Where is the "Music volume fade on phone/message notification" setting??

[Paraflam]

I can't find this for the life of me. My last iPhone faded out the music for a second when I was receiving a text message or phone call, but I just got a replacement phone and this one doesn't do that. How do I turn that feature on again? Thanks!

 

[QuarterSwede]

There isn't a switch as it's a native feature. If yours isn't working a restore may be the only option.

 

[Paraflam]

I could've sworn that with my original phone I was messing around with settings and I came across a switch for it, I could be wrong though. Is this a bug, do you think?