missing fundamental

[Robert Adams]

The ear has a characteristic that if you apply a series of
harmonically-
related tones but leave out the fundamental, the brain will fill it
in
for you; in other words, if you mix 50Hz, 75Hz, and 100Hz together
you
will perceive the missing fundamental at 25 Hz. Many bass-enhancement
algorithms use this trick (although one has to question what happens
in the case where the bass energy is not single-frequency!).


What I would like to know is how far up in frequency this effect
occurs. It seems as if the ear transitions from waveform mode at low
frequencies to envelope mode at higher frequencies, so it seems
doubtful that the missing fundamental effect still occurs at higher
frequencies. For example, if I mix 2Hz, 3KHz and 4 KHz do I hear 1
KHz?


Thanks for any replies!


Bob Adams

[Ethan Winer]

if I mix 2Hz, 3KHz and 4 KHz do I hear 1 KHz?

Why don't you just try it yourself? :->)

I just did that and I hear it as 2 KHz, not 1 KHz. I did the same
thing at 200, 300, and 400 and I heard 200 Hz, not 100.

Go figure.

--Ethan

[Jens Rodrigo]

Post by Ethan Winer

if I mix 2Hz, 3KHz and 4 KHz do I hear 1 KHz?

Why don't you just try it yourself? :->)
I just did that and I hear it as 2 KHz, not 1 KHz. I did the same
thing at 200, 300, and 400 and I heard 200 Hz, not 100.

Read here:
http://en.wikipedia.org/wiki/Missing_fundamental
General population can be divided into those who perceive
missing fundamentals, and those who primarily hear overtones.
Ethan belongs to the overtone listeners.

Regards Jens

PS: http://dbpedia.org/page/Missing_fundamental

[Ethan Winer]

Post by Jens Rodrigo
General population can be divided into those who perceive
missing fundamentals, and those who primarily hear overtones.
Ethan belongs to the overtone listeners.

Interesting. However, I do hear electric guitar and bass note pitches
properly, even though the fundamental is typically 12 dB or even lower
than the second harmonic. Of course, that's not the same as the
fundamental being missing entirely. But even adding severe thinning
with a high-pass filter I still hear the correct fundamental. I tried
this about a year ago, taking the thin tone my Telecaster's treble
pickup and making it even thinner with a few stages of filtering. I'll
have to try this again some time using even steeper filters.

BTW, when I mixed the three tones yesterday as a test I made them all
the same level. Perhaps if I spent more time experimenting with the
relation between the levels I could have heard the missing
fundamental.

--Ethan

[Salmon Egg]

In article

Post by Ethan Winer

if I mix 2Hz, 3KHz and 4 KHz do I hear 1 KHz?

Why don't you just try it yourself? :->)
I just did that and I hear it as 2 KHz, not 1 KHz. I did the same
thing at 200, 300, and 400 and I heard 200 Hz, not 100.
Go figure.
--Ethan

You have to specify exactly what you mean by mixing. If you just send an
electrical signal to a good speaker, no new tones will be generated, You
need a nonlinear device to create difference frequencies. Often, that
device is an ear.

Bill

[answerman]

Post by Salmon Egg
In article

Post by Ethan Winer

if I mix 2Hz, 3KHz and 4 KHz do I hear 1 KHz?

Why don't you just try it yourself? :->)
I just did that and I hear it as 2 KHz, not 1 KHz. I did the same
thing at 200, 300, and 400 and I heard 200 Hz, not 100.
Go figure.
--Ethan

You have to specify exactly what you mean by mixing. If you just send an
electrical signal to a good speaker, no new tones will be generated, You
need a nonlinear device to create difference frequencies. Often, that
device is an ear.
Bill

He means add/sum the tones linearly, which is both obvious and implicit
in his reference to the psychoacoustic phenomenonon involving the
perception of a so-called missing fundamental.

Since he didn't bother to thank me for answering the last question that
he posted here, I'll let him look up the answer to this one himself.

[Salmon Egg]

Post by answerman
He means add/sum the tones linearly, which is both obvious and implicit
in his reference to the psychoacoustic phenomenonon involving the
perception of a so-called missing fundamental.
Since he didn't bother to thank me for answering the last question that
he posted here, I'll let him look up the answer to this one himself.

Such a process is not mixing from my electrical background. No new tones
will be detected with a linear spectrum analyzer. Beats are not new
tones. The ear and all its physical and neural capabilities is beyond my
understanding at this time.

Bill

[answerman]

Post by Salmon Egg

Post by answerman
He means add/sum the tones linearly, which is both obvious and implicit
in his reference to the psychoacoustic phenomenonon involving the
perception of a so-called missing fundamental.
Since he didn't bother to thank me for answering the last question that
he posted here, I'll let him look up the answer to this one himself.

Such a process is not mixing from my electrical background.

If so, then your electrical background is extremely limited. To an RF
engineer, mixing involves a nonliear process whose sole purpose is to
generate distortion products. To an audio engineer, mixing involves the
linear summation of different signals. Ever heard of an audio mixer or a
studio mixing console?

Post by Salmon Egg
No new tones will be detected with a linear spectrum analyzer.

So what? The ear is not a linear spectrum analyzer.

Post by Salmon Egg
Beats are not new tones.

Who said anything about beats?

Post by Salmon Egg
The ear and all its physical and neural capabilities is beyond my
understanding at this time.

It's beyond my understanding too, but that's not the issue. The question
was "what" happens not "why" does it happen.