When designing mobile media apps (specifically audio-only ones), what should they do when a notification comes in and phone volume is on?
I noticed two different behaviors on my phone - Spotify will pause the track, sound the notification, and then resume the track, while Pandora will lower the track volume to about 30%, sound the notification at full volume, and then resume the track at full volume. (If the phone is on silent or vibrate, the phone will vibrate or make no noise, and the track will continue playing at full volume).
Which one of these behaviors provides a better user experience?