Hi:

I notice when I listen to heterodynes on the AM radio, I get a feeling
of both fear and enjoyment. I find the heterodyne to give me a very
strange emotional feeling that I can't describe. When I was a kid, I
used to play NES [Nintendo Entertainment System] on my TV. The NES
required channel 3 to be used. I would use channel 4. On channel 4, the
image of the video game was there [albeit hazy and B&W], the music of
the game was not there. Instead I heard the strange sounds [resembling
heterodynes] and -- to a much smaller extent -- the audio the was on
whatever was being shown on channel 4 [e.g. NBC news].

When I was in the second half of my 1st-grade, the schoolbus I was in
used to have a CB radio. Whenever someone on the other end said
anything on the CB radio, the reception was accompanied by the sounds
resembling heterodynes. I would get so scared when I heard them. I
don't know why I get so emotional when I hear those sounds.

I am curious as to whether I am the only one who feels this way when
listening to heterodynes and similar sounds.

Perhaps there is an unconscious association with heterodynes and
emergencies, since most police, firefighters, and other emergency
services often communicate with radios which often experience
heterodynes. The heterodyne maybe high or low pitched but either way it
gives me the same scary yet enjoyable feeling.

Maybe its those binaural beats in the brain resulting from heterodyning
within the central nervous system :-)

http://www.answers.com/heterodyne&r=67

Heterodyning in the human brain

"Heterodyning is not confined to electrical signals, but can occur in
any medium where signals of different frequencies are mixed, such as
sound vibrations in the aircraft engine example given above. The human
brain heterodynes stereo signals; by playing two tones with different
frequencies (or the same audio with different phases), a beat frequency
called a binaural beat is produced inside the brain."

"Some people claim that this phenomenon can be used to alter their
brain wave frequencies. As the human ear cannot detect the low
frequencies required for this phenomenon, a pair of higher frequency
tones must be used. The brain wave frequencies range from 1 to 30 Hz or
so, while the ear is sensitive to no signal lower than 20 Hz. (For
example, a 102 Hz signal mixed with a 100 Hz signal will produce a beat
frequency of 2 Hz, the difference of the two; but its tone will sound
like 101 Hz, the average of the two. One would hear a 101 Hz tone with
an amplitude (or volume) which oscillates twice per second. While a 2
Hz non-heterodyne signal could be produced, it would be impossible to
hear.) Optical stimulation is usually more successful, as much more of
the human brain is devoted to processing visual information, and it can
utilize amplitude modulation, rather than beat frequency. Stimulation
in this manner can produce changes in consciousness, as different brain
wave frequencies are associated with unique states of mind. Epileptics
and people otherwise sensitive to flashing lights should use caution
with any brain wave stimulation technique."


Regards,

Radium