Android 8.1 limits notification sounds to one per second for every app - Android Authority
How to change notification sounds on your Android device - Android Authority
Customize Notification Sounds on Android Oreo - VisiHow
How to change the notification sound on your Android phone | NextPit
Android O: How to Use Notification Channels
Notification Channels in Android Oreo
Custom Sound not playing in Android version 8 (Oreo). Plays default sound for local notification · Issue #1605 · katzer/cordova-plugin-local- notifications · GitHub
4 Ways to Add Notification Sounds on Android - wikiHow
How to Change Android Notification Sounds
Customize Notification Sounds on Android Oreo - VisiHow
Customize Notification Sounds on Android Oreo - VisiHow
Android Q adds a new Notification Assistant API to manage notifications
Get Android Oreo's Notification Shade on Any Phone — No Root Needed « Android :: Gadget Hacks
TutorialsBuzz: Android Play Notification Sound From Different Resources
Android Oreo Notification Channels
How to Change the Notification Sound on Your Android Phone - Make Tech Easier
Get Android Oreo's Notification Shade on Any Phone — No Root Needed « Android :: Gadget Hacks
Custom Notification Sounds for Android Oreo and Beyond | PagerDuty
Get Android Oreo's Notification Shade on Any Phone — No Root Needed « Android :: Gadget Hacks