Attached improved version of CallNotify.py that you need to copy over the existing version on /usr/lib/hildon-desktop

Remember to make backup of existing CallNotify.py if you want to revert back for some reason.

Changes:
- It uses playbin2 for playing sounds for missed calls and sms, and this means any sound file can be used instead of default one /usr/share/CallNotify/missed.wav
- If you want to use separate sound files for missed call, sms and both, you need to copy the attached sound.txt file to /home/user/.config/CallNotify/ directory. The file contain in order: first line is for missed call sound, second line is for missed sms sound and third line is for missed both call and sms sound. Of course you need to change the lines with your own sound files. Last line is volume in the range 0.1-1.0.

For playing mp3, I guess you need to install mplayer application.

I know it would be nice to put these settings in Settings-Call Notify instead of modifying sound.txt file, unfortunately I have no time for such changes and it works fine for me this way.

Also I have no user rights for pushing these changes as an update to the original application.