As mentioned, everything will depend on what school(s) you're applying to, and what major. In high school I had damaged my voice by shouting too much so that I couldn't sing even into the alto range, which made auditioning very interesting.
For my music education audition I had to sing America the Beautiful, but I couldn't actually sing it in the key they asked, so they had to change it for me. At the same time, I had to listen to a cd of small passages and reproduce them on voice, which I also couldn't due because I couldn't sing the range. When I could I tried to jump octaves, but it was pretty hard to do, especially in an audition when you're not used to singing!
Regardless, the people could tell that I could hear the notes, and if I'd had the abilities I wouldn't have had trouble reproducing them, so they let me in. One guy told me to sing to the radio more
So, after a long story, I don't think the aural portion is going to factor too much into the equation, if I got into mus. ed. with no voice.
As for the performance part, I brought in a sonata, and a technical exercise that I had prepared before. It's probably different for others, but I was told to simply prepare stuff that would show the melodic and technical sides of playing.