To run ethestra you will need a few dependencies.

The first is portmidizero which can be found here 

http://pypi.python.org/packages/source/p/portmidizero/portmidizero-0.1.tar.gz

The second item you will need is scapy, which should be installable via
the normal methods.

The third item is ZynAddSubFX, which again should be available from
normal channels.

There are two patches that you need to make, one to portmidizero and the 
other to scapy.  portmidizero, because on running it, it crashed on my
ubuntu box and refused to do anything because of an invalid type.  Scapy 
requires a patch to get the sniffer thread to quit.  This patch was first 
proposed on google code.

Once those patches have been applied, you will need to run up ZynAddSubFX.
This is the part that actually generates the noise.  You will see a .xmz
file in the Ethestra source tree.  This has parameters for ZynAddSubFX that
work well with the Ethestra defaults.  This can be loaded from within ZynAddSubFX.

Then run ethestra using

sudo python ethestra.py

We need to run as root to allow scapy to read the network traffic.

Enjoy.