[asterisk-users] detecting a "beep"

[Julian Lyndon-Smith]

at the moment, if our agents make a call and they get an answering 
machine they have to wait for the "beep" before leaving a message.

I would like them to be able to transfer the call to an extension where 
an automated message can be left as soon as they know it is an A/M. 
However, how do I know how long to wait before playing back the message 
? Is there a "beep detector" function ?

Julian.