frequencies

[samba - <sambacomet@hotmail.com>]

 I read a piece in either  recording engineer ,or mix  the early to mid 90s,(it was sort of in between the late early 90s,n the early mid 90s.) Some japanese engineers rather than doing a/b tests and asking people if they could id which was analog and which digital,instead measured brainwave responses,and found that after 20 minutes or so analog elicited some sort of measurable entrainment between brain halves,which the digital did not trigger.
  It is possible that freq above what can be percieved as audio still effect bodies in some way. I think it's a common assumption that the ears are all that is effected by sound.which is certainly not true. If it was this subwoofer fad wouldn;t be happening. In the old days when people communicated across distances with drums,it slikely that the sound could be felt throgh the ground. Modern life is so full of noise that folks screen out as much or more than they let in.
 Perhaps the overtone series above human audio range effects lower freq in percievable ways. Human a range upper end is usually considered 20khz,contrast some birds that can hear 200,000 hz.