You may have wondered how we came up with the recommendation that women have 500 calories and men have 600 calories on a Fast Day. We used the rule of thumb that women need 2000 calories and men need 2400 calories per day and on a Fast Day you should eat a quarter of a normal dayâs recommended calories. Some of you have also wondered exactly how many calories you should be eating on days when youâre not fasting.
According to most sources, the human hearing (frequency) range is between 20 Hz and 20,000 Hz (bats can hear up to 100,000 Hz!). What does that mean? Sound is a mechanical wave that propagates through a medium (air, water), and the frequency of a sound wave determines its tone and pitch.
Is the frequency of sound measured in units called decibels?  The frequency of sound is measured in Hertz named after   Heinrich Rudolf Hertz, the first person to measure  electromagnetic waves. A single Hertz represents a single â¦cycle per  second. Humans can hear sound from about 40 hertz to nearly 15000  Hertz (also called 15 kilohertz, abbreviated as 15 Khz). Some  people with exceptional hearing range may go up to 20 Khz. Some  animals can hear even higher frequencies.     Decibels are a measurement of how loud a sound is.