Side Buttons

• The fastest way to control the volume on an iPhone is using the silver buttons on the left side of the phone. iPhone models 4 and later have two separate buttons on the side that are labeled with "+" and "-" symbols. iPhone 3GS and earlier have one long button, with a divot in the middle -- the top half turns the volume up, and the bottom half reduces volume.
  
  

Ring/Silent Switch

• Every iPhone has a ring/silent switch located on its left side just above the volume buttons. When turned on, the switch eliminates all sounds from the device, including ringtones. To turn the switch on, flip it toward the back of the device; when you see an orange dot, the silent mode is on. You can turn the switch on before you receive a call or in the middle of an incoming call to silence a ring that has begun.
  
  

Sleep/Wake Button

• The "Sleep/Wake" button is located on the top right side of your iPhone, and can also be used to silence a ring. When your iPhone starts ringing, press the button quickly one time to stop the ringing. If you hit the button a second time, the caller is sent to your iPhone's voicemail program.
  
  

On-Screen Controls

• You can also change the volume for your ring tones using the on-screen controls in the Settings menu. Choose the "Sounds" option. In the "Ringer and Alerts" section, use the slider to manually adjust the volume level. Moving the silver circle on the slider to the right increases volume, and moving it to the left decreases the ringer volume. Below the slider, toggle the "Change with Buttons" setting to "On" if you want to use the side buttons to control volume later.