On Sun, 11 Jan 2004 14:09:58 GMT, "Allen L. Barker"
<alb at datafilter.com> wrote:
} Doktor DynaSoar wrote:
} > On 9 Jan 2004 14:13:56 -0800, curious11112001 at yahoo.com (Curious)
} > wrote:
} > } Invented by Patrick Flanagan. It is said to directly stimulate parts
} > } of the brain's auditory cortex to produce sound perception. Is this
} > } too good to be true?
} > }
} > } Thanks in advance.
} > It definitely doesn't stimulate the auditory cortex to create sound
} > perception. It modulates sound into an FM radio signal. The auditory
} > cortex does not process sound, whether modulated into another
} > frequency or not. It processes neural impulses.
} It can modulate the sound of an FM radio *onto* its ultrasonic signal,
} but it does not modulate the sound *into* an FM radio signal. And
} apparently the ultrasonic signal is amplitude modulated rather than
} frequency modulated.
} See my earlier article in the thread and the links there for much more
I have. I originally read the design in Flanagan's book, 30 years ago.
The 50 kHz signal generator is for setting the spacings in the
constant amplitude square wave. It's more akin to sampling while
ignoring the amplitude of the original signal. Saying it is
"ultrasonic" is as incorrect as applying that word to a 44.1 kHz