This is highly subjective stuff, but I like the ship's engine noise videos, like this one: https://youtu.be/vuZ4uP279oc https://youtu.be/vuZ4uP279oc I also use

This is highly subjective stuff, but I like the ship's engine noise videos, like this one: https://youtu.be/vuZ4uP279oc https://youtu.be/vuZ4uP279oc I also used the generation and effects features in Audacity to make my own tracks, a few years back. I quickly ended up with some things I liked. Mix in some recordings from Freesound and you can arrive at professional results quickly. Finally there are some apps that function like mixers of existing sounds, and you can mix up your favorite combinations. I have used the Ambient Mixer app as well as some others and they offer a great range of sounds. Edit: And if your neighbors are partying too loudly, any of this stuff plus a reasonable pair of speakers will often immediately cancel the sound.