You may want to get an inline Level Attenuator from Shure, take a look at their accessories page. Whether you use in ear or headphone monitors, you need to be extra careful with the volume levels you expose your ears to, especially over prolonged periods of time. I wish Boeing and Airbus would do a better job in balancing the levels of their PA systems so that your ears don't get blasted out when announcements are made, especially on the headphone circuits. The technology is available, it just needs to be applied better.