[Freeswitch-users] mod_vmd--can it do more than simply find VoiceMail Beeping?

[David Knell]

On Tue, 2009-04-07 at 17:17 +1000, Jason White wrote:
> Matthew Fong <mattdfong at gmail.com> wrote:
> > My question is, is there a way to use mod_vmd to detect if an answering
> > machine or human has picked up within the first 1-2 seconds after being
> > answered? 
> 
> Probably not. If you have an algorithm in mind that would achieve this with a
> high degree of reliability, I'm sure the FreeSWITCH developers would be
> interested in it. However, as far as I know, there is no reliable way to
> distinguish, for example, my voice as recorded in a voicemail greeting from my
> voice giving a live greeting after answering a phone call. Think about it.

The usual way is to measure how long the person who answers the phone
speaks for.  A person might say "Hello?", "Hello, this is Alice",
"Thank you for calling XYZ.  How may I direct your call?"  Voicemail 
will usually be longer - "Hi, this is Bob.  I'm sorry I can't take
your call right now, so please leave me a message after the tone and
I'll get back to you as soon as I can."

In the first couple of cases above, this would give you an answer - 
"human" - within the first few seconds of the call.

FreeSWITCH will give you TALK (start of speech (or noise)) and NOTALK
(end of) events if you enable VAD.

--Dave