[LAD] Audio Trigger

[OrazioPirataDelloSpazio (Lorenzo)]

Hi all,
I need to use a microphone input as a trigger. In other words my idea is 
to connect a switch to the microphone input. In this way, when the 
switch is turned on it generates a spike in the captured track.
I would like to create a program that trigger an event every spike it 
receives.

I succeed in capturing the mic input through a simple program that uses 
alsa driver, but I don't know how to "parse" the raw data to search for 
the spikes. Any hints?

Second question: on a "full duplex" sound card, can I capture at 8 bit, 
mono, 22.050 bit/s , and on the same time playback at 16 bit, stereo, 
44.100 ?

Thank you!

Lorenzo