[CQ-Contest] Check # in SS

[Joe]

Now this is interesting.

I asked the below statement in another group. And did not get the answer 
I was expecting for sure.  Lets see what I get here.

Not to start up the controversy again of using a "Real" check number, 
that's been gone over on many sites, and the consensus seems to be that 
it doesn't matter what number you use, just as long as you are 
consistent in using it.

So that leaves the thought. With everyone trying to shave milliseconds 
off the exchange all the time,

What is the most efficient to use?

On CW now ignore "CUT" numbers, the shortest of course would be "55"
But would it also be the number that would be the easiest to understand, 
and minimize the ask for repeats?

Now ever harder on Phone?
Same question,, what would be the shortest to actually vocalize?
And what would be the easiest to hear? Again to minimize the ask for 
repeats. Or lack of possible confusion?
Plus, how about voicing fatigue?  What is easiest on the old voice-box 
so the voice doesn't fail towards the end of the contest?

Has anyone done any studies on this?

Joe WB9SBD