Ice is building up on the fan that is behind the ice maker. Causing fan to make noise, due to fan blade hitting ice buildup.
If all the coils are packed with ice it sounds like you have a defrost problem. There are only three components that make up the defrost system in a refrigerator, the defrost heater, the defrost thermostat and the defrost control board or defrost timer. The best and easiest way to check the defrost system is: Remove the evaporator cover (freezer section back wall) and check the defrost heater and defrost thermostat for continuity with an ohmmeter. Check the defrost thermostat while it’s covered with frost. It needs to be below 40*F to show continuity. If both check OK for continuity, the defrost control/timer has failed and must be replaced.