Want to know what the tones mean. I seem to get three tones in the left ear when I click on the switch. The one on the right gives a different tone and turns sound up or down. It has the following numbers: CE 0123 and a 14NQ3267 number on the unit. My dome is an upgrade from the typical dish shape. It is easy to clean and has little wing like things to grab and use to twist into your ear. Got the Unit from the Veterans Administration..