http://www.macalester.edu/psychology/whathap/ubnrp/smell/memory.html, last paragraph and this:
Olfaction is the sensory modality that is physically closest to the limbic system, of which the hippocampus and amygdala are a part, and which is responsible for emotions and memory. Indeed this may be why odor-evoked memories are unusually emotionally potent (1996).
http://serendip.brynmawr.edu/exchange/node/1751 hal;fway down ctrl+F smell and memory
"Smell evokes memory in a way that no other sense can"
http://64.233.169.104/search?q=cache:2WUYDuGbPqQJ:www.cas.uio.no/Publications/Cas04no1/screen.pdf+smell+memory&hl=en&ct=clnk&cd=6&gl=us
i can't quote anything from there for some reason.
memory and hearing
http://psychcentral.com/news/2008/07/22/memory-impairment-linked-to-hearing-disorder/2647.html
http://staticdisposal.wordpress.com/2006/12/28/sound-memory-intertwined/
http://www.medicalnewstoday.com/articles/12721.php
this last one states how both sight and sound are crucial in short term memory, but that sound outperforms sight a little more than slightly.