When and why did we start using mike instead mic?

Answer 1

If people are simply writing "mic." (usually with a period!) as an abbreviation for "microphone", that's fine.

But if you turn it into it's own word (including when you are talking about the nickname for "Michael"), then by ordinary rules of English spelling, "mic" (or "Mic") would be pronounced the same as "mick" (as it is in mimic, frantic, panic, etc), that is, with a short i-vowel. But that's not how we pronounce it in mic(rophone) or the most common nickname for Michael -- we want a LONG-i.

The ordinary way to indicate a long-i at the end of a word is to add and e to the end. But simply doing that won't work with "c", for two reasons:
1) we already have a word "mice" that means something else! And, more basically,
2) c followed by e [or i or y] is typically pronounced "softly", that is, like an "s" (as IN mice, ice, ace, deuce, etc), whereas what you want is the 'hard-c', which IS pronounced like "k".

So that standard solution WHENEVER you want to make sure the c is to be read as "hard" (like a "k") and not "soft" (like an "s")

"Mike" is perhaps the best example. But there's also "bike" (from bicycle) and "nuke" (from nuclear). (Note that in the original words 'c' is a soft s-sound before the y-vowel of 'bicycle', and a hard k-sound before a consonant in 'nuclear'.) Compare shortening "Coca cola" to "Coke"

Another example is the ADDING of a k after the c, esp. before endings that start with a vowel, to indicate that the i-vowel is SHORT. That's what happens with "Mick" (and Rick, Dick...), as well as with words like mimic and picnic when you add -ing, as in "picnicked", "mimicking".

Answer 2

not sure all ive heard of was mic.. which is the proper and most used term have no idea where your from

Answer 3

because mic is a short form of microphone