RE: attached icetray.jpg You'll need a fridge ice tray. Insert the stainless steel wires as shown in the attached icetray jpg. Notice the protruding wires shown on the right of the tray in this image. HEADSTART: select your most sensitive sensor. Listen using headphones and test by firmly placing your sensor, using removable tape, to the area where you can hear faint sounds. That done, check another sensor as you'll be needing two. Now. Select and carefully attach your 2 separate and shielded sensors to the steel tips. Use 2-very small plastic tie-wraps and make firm the two parts as snug as one (to avoid rattles, snip off tiewrap ends).

Find two same-size pieces of pliable foam an inch or so thick and create a 2 piece sandwich that will completely enclose the top and bottom of the ice tray. (The 2-piece foam serves as an acoustic-vibration-isolating wrapping and should be secured with rubber bands at both ends. Be careful that the foam sets above the water cups and does not contact the wire tips! (this could dampen the vibrations traversing the wires). With both wires in place, seal the ends with hand-warmed wax or some putty.

POST CONSTRUCTION: Decide your cabling route. What would be the best path and a useable location (nearest computer, HD/w/headphones). Lengthening your line output cabling could allow you more distance from the fridge.
CONSIDER THESE OPTIONS: optimise sensor sensitivities by directing their outputs to battery preamps, amps, line outs and computer/HD speaker/headphones. Input PicoCricket? ((The blue and red sensors shown in the original Frost printer, lower right window, were very high output crystals and these had to have potentiometers -a volume control- to prevent excessive loudness and distortion. These were best used during the very early stages of frost formations and their spreading; however, they don't pickup mid-range audio frequencies))
TO EXPERIMENT WITH ANALOG SOUND: Fill tray with water. Enclose tray with foam and wrap with rubber bands. Place in freezer. Direct the output cables to the location you've selected.
Scale wise, these freezer sounds might be as subtle and on par with atmoSferics. Hear Sferics here. http://www.spaceweather.com/glossary/inspire.html
AUDIO: The freezing process could begin at anytime and will depend on what the fridge settings are. Be sure to listen with headphones. Or do a direct to hard drive recording. Name and do save as.
Repeat this monitoring process as above by setting the whole package outside the freezer. Name and do save as.
INTERNET FEEDBACK,CRITIQUE W/Q&A: following the posting of selected and extended mono (economical) sound files.