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 chart shows the range of frequencies (from low to high) horizontally and the Sound Pressure Levels (SPL) in Decibels (dB) vertically. The frequency range respresented on this graph is 20Hz to 20,000Hz (20kHz), which is the range of typical human hearing. By looking at this frequency response graph, we can see how capable the speaker is at reproducing the frequencies we can hear.