Measure the temperature via the sound of crickets

To measure the air temperature, usually people will use a thermometer. If you live in the countryside or a quiet place, trying to do with listening to the crickets.Sound of crickets from the friction created between the wings with some other body parts. Their voices were very distinctive, and clearly heard in an environment which is not too noisy.
Not all crickets can skirl, only male crickets can do that. The voice is like a melodious song, which is sung to attract female crickets.
In addition to good to be heard, rhythmic sound of the crickets are apparently also be used to estimate the temperature outdoors. The more often the sound of crickets is heard, the more heat the ambient temperature at the time.

Quoted from Snopes, Wednesday (07/21/2010), experiments to prove this had started in 1897 by the American physicist, Amos Dolbear. His theory of the thermometer crickets became known as Dolbear's Law.
Many years since the discovery, a formula about the relationship to the crickets and the temperature continues to grow. But among the various existing formulas, the most frequently used are as follows :

To estimate the ambient temperature in Fahrenheit, count the number of sounds of crickets in 14 seconds then add 40. (T = n + 40) ie 30 times the crickets + 40 = 70 degrees Fahrenheit

To estimate the ambient temperature in Fahrenheit, count the number of the sound of crickets in 25 seconds, divided by three, then added 4. (T = (n / 3) + 4) examples: (48 times the sound of crickets / 3) + 4 = 20 degrees Celsius  

Above formula proved by Dr. Peggy LeMone, scientists The Globe Program in experiments in 2007, funded by NASA. In his report he concluded that the formula is very close to actual temperature, measured with a thermometer.
But Dr Peggy gave a note, this formula should be used at temperatures above 55 degrees Fahrenheit (12.78 degrees Celsius). Because if it is too cold, usually male crickets are not eager to call the female.