As you know some notifications can be expanded by swiping down. If I do this on my I9195 (running stock 4.2.2), everytime a let's say crunchy voice appears. It gets more intensively if various notifications are there. In this case it also begins to vibrate, but not like a notification vibration, more just for the time my finger lays on the screen and is moving.
The same situation appears if I briefly press the voice message button in the messenger Telegram.
I strongly believe this is due to system tunes (phone is mute btw), but I haven't found out what it's causing this. Any idea what this creates and how to fix it?