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 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.Sensitivity also varies with frequency, as shown by equal-loudness contours.heir hearing range varies by species; at the lowest it can be 1 kHz for some species and for other species the highest reaches up to 200 kHz. Bats that can detect 200 kHz cannot hear very well below 10 kHz. In any case, the most sensitive range of bat hearing is narrower: about 15 kHz to 90 kHz.