The landing site may be dry, but we might hear sounds
Such as thin Martian winds gliding across the ancients sands, or
perhaps a dust devil whipping ghostlike by, or maybe the sound of
wet leather scraping across the regolith, coming closer with each
passing minute....
http://www.universetoday.com/2008/10/01/phoenix-lander-will-listen-to-the-sounds-of-mars/