There are some foods to avoid if you want to minimize the volume or sound level of the ringing in your ears.
Mostly, you should avoid salty fast food and focus on healthy vegetables and use olive oil when ever you can. Try to eat plenty of fresh fruit and lean meat and fish. Basically if you eat a healthy diet that avoids preservatives and yes, avoids some of the good things in life like caffeine and alcohol, you will notice some reduction in the volume of your ringing ears. If you follow this diet, you will also reap other benefits like weight loss and when combined with exercise, you will burn fat off of your body. So, for a little sacrifice, you could really benefit while feeling great, looking great, and hearing better. That sounds like a winning combination to me.