Fast charging on the Galaxy S7 is an awesome feature, but according to Samsung's user manual, it may make some noise. Thankfully you've got the option to turn it off. From the official Galaxy S7 user manual... How to turn off Fast Charging on the Galaxy S7 A fan inside the charger may produce noise during fast wireless charging. To reduce the fan noise, you must deactivate the fast wireless charging feature. The on/off option will be added in your device's settings menu when you first place it on the charger. On the Home screen, tap Apps —, Settings —, Battery, and then tap the Fast wireless charging switch to deactivate it. Deactivating this feature will reduce noise, but may result in slower charging times.