Apple® iPhone® - Turn Noise Cancellation On / Off

 Notes:

• If turned on, the Noise Cancellation setting reduces background noise while on a call.
• This setting isn't available on the iPhone 4. 

1. From a Home screen, navigate: Settings  > Accessibility.
    For devices running iOS 12.4 and lower, navigate: Settings  > General > Accessibility.
2. Tap Audio/Visual then tap the Phone Noise Cancellation switch to turn on or off .
    For devices running iOS 12.4 and lower, tap the Phone Noise Cancellation switch to turn on or off.