Techniques for improving listening comprehension under background noise conditions I have noticed that there is a big gap between my listening comprehension under ideal conditions (f.e. listening to a chinese movie/TV show/ChinesePod at my computer) and real-life listening comprehension (f.e. listening to friends at a loud chinese restaurant or sometimes just stuff like listening to a clarification question after I ordered milk tea at a noisy street).

I'm sure most Chinese learners face similar issues and I haven't come across any good strategy how to tackle this. Since I do not live in China I do not get enough input to use the "just listen more under non-ideal conditions"-strategy. 

Do you have any suggestions/ideas?
Try your best. 

Similar to any language that being "localised", it took "origin" speaker time to adapt in order to understand different slang. E.g. A GB English speaker will have a hard time following Australian English, New Jersey slang, Mississipi slang.

If you watch series from PRC, it is mostly Beijing slang. If you don't understand most of the words speaking by some Chinese, then you probably hearing some sort of dialect, e.g. Shang-hai-hua, Guang-dong-hua ,etc.