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.
However, this results in extremely high frequencies, far higher than those that any known species can perceive (some bats can hear frequencies as high as about 250,000 Hz). Rodents can generally hear higher frequencies than humans. It's difficult to give an average frequency for the hearing ability of rats, but it would be much higher than for people. The hearing range for rats is about 200-75,000 Hz. Beyond that, I can't really answer your question, as I'm not really sure what you are requesting; hopefully this helps somewhat!