If the sound is cutting in and out/ has static sound/microphones don't work, pls reset the whole earbuds.1.Remove the T30 earbuds from the bluetooth list of your device2.Put both earbuds back to the charging case, then take them out from the case3.Turned on the earbuds, then tap the left or right earbuds 5 times until the white LEDs flash for 3 seconds4. Reconnect it with your device