wireless earbuds, mpow m9 4-mic noise cancelling cvc 8.0 bluetooth 5.0 earphones in-ear, touch control stereo bass sports headphones, 40h playing time/usb-c/ipx8 waterproof, single/twin mode, black mpow <p><b>what is 4-mic noise cancelling?</b></p> <p>the principle of noise reduction in calls is generally canceled by reversed sound waves, but we will also use voice enhance technology and beamforming technology to locate human vocal. beamforming uses two microphones to form an array to distinguish between noise and the direction of the human vocal, then eliminates noise.</p>