Eggs that you buy from the store will not stay fresh for long  without refrigeration. Eggs that come right from the chicken can  kept at room temperature for weeks. Store bo â¦ ught eggs should be  refrigerated within a few hours of buying them just to be safe.ven with its natural (but easily cracked) calcium-carbonate container, a hard-cooked egg is a perishabl â¦ e food, so it shouldn't be kept at room temperature for more than two hours.   If kept in an unbroken shell and in the refrigerator about a week.
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.
High frequency sounds are usually shrill like a whistle whereas low frequency sounds are more like the deep hum of an amplified bass instrument. 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.