Re: How come when you're far away from sound you only hear the low tones?

Hi,

This phenomenon is quite simply due to the fact that air absorbs high 
frequencies more heavily than low frequencies. Since the viscosity of air 
is finite, a rapid pressure change will cause more friction loss in air 
than a slow pressure change. As you move further away from the sound 
source, more and more high frequencies get absorbed compared to the low 
frequencies.
This property is strongly temperature and humidity dependent. Some figures 
are given here: http://www.sfu.ca/sonic-studio/Sound_Propagation.html

Regards,

Bruno