sound coming from outside the same as sound coming from inside.

I do not understand all this, apart from identifying that if there is much snow on the ground outside, then the sound inside is great

The neighborhood had a power outage two days ago. The silence was deafening.

Frank

Others have said the same thing.  My view is you don't get many power outages!  I live in an area where they are common, and I assure you, after five minutes, every generator within listening distance fires up, including my own. It's like a symphony of bad lawn mowers.

Tyre/ road noise far worse than anything else for me (has got worse over the years with wider and lower profiles and more traffic)- no-one seems to have done much about it

Apart from that  the weekend motorbike groups with their stupid loud pipes.

I'm not really sure I agree on the greater the system resolution, the less ambient noise floor should matter. As I've attained ever increasing levels of resolution, the more these ambient noises bother me. I tended to listen at higher volumes when system less resolving. Also, as my system's dynamics, resolution, transparency have improved I"m listening to much wider range of music genre, greater macro and micro dynamics mean quiet passages are that much quieter (system wise), higher level of ambient noise means I can't make out those minute micro dynamics quite as well as the macro, this phenomenon is very noticed in my room and system. Lower ambient noise levels would allow that minutiae to be heard better. At the level of system resolution I'm talking about every single little link in chain matters. I'd suggest listening room may be single most important component in audio systems. Even though I have dedicated listening room that's been judiciously treated with room acoustic devices, I'd now consider my room to be the weak link in system.

And I often hear the old adage, my system sounds better late at night. Usually you hear cleaner AC as the reason for this improvement, I'd also suggest it may have as much to do with lower ambient noise floor in listening room. Much less human activity, all activity makes some level of noise.

As for the snow thing, do you know that snow can be an insulator, ever heard of snow forts, may save you if lost in wilderness. Tires over pavement much louder than tires over worn down snow, yes, new snow will make crunching sound, not worn down snow. And if piled up around house may reach quite high on first floor of house, this insulates the house somewhat. And then we have much lower traffic volume and decreased speed during snow events. For many of us, traffic noise is likely the bulk of what makes up this ambient noise level.