CMF Headphone Pro supports Active Noise Cancellation (ANC) with a maximum depth of 40dB. We recommend downloading the Nothing X app and navigating to Noise Control to check your ANC settings. The app offers multiple options including High / Mid / Low / Adaptive modes.
Please also ensure that the ear cushions are properly sealed around your ears. A poor fit can affect the air-tightness and significantly reduce noise cancellation performance.