No sound for video or audio, play audio in background
By default, your app only plays audio if the phone is not on silent mode.
If you'd like to bypass this setting and play audio even when the phone is on silent mode, you can add the Cordova Background Audio plugin.
Visit your app customizer Settings tab, and scroll down to PhoneGap config.xml custom code. Add this code:
<plugin spec="https://github.com/EddyVerbruggen/cordova-plugin-backgroundaudio.git" />
Rebuild your project and test on a device, it will now play audio even on silent mode.