Tinnitus tests are suitable when tinnitus occurs with the same rhythm as the heartbeat. Rarely, the sound may be heard by someone else using a stethoscope, in which case it is known as objective tinnitus. Spontaneous otoacoustic emissions, which are sounds produced normally by the inner ear, may also occasionally result in tinnitus. Prevention involves avoiding loud noise. If there is an underlying cause, treating it may lead to improvements. Otherwise, typically, management involves talk therapy. Sound generators or hearing aids may help some. As of 2013, there were no effective medications. It is common, affecting about 10–15% of people. Most,
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