I normally would just ask my wife to make the calls for me. But today I had to make the call myself to credit card fraud investigation department because they needed to make sure it's really me.I tried to explain my condition to the other party (a nice lady) first in a couple of sentences, and I found doing so seemed to make the phone call less dreadful. But I can imagine if the other party is not so nice and does not care whatever speech disorder we have, the explanation probably won't help at all.