Actual spoken language of man developed only approximately 200,000 to 100,000 years ago. As a result of natural selection, man has developed hearing, which is most sensitive in the frequency regions of 200 to 4000 Hz, corresponding to those of spoken sounds. Functional hearing has been one of the prerequisites for the development of speech, although according to current opinion the language itself may have evolved by mimicking gestures with the so-called mirror neurons. Due to hearing, gesticulation was no longer necessary, and the hands became available for other purposes.