asterisk users - Nov 2006 - Play an announcement while receiving DTMF?

I have a customer who wants their Asterisk system to play an announcement
to the caller while a DTMF string is being sent from the caller's phone.

As far as I am aware, this isn't possible: it's only possible to detect
DTMF if the first incoming digit interrupts the announcement.

Is that correct? Is there any way to achieve what the customer is asking
for, or is it an unrealistic request?

Thanks in advance for any advice.

Cheers
Tony
-- 
Tony Mountifield
Work: tony@softins.co.uk - http://www.softins.co.uk
Play: tony@mountifield.org - http://tony.mountifield.org