I Hear A Hollow Wood Sound Inside My Head While

I hear a hollow wood sound inside my head while chewing and brushing my hair. I currently have ear a plugged ear problem for over a month where the ENT doctor told me to hold my noise and blow to unplug it because everything else I tried didn't work. A friend told me it might be TMJ while what I read is a Eustachian tube issue. I want to make sure there is nothing else wrong. It is very weird to have a hollow wood sound in your head.