It’s been a long-running accessibility feature on past iPhones.
Apple’s “Noise Cancellation” accessibility feature has been a staple on past iPhones, but may have been permanently removed from the iPhone 13 series, 9to5Mac has reported. The feature is designed to “reduce ambient noise on phone calls when you are holding the receiver to your ear,” a feature that can help make calls easier to hear.
“Phone Noise Cancellation is not available on iPhone 13 models, which is why you do not see this option in [the Accessibility] settings,” Apple support told one of 9to5Mac’s readers. When the reader asked for clarification, the support team confirmed that the feature is “not supported.”