Origins of the Domino Theory. In September 1945, the Vietnamese nationalist leader Ho Chi Minh proclaimed Vietnamâs independence from France, beginning a war that pitted Hoâs communist-led Viet Minh regime in Hanoi (North Vietnam) against a French-backed regime in Saigon (South Vietnam).
The human range is commonly given as 20 to 20,000 Hz, though there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies with age is considered normal.
The Science of Hearing. The human hearing range is between 20 to 20,000 Hz. There is considerable variation. in the hearing range between individuals. Most young people can hear up to 18,000. Hz. Our ability to hear high frequencies declines with age. By the age of 55 some men. can't hear above 5,000 Hz and some women canât hear above 12,000 Hz. Women tend. to have better hearing than men at high frequencies.