United States: early hominid ears were tuned to the speech
The structure of the ear needed for speech perception of each other, appeared at the earliest hominids no later than 350,000 years ago. This may mean that a rudimentary form of speech appeared very early in the course of human evolution. This conclusion was based on the study of fossilized skulls found in the mountains of Spain. Group Spanish and U.S. scientists using computed tomography and bone cavities of the outer and middle ear with five samples, which is believed to belong to the species Homo heidelbergensis. This species was one of the ancestors of Neanderthals.
Scientists have tried to determine how well the hearing aid can perceive sounds of different frequencies. It turned out that the ears of hominids is best perceived sound frequency 4.2 kHz, that is in the range of the most important for the perception of human speech. For comparison, ears chimpanzees relatively insensitive to these frequencies. Their ears are tuned to sound perception about one and about eight kilohertz.
Modern people listening in the range of 2-4 kHz is also escalate. Moreover, the sensitivity of the ears of these hominids apparently approached the sensitivity of the ears of modern man, which may mean that they, too, were able to perceive it.
News.Battery.Ru — Accumulator News, 24.06.2004 15:47