on Android devices there is a sound and vibration feedback when using the keyboard (upon pressing keys). Disable vibration on Galaxy S4 keyboard and Note 3 by doing as follows:
1. Open Settings application and go to Controls tab
2. Open Language and input.
3. Under "keyboards and input methods", tap the settings icon next to Samsung keyboard.
4. Under "Key-tap feedback", make sure to disable Vibration.
Read More Galaxy S4 Tips and Tricks