my phone just started doing the same thing a few minutes ago. I have my earbuds plugged in and it first started when I checked my email. Now it won't stop. When I try to listen to music on Youtube, I can hear it over the music I'm trying to play. I deleted all my saved alarms, silenced the timer, etc., I checked pretty much everything I could that I thought might be causing the noise. I even closed all of my tabs. Nothing worked. Even when my phone is locked, I can still hear it. I also tried unplugging my earbuds and plugging them back in. The only thing I haven't tried yet is turning my phone off then back on.