[Asterisk-Users] Multi-line TTS Outbound Dialer

[Carl Youngblood]

Hello,

I've been lurking around the mailing list and browsing around on 
Asterisk-related links while I wait for my X100P to come in the mail.  
So far I haven't found very much information related to what I want to 
do with Asterisk.  I was wondering if someone could point me in the 
direction of any work that may already have been done on a project 
similar to the one I'm trying to do.

I'm interested in creating an outbound dialer application that will 
leave voice alerts with our customers.  I want it to select a list of 
phone numbers and accompanying text messages from a PostgreSQL database, 
use a TTS engine to convert the text messages into audio files, and use 
all available lines to send out the messages as quickly as possible.  I 
also want to make sure that it works with an answering machine.  After 
looking into a number of cheap dialer apps that only support half-duplex 
voice modems, I found Asterisk and the accompanying hardware at the 
Asterisk store, which I'm told supports full-duplex audio.  As far as I 
understand it, full-duplex audio is necessary to detect answering 
machines well.  This is what I have in mind for the answering machine 
detection algorithm:

1) Dial the number.
2) Wait until line is picked up.
3) Wait until 1-2 seconds of relative silence (silence threshold will 
require some calibration).
4) Begin leaving message.
5) If during message, noise is heard coming from the other end, stop 
sending message and loop back to step number 3.
6) After leaving message successfully, hang up.

Anyway, if anyone could point out any work that has already been done in 
this regard, I would really appreciate it.

Thanks,

Carl Youngblood