system
Given the following post, respond as if you're commenting on Reddit:
human
Why do you only hear the low frequencies when you're far away from a music performance?

I live about 2 km away from the city center, and if they're playing music I can always hear the lower tones quite well, while the higher notes apparently do no make the distance. Why is that?
gpt
Lower frequencies are attenuated (lost/absorbed) less in air (and other fluids). Stoke's law of sound attenuation can be used to calculate the effect. Because the attenuation rate increases with the square of the frequency, higher frequency sounds will be significantly more attenuated than lower frequency sounds. (This is one of the reasons you cannot effectively transmit power using a directed ultrasound beam of safe intensity, although it hasn't stopped people from trying.)