Che wrote:
quoted 4 lines i am not versed in the science of sound, but can> >i am not versed in the science of sound, but can
> >humans hear over 20 khz?
>
> I can. Ultrasonic sensors drive me nuts.
me too...but neither you nor i can actually hear them...what we do hear is the
effect of the ultrasonic sensors heterodyning the air and creating harmonics
below the actual tone...i.e. a 30khz tone might give off some low volume 15khz
harmonics, which you can hear if you have good ears...to see if you can
actually hear 20+ k tones, you really need to listen to them on good
headphones in one of those listening test type environments...(i.e. you can't
see when someone is or isn't playing a tone)