Problem: Loud hissing sound while charging Note II.
Cause: Galaxy Note 2 is such a powerful device, that it has a really big 60Hz transformer. The hissing noise made by the charger is NORMAL
Solution: Charge via laptop/ PC USB port, but it'll take much longer to complete.
OR Try lower-rated charger will charge the device more slowly with less noise.
OR Charge in seperate room if the noise keep you awake at night
URL: http://www.samsungupdate.com/android-how-to/samsung-galaxy-note-2-common-issues
