Setting that has been screwed with as a result of rogue programs or poor upgrades are also probable triggers. If your phone abruptly ceased making sound after installing a new app or software update, that app or software update is most likely to blame. In this situation, an all settings reset will remove all of your iPhone's existing settings, including any improper audio settings, and return them all to their original values or factory defaults. Here's how you do it:

1. From the Home screen, choose Settings.
2. Select General.
3. Reset may be found by scrolling down and tapping it.
4. Choose Reset all settings from the drop-down menu. Your existing settings will be reverted to factory defaults or the original setup.
5. If required, enter your device's passcode.
6. Then press the option to confirm settings reset.