In many people with tinnitus, the cause is not known. The ear is otherwise fine. What seems to happen is that signals are sent from the ear down the ear nerve to the hearing part of the brain. The brain interprets these signals as noise. It is not clear why these signals are sent from the ear.
Octane booster is  a product which is designed to rise the octane rating of the fuel. The main idea behind using boosters is to increase power and also vehicleâs efficiency in certain engines. These have anti knock additives which when added to fuel prevent the onset of knock (detonation or pre ignition).
Owner's manual: Unleaded premium gasoline, pump octane number 91 or higher. Use of lower octane gasoline can cause occasional metallic knocking noise in the engine and will result in decreased engine performance. Use of gasoline with a pump octane less than 87 can lead to engine damage.. 2013 Chevrolet Volt.