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.
What is the normal respiratory frequency? Medical textbooks suggest that the normal respiratory rate for adults is only 12 breaths per minute at rest. Older textbooks often provide even smaller values (e.g., 8-10 breaths per minute). Most modern adults breathe much faster (about 15-20 breaths per minute) than their normal breathing frequency.