When you first bring home your new iPhone, you'll hear a clicking noise each time you use the keyboard. If you don't like this sound, you can easily disable it using your "Settings" menu. If you hear clicking while completing tasks other than typing -- or while the phone is idle -- it could indicate a problem with your device.
All new iPhones are set to click whenever you use the keyboard. Each time you tap a key, you should hear a sound meant to emulate the clicking of a computer keyboard. All keys are assigned the same clicking noise, the volume of which is determined by the overall volume level you set for your iPhone. If you set it to silent, the clicking is temporarily silenced as well.
Disabling Keyboard Clicking
IPhone clicking doesn't serve any practical purpose; if you elect to turn off these sounds, the keyboard still functions perfectly well. To disable keyboard clicks, visit the "Settings" application on your iPhone and select "Sounds." Scroll to the very bottom of the menu and tap the "On" icon next to "Keyboard Clicks" to toggle the setting to "Off."
If your iPhone makes a clicking noise unrelated to the keyboard, such as during a phone call or while charging, the issue relates to your specific device. Resetting your device will force it to reboot and often fixes miscellaneous issues. Reset your phone by pressing and holding the "Sleep/Wake" and home buttons simultaneously until it powers down. After about 10 seconds, press the "Sleep/Wake" button to turn the device on again. If the problem persists, take your iPhone to an Apple store or visit the Apple website to find out how to send your device for service via regular mail.
While the iPhone has keyboard clicks enabled by default, the sounds make it quite challenging to create a text message or email discreetly. If you are in an office or classroom setting, turning off the keyboard clicks is a good idea. If your iPhone needs service because of other clicking sounds, your repairs are free if you have it serviced within 12 months of purchase.