Working donkeys are often associated with those living at or below subsistence levels. Small numbers of donkeys are kept for breeding or as pets in developed countries. A male donkey or ass is called a jack, a female a jenny or jennet; a young donkey is a foal.Jack donkeys are often used to mate with female horses to produce mules.he donkey has been used as a working animal for at least 5000 years. Of the more than 40 million donkeys in the world, about 96% are in underdeveloped countries, where they are used principally as pack animals or for draught work in transport or agriculture.
In simplistic language, every matter in this world vibrates, so that vibration we call frequency, and we measure it in Hz. The sound has its own frequency which is also measurable in Hz. The guy in the beginning of the video says that everything owes its existence to sound.
High frequency sounds are usually shrill like a whistle whereas low frequency sounds are more like the deep hum of an amplified bass instrument. The highest frequency that most humans can hear is 20,000 cycles per second or 20,000 Hz. This limit gets lower as humans age. Older people generally donât have as large of a hearing range as younger people.