Hello, I have a hollow sound in my head where I can actually hear myself breathing and when I speak, it sounds extremely muffled to me. I have to ultimately rely on my years of speaking to gauge how my words are actually sounding to the person or people I am talking to, hoping they understand. I have spoken to my oncologist about this (I had nasalparyngeal carcinoma as a child), and he relates this to my chemo or radiation treatments. I am 44 years old, 5'3 and 155lbs.. There has to be a remedy to correct this, it's driving me CRAZY!!! I have tried the suggested lowering my head to my knees for approximately 30 seconds, but the fix is temporary (if at all). Please, please help me.