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.
The highest frequency that most humans can hear is 20,000 cycles per second or 20,000 Hz. This limit gets lower as humans age. Older people generally donât have as large of a hearing range as younger people. The lowest frequency a human can hear is only 20 Hz, but we can feel sounds lower than that such as for an earthquake. Humans can hear from about 20 - 20,000 Hz, under normal conditions.