[Asterisk-biz] answering machine detection

[alex at pilosoft.com]

On Wed, 2 Mar 2005 alex at pilosoft.com wrote:

> > Has anyone worked on any code or have any experience doing answering
> > machine detection.  Someone I was talking to was telling me something
> > like normal callers do more mhz? :)  Which I assume maybe they mean
> > that a normal caller sends higher frequencies since its not
> > pre-recorded.  However I am wonder if the codec compression would
> > remove that.  Anyone out there have any experience with coding such
> > things or using them?
> No. There's a "standard" tone for answering machine (the "beep") - that
> can be detected. I doubt you can do any kind of detection simply based
> on voice frequency patterns.
> 
> This is not a -dev thing either ;)
Have to correct myself. Apparently it *is* possible to detect based on 
voice frequency patterns.

http://www.stratasoft.com/resources/docs%5Cwhite%20papers%5CAnswering%20Machine%20and%20SIT%20Detection.pdf

http://www.databasesystemscorp.com/acdreports.htm