a few years back, I was traveling at 70mph down the 55, heavy traffic, iPhone paired via bluetooth to my car. I was listening to music I think at a low volume.
Then, a sound as loud as an earthquake shook the car. I was beyond terrified. I jerked the steering wheel from the startle reflex and very nearly hit the divider.
It was of course, an Amber Alert, and an irresponsible one at that. I say that because it was for a county 300 miles north of where I was.
I don't know if it is still this way-- but the Amber Alerts used to play at full volume no matter what the phones settings are.
I am unsure of the wisdom of potentially startling every human being within a few hundred miles, at basically the same time.