Computer to walkie talkie

[Alex Kizub]

I have computer in the basement and I want to know when something
happens - for example I have invitation to chat or Skype is ringing.
So, actually, I need some kind of sound transfer to some kind of
wireless device what I can carry with me.

Walkie talkie would be good (cheap and in good range) but who will
push the button when sounds come?
If it's always on transmit mode then batteries would be dead in few
hours and I suppose to listen fan's noise all the time.

Is there some cheap device which I can connect to the audio output and
it transfers only this output when it exists?
Or, at least, something which is listening for sound and transfers it
to wireless remote receiver only when sound goes beyond some limit?