Unable to detect beep using asterisk 10.8


I have asterisk 10.8 in our environment. Currently our amd is able to detect 80-85% of answering machines. For the remaining 10-15% we have calls were we can see a lots of calls with beeps which are not getting recognised.

I am working on the app_amd.c file to see if i can make any changes in this code to identify the fragments as beep. This is just the concept i have in my mind.

Please can anyone help me if this is the right approach and if so can i get any code which can help me get this achieved. Or please suggest a solution which can help me detect the beeps.

Thanks in advance.