Closer than that in some places. I'm from Sunderland, which is contiguous with Gateshead, and then Newcastle. I can clearly hear when someone is from Sunderland vs. Newcastle, although 'a foreigner' - say, someone from London - might not be able to pick it.

I dare say Liverpudlians and Mancunians and Glaswegians and so on would make the same claim.