Well, in my case, where there's a will, there's a way...I'm totally deaf, but still speak....and whenever I go to to a fast food place take-out...I put my hand on the speaker and feel the vibes asking for the order....then I place it..and repeat it twice. It shows up on the screen...and if there is an error, I correct it....I've done it for years.
As for Sonic...if that doesn't work, or if you cannot speak clearly, then just wait for one of those skaters to come by, let them know you're deaf and they will take the order for you...Here in Jax, you are not allowed inside their restaurant, you have to order from the speaker, or the skater that brings ur food out. And they have been very accomadating to me.
As for the OP...you cannot expect all restaurants/stores to conform. Do all of them have Braille for the blind?....even other disabilities.....