Hi Ellie. I've submitted a handful of audio poems here at Lit. The first ones I did were submitted on the 800-number. So to answer your question, yes they take poems.
(Sexy sounds, uh I don't know about submitting them here. Anyone who wants to hear my sexy sounds is gonna have to either a) be Al Pacino; b) deeply impress me on at least a few great dates; or c) did I mention be Al Pacino?)
I was not thrilled with the sound quality on the 800 number. It was fairly static-y, but maybe that was my phone. I rerecorded my submissions on the MP3 Sound Recorder, which you can download for free (a trial version) or buy for 15 bucks, USD. It's well worth it to buy, makes nice clear recordings and is very easy to use.