I have the ringer silenced, and interruptions are switched to "none." All my notifications are turned off as well. Then, if I get an incoming call and don't answer, it makes a dropped call beep. I am trying to stop it from making this noise, even my media volume is turned all the way down. I would like to turn off all noises on my Droid Turbo 2.
I usually have my phone on silent while at work and I don't recall even having a beep sound after a missed call.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.