See: SOUND, SPEED OF SOUND. Compare: ACOUSTIC RADIATION ... 25 dB/100 m for 30% relative humidity and 20°C (68°F). It should be noted, however, it can be as high as 5 dB/100 m at 8 kHz when the ...

According to the United States Air Force website, the speed of sound is roughly 750 miles per hour (1,207 kilometers per hour) at sea level. This varies with factors like temperature and humidity.