Redefining Dementia as a Terminal Illness. Dementia is most often thought of as a memory disorder, an illness of the aging mind. In its initial stages, that's true â memory loss is an early hallmark of dementia. But experts in the field say dementia is more accurately defined as fatal brain failure: a terminal disease, like cancer, that physically kills patients, not simply a mental ailment that accompanies older age.
Frequency is measured in the number of sound vibrations in one second. A healthy ear can hear sounds of very low frequency, 20 Hertz (or 20 cycles per second), to a very high frequency of 20,000 Hertz. The lowest A key on the piano is 27 Hertz. The middle C key on a piano creates a 262 Hertz tone. The highest key on the piano is 4186 Hertz.
Frequency. Frequency is a measurement of how often a recurring event such as a wave occurs in a measured amount of time. One completion of the repeating pattern is called a cycle. Only moving waves which vary their positions with respect to time possess frequency. Frequency is one way to define how fast a wave moves.