In the medical and scientific community, tinnitus is dysfunctional nerve activity that manifests itself as phantom sound. For those who served in the military, tinnitus is the ringing, buzzing, humming, chirping and/or tones that you hear, after being exposed to a hazardous level of loud noise. The standard definition of tinnitus recognized by audiologists and otologists is from the Dauman and Tyler 1992 Tinnitus Handbook. According to the literature, a tinnitus diagnosis relies on the perception of sound in the head or ears, which occurs at least twice weekly, for a minimum of five minutes per episode.

You can read more about tinnitus here:

https://www.audiologyonline.com/articles/20q-tinnitus-options-for-clinical-28521