What does he mean by “ends up in the brain”? Essentially, something that causes even temporary hearing damage — such as exposure to very loud noise or a blow to the head — can change activity patterns in the brain in ways that cause the ringing. Even though some damage or problem in the ear triggered tinnitus to begin with, you continue to hear the sound you do because of a signal from the brain.
Objects or insects in the ear can be placed in the ear by patients themselves, or an insect crawling in the ear. Ear wax can also cause ear problems if Q-tips are overused to clean the ears. Symptoms of an object in the ear are inflammation and sensitivity, redness, or discharge of pus or blood. When to seek medical care for an object or insect in the ear is included in the article information.

A common cause of tinnitus is inner ear hair cell damage. Tiny, delicate hairs in your inner ear move in relation to the pressure of sound waves. This triggers cells to release an electrical signal through a nerve from your ear (auditory nerve) to your brain. Your brain interprets these signals as sound. If the hairs inside your inner ear are bent or broken, they can "leak" random electrical impulses to your brain, causing tinnitus.