Ever want to disguise your voice while making a prank phone call? Sure, if you're one of the Jerky Boys you can pretend to have an Indian accent and all, but if you're just not that talented then what you need is the Asterisk Voice Changer!

It allows you to change the pitch of your voice, or the voice of the called party in realtime, when making phone calls. Ah, the beauty of VoIP with the flexibility of Asterisk. Gotta love it!

The application, VoiceChangeDial, functions as a Dial() replacement except it allows you to change the pitch of your voice. But don't expect this Asterisk application to make a man sound like a woman or vice versa. According to their website, "It will however do a great job of masking your voice by making you sound either like a chimpmunk or Jabba the Hut."

It also explains one bit of a caveat - "Because this application needs to mangle voice data, it will need to pass through Asterisk back-to-back. This means that if you are switching SIP, the RTP will not pass from phone to phone, but will be proxied through Asterisk. Therefore, VoiceChangeDial() will use considerably more CPU and bandwidth than a normal Dial() operation."

But hey, what's a few CPU cycles for some cool Asterisk prankster fun?

The instructions are pretty easy so I'll include them here:

On your functioning Linux machine running Asterisk with the header files installed to /usr/include/asterisk, run the following commands to install the voice changer as well as its two dependencies:

# install SoundTouch 1.3.1
# you can also install it through your package manager
cd /usr/src
wget http://www.surina.net/soundtouch/soundtouch-1.3.1.tar.gz
tar xvzf soundtouch-1.3.1.tar.gz
cd soundtouch-1.3.1/
./configure --prefix=/usr
make
make install

# install libsoundtouch4c
cd /usr/src
wget http://www.lobstertech.com/code/libsoundtouch4c/releases/libsoundtouch4c-0.4.tar.gz
tar -xzvf libsoundtouch4c-0.4.tar.gz
cd libsoundtouch4c-0.4
./configure --prefix=/usr
make
make install

# install the voice changer
cd /usr/src
wget http://www.lobstertech.com/code/voicechanger/releases/voicechanger-0.6.tar.gz
tar -xzvf voicechanger-0.6.tar.gz
cd voicechanger-0.6
make
make install

# load it in to asterisk
make start

Be sure to check out this link on Lobstertech.com for the full list of options for this application. Now don't go using this voice changing application to do nefarious things, but feel free to have some fun with it.