2. Importance of root and tuber crops in Africa. In Africa, roots and tubers are generally grown in countries located in the Sub-Saharan zones, notably in Nigeria, Ghana, Cote cÃ´te'D, Ivoire, Nigeria, Benin, Cameroon Central African, Republic.D.R, C, Tanzania, Mozambique, Angola, Uganda, Malawi madagascar And. rwanda
The healthy human ear can hear frequencies ranging from 20Hz to 20,000 Hz. Over time, the hair cellâs hair-like stereocilia may get damaged or broken. If enough of them are damaged, hearing loss results. The high frequency area of the cochlea is often damaged by loud sound.
While 20 to 20,000Hz forms the absolute borders of the human hearing range, our hearing is most sensitive in the 2000 - 5000 Hz frequency range.As far as loudness is concerned, humans can typically hear starting at 0 dB.itch is measured in Hertz (Hz) and loudness is measured in decibels (dB). For a person with normal hearing, when it comes to pitch the human hearing range starts low at about 20 Hz. Thatâs about the same as the lowest pedal on a pipe organ.