My tinnitus is fairly loud in both ears. It seems to get louder when there's no other noise, occasionally to point of being nearly deafening. Sometimes I'll suddenly go deaf in one ear and hear a very loud metallic ringing for a moment before my ear seems to pop and go back to normal. My tinnitus is the type that is indicative of nerve damage (the ringing). A rushing noise is generally caused by the blood flow in your ears.