Yea that may be the reason for the phonetical clarification. People got tired of saying it's close! it's close!
Tom: Hey Bob how far is the public bathhouse?
Bob: Oh it's close.
Tom: It is? I thought it was open?
Bob:
I didn't say it's close, I said it's close!!
Tom:
WHAT?
lololol
They probably just stuck on a D. Still thought I'd like to find out the history behind it you know? I'm going to check the big mama OED tonight, now if I only remember where I put the magnifying glass..