Tinnitus Tinnitus Tinnitus is the hearing of sound when no external sound is present. While often described as a ringing, it may also sound like a clicking, hiss or roaring. Rarely, unclear voices or music are heard. The sound may be soft or loud, low pitched or high pitched and appear to be coming from one ear or both. Most of the time, it comes on gradually. In some people, the sound causes depression or anxiety and can interfere with concentration. Tinnitus is not a disease but a symptom that can result from a number of underlying causes. One of the
Black-body radiation logically determined solely by its own internal state. The causal effect of thermodynamic absorption on thermodynamic (spontaneous) emission is not direct, but is only indirect as it affects the internal state of the body. This means that at thermodynamic equilibrium the amount of every wavelength in every direction of thermal radiation emitted by a body at temperature "T", black or not, is equal to the corresponding amount that the body absorbs because it is surrounded by light at temperature "T". When the body is black, the absorption is obvious: the amount of light absorbed is all the light that hits