Asterisk VoIP News

Monday, February 06, 2006

Asterisk native sounds now available!

Hello everyone,

As I promised at eTel last week, I have finished up work on my "Asterisk Native Sounds" project. Here's a little diddy from


Asterisk Native Sounds are a collection of audio prompts for Asterisk. They will improve quality, reduce CPU usage, reduce latency, and (in some cases) eliminate the need for G729 licenses! The Asterisk Native Sounds are a collection of alternative sounds prompts for Asterisk. Here's how it works. I had Allison Smith (the voice of Asterisk) re-record all of the sound prompts present in Asterisk 1.2. She provided them to me in the best audio format possible. I then converted them into several native Asterisk sound formats. Why would I do all of this?

The default audio prompts provided with Asterisk are in the GSM audio format. GSM audio is nice because it doesn't use much disk space. However, because GSM is a loss-based compression format, there is no way to recover the audio quality lost when they were converted to GSM. Also, because few commercial products (including phones) include support for GSM, you can all but guarantee that Asterisk has to transcode the
prompts when a device needs them (to access voicemail, for example).

With the Asterisk Native Sounds collection you will be using audio prompts with the same voice (Allison) as the standard prompts, saying the same thing as the the standard prompts. The only difference is that they are provided in several different audio formats (most with better quality) so that Asterisk doesn't have to transcode them to the format that is being used by the current channel.

Installation is very simple. Simply download the prompts to a directory on your Asterisk server. Any will do. Once you have downloaded theformats you desire, simple follow these steps:

cd /var/lib/asterisk/
mv sounds sounds.orig
tar -xvjf /path/to/sounds.tar.bz2
[repeat last step for other formats]

The audio prompts are available from the "Extras" category in the Downloads section of

While you're thinking about how much processor time you are saving and how much happier your users will be with better sounds, why don't you send me some money? Paypal donations are accepted at

Asterisk will immediately being using your new, high quality, audio prompts. Enjoy!

Kristian Kielhofner