Deleting contact storage data worked for me.
It did end up clearing out some of the pictures that I had as well and replacing them with miniature portraits. Is there a good way to fix that?
I came here with the same problem. I do know that this is not an issue when I use the default Google Play Music app. That Google Play Music app does decrease the volume so you can hear the notification (on my Samsung Galaxy Note 3) I like some aspects of interface of the Samsung Music app...