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.
Loudness or amplitude is measured in decibels and it is marked or notated using dB to designate decibels. Keeping in mind that at 85 dB hearing loss can begin, normal everyday conversation is at approximately 70 dB and loud talking is about 90 dB.This is one of the reasons why loud and boisterous people bother us so much.oudness or Amplitude â Science, specifically audiology, knows that the difference between the threshold of human hearing (0 dB) and the threshold of pain (120 dB) and hearing loss occurs at approximately 120 decibels.