[VOIPSEC] creating virtual phones

[Robin Wood]

I'm thinking of putting Asterisk and a few virtual machines with soft
phones in my lab but for the soft phones to work they will need access
to a handset. I could get hold of a few real handsets and share them
over USB to each machine so each one has a real handset but I was
wondering, if the clients are running on linux, is there a way to set
up a device that I can just cat an mp3 or wav to to simulate someone
talking?

The goal of the idea is to have a script which will sit on both sides
of the call and either at intervals, or randomly, inject some noise
into the call so I can concentrate on capturing and playing with
packets and not have to worry about making real noise into real
microphones.

Can it be done?

Robin