I've had more than one visit to the ENT to get scoped for hoarseness. It depends on the ENT what they will use. Actually, if the ENT has the equipment to do it 2 ways, it will depend on you as well.
When I went recently to an ENT/head,neck,throat surgeon they prepared me for the typical through the nose scope. They spray your nostril/nostrils with a Novocaine like substance so you won't be bothered as much. Once you've become numb, the doc threads a tiny wire/scope through your nose, and down your throat so they can get a look at your vocal chords.
A more revealing look can be made with a scope that goes through your mouth. I had that for the first time in the Fall. They wouldn't have done it on me if I couldn't tolerate it...that's why they prepared me for the regular through-the -nose scope.
This is how I remember that procedure:
The doc had me lean forward with my head back...to straighten the throat area. Then he held my tongue with a gauze pad and put a scope into my mouth toward the back of my throat. It doesn't go in far, but apparently some people can't tolerate that procedure. The good thing about it, is that there's a strobe that goes with it, so they can take pictures while they scope, and they can get still pictures when you make vocal noises, which shows more of what's going on.
Having had 3 endoscopies, a manometry, and wired PH monitor tests, I didn't find the test all that difficult. Again, they'd never make you do it that way...it just provides a LOT more information and much clearer pictures.
Don't worry one bit. It only lasts a short time.
Good luck with your test!