Why Are Diesel Generators Usually So Noisy? Where Does the Noise Come From?
The human hearing range spans from 20 Hz to 20,000 Hz. Frequencies below this range are called infrasound (frequencies elephants can hear), while higher frequencies are called ultrasound (frequencies bats can hear). High frequencies are particularly intense for the human ear: the most sensitive range for human hearing is between 2,000 Hz and 4,000 Hz.[…]