If you're on pc and you spend plenty of time in a certain type of area, there are some ambient sounds on youtube that can help increase immersion. If you're using chrome, you can install a youtube looper extension to loop it as needed. (I like to play these along side some mixed in music at times.)
For when you're out in the city:
(I used to use another one by the same uploader for "lower city" but it sounded too quiet for what I think is supposed to be a more typically crowded area).
For when you're at a bar:
If anyone has anymore, we can share them here (assuming we can at least).