Interrupt th IVR greeting

Hello
I have trixbox 2.2, freepbx 2.2.1.
I setup an IVR, with an announcement, and checked the “Allow Skip” option
When users call, I am getting 50% rate of successfully interrupting the greeting message. If the caller is using a cell phone, then the chance is 0% to interrupt the greeting.

Any suggestion

Thanks

sounds like a dtmf detection issue, you’ll need to investigate that further and for starters, if using any VoIP trunks make sure you are using only linear codecs like ulaw/alaw.