I have the HTC One M8 which now has Android 4.4.4, and I would like to change the notification in Yahoo Messenger when I'm not in a conversation to a custom notification sound. I use the "Yahooooooooo" sound because the default is to difficult to hear, and the default notification sounds I tend to ignore thinking it's something else. Is there a way to do it? On my old phones I had root access and was able to copy/paste the mp3 to the folder and it worked. I don't have root access on my new phone, and it only shows the default sounds. Thank you.