Tinnitus is the perception of noises within the ear without an external source of the sound. Tinnitus can happen in one ear or the two, intermittently or continuously, and varies in pitch and intensity in different patients. Most times, the tinnitus noise is perceived as coming from within the ear. And at other times, it may be heard like it has an external source. The sound that you may experience when you have tinnitus is explained as a high-pitched ringing sound.