Well, TOKKERS does that for a price :(. As an educator in Brazil, I'm always looking for webtools and apps which are FREE so that they can be used to promote learning.
All things considered, in order to make an audio qrcode, I end up having to use two different tools: one to record and host the audio and another to generate the code.
So first, I used my AUDIOBOO app to record myself reading a poem and then grabbed the audio URL.
Then, I used http://qrcode.kaywa.com/ to generate the QR CODE and saved the image.
So, if you scan the code with you cell phone, you'll be able to listen to the poem.