Looking for "Ambient Sound/Voice Recorder" activable by sound

[blackspawn2]

For security reasons I am looking for a software able to record ambient sounds/voices on my Kaiser.
I know plenty of normal sound recorders but I need one able to activate RECORD only when there is any sound in ambient...in other words a non continiuos recorder.
I will appreciate any suggestions.
Thanks in advance.

[blackspawn2]

I found Resco Audio Recorder. It seems a good one!