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.
Hearing range in humans is commonly between 20 and 20,000Hz. As we get older, this range gradually declines and teenagers can typically hear higher frequencies. Vowel sounds are typically low frequency, while consonants are higher. This audiogram shows a sine wave going through human audio spectrum.