Default Sound selection for android push notification


I have an android app developed using ionic v1 platform. Currently i have implemented default push notification for
recieving push notification. I am planning to select custom sound of present in the mobile device. I do not want to
use fileselector which opens a file selection dialog

Could you help me in belwo two queries:
a. How to open custom sound file which will only show default sound files in ionic app using either cordova or phonegap?
b. Where should the sound file be placed in the ionic folder structure, so when notification comes on device
the sound should be placed.