Subject: Why do low frequency waves seem to travel farther than high frequency waves

   Situation: I hear a fog horn across a lake, and it seems like the lower 
frequencies are either louder or travel farther.  What property of the 
lower frequency waves causes this phenomenon?  
   This also seems to happen when overhearing a radio that a neighbor may 
be playing outside.  The lower frequencies are audible, but the higher 
frequencies are not as audible.  If they are both coming out of the same 
radio with the same volume level, shouldn't they both be equally audible?

Re: Why do low frequency waves seem to travel farther than high frequency waves