audio-cryptoanalysis

Last winter I recorded a series of audio/video surveillance tapes at a house that I was visiting for a few weeks.
I was hearing barely audible voice out of thin air that scared me, but made me curious at the same time.
This is why I decided to secretly use a minature consumer level spy cam to make the recordings.
The recordings proved that what I was hearing in rea-time was captured on the recording device that I was using.
microSDHC media was used for the recordings, and the final videos was an .avi container recordings!

I have since converted the audio portions of the videos to .wav files to do further analysis of the audio using audio editing software like Audacity, and Cool Edit Pro, and have had some success in hearing some of the voices who talked in whispers. I am not an audio recording  cryptologist! Just an a freelance audio-video technician.
My questions to is what would a
audio-cryptanalyst use (software products) to analyze and make audio transcripts of the audio portion of the videos in questions!
If your warehouse sells these products please feel free to send me a list of these products.
Thanks