You can use the OpennetCF SDF Multimedia library to accomplish this
http://www.opennetcf.org/CategoryView.aspx?category=Home
> 1.How can I get the audio data from PDA earphone/microphone?
> 2.Can I find any tools to analyze the audio data?

Signature
W.G. Ryan, eMVP
http://forums.devbuzz.com/
http://www.knowdotnet.com/williamryan.html
http://www.msmvps.com/WilliamRyan/