It Worked!
Not what the OP said, but I officially made myself look crazy.
I had a text message notification on my lockscreen and while trying this out and it not working I got a little creative. I did a few too many home button clicks which enabled voiceover.
This otterbox seems to amplify the sound by 800 in this quiet place
Phone starts talking.. NEW MESSAGE FROM SO AND SO, VOICE OVER OFF, VOICE OVER ON, NEW MESSAGE FROM, VOICE OVER OFF.. Was in that cycle for what felt like an hour (15-30 secs) Yea I'm done with this one.