Summary:ASTERISK-08757: SpeechBackground: Stop Speech Rec after DTMF received
Reporter:surftek (surftek)Labels:
Date Opened:2007-02-08 15:48:37.000-0600Date Closed:2007-06-30 09:19:59
Versions:Frequency of
Environment:Attachments:( 0) dtmfblip_actual.wav
Description:Directed here by Lumenvox and Digium support:

Trying to use SpeechBackground to either recognize speech, or detect dtmf -- the user is given the option of doing one OR the other.  Though SpeechBackground provides this support, there is a problem/bug which makes receiving multiple character dtmf strings very unreliable.

We're using Asterisk 1.4 and receiving SIP calls via a 3rd-party SIP/PSTN gateway with DTMF reported via RFC2833 DTMF events.  It seems a natural result of this setup (and as found with 5 of 6 providers), is that a short 6-20ms blip (see attached WAV) resulting from a partially clamped DTMF tone is received IN ADDITION to the RFC2833 event.  The speech engine via SpeechBackground detects this blip as speech, matches it with a 1-syllable grammar entry (i.e. car, ed, etc), and returns that as a result interrupting the user as they input a multiple character DTMF string.

I tried modifying the lumenvox.conf settings, even to extremes, with no success.  I have also contacted Lumenvox support.  They instructed me to talk to Digium Support.  Digium Support suggested filing a feature request.

As soon as SpeechBackground receives DTMF, it should ignore any results from the speech engine (or stop passing audio frames) and wait for timeout or a '#'.  

Comments:By: Joshua C. Colp (jcolp) 2007-02-15 18:54:25.000-0600

Fixed in 1.4 as of revision 54714 and trunk as of revision 54715.