psychoacoustics

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steevio
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Re: psychoacoustics

Post by steevio » Thu Apr 26, 2012 3:34 pm

well now i'm as confused as you hairblz mate,

because i did an experiment with two triangle waves and the interference did indeed produce the 'phantom wave' on the oscilloscope, although it was only very low amplitude and unlikely to be audible, so you are right the tone isnt psychoacoustic really because the wave does exist, maybe the brain just amplifies it's significance ???

i dunno i've been reading about these effects for years and assumed the tone was entirely created in the brain.

but there again i havent tried to create the missing fundamental by this method, i dont have enough VCOs in my rig.
over to the software guys for that.

hairblz
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Re: psychoacoustics

Post by hairblz » Thu Apr 26, 2012 8:01 pm

You should try with ableton or something! Not only will you get more oscillators, surely their phase and timing will be much more reliable than using analog gear . . .

I just did this stuff in college, I (personally) came to the conclusion that the "missing fundamental" effect was created by the brain being accustomed to hearing many harmonics, and so if one was missing, the brain would fill in the blanks and make a guess, just like the haas effect, or blind spots in vision, illusions.

But aye, if the (subjective) waves were purely psychoacoustic, it's a bit hard to see how they would muddy up your mix . . .

"Waves" make a plugin that can increase the amount of perceived bass by adding higher harmonics, so that your track can still sound bassy from laptop speakers. But whether these perceived bass notes can actually interfere with *real* bass tones, I'm not so sure . . .

It would be interesting to experiment using phase inversion . . . I don't have the plugin though, and I can't seem to hear missing fundamentals anyway
Last edited by hairblz on Thu Apr 26, 2012 8:44 pm, edited 1 time in total.

mehta
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Re: psychoacoustics

Post by mehta » Thu Apr 26, 2012 8:21 pm

Very interesting topic, but the responses have been pretty confusing so far.

"Missing fundamentals" are a psychoacoustic effect and have nothing to do with differential tones as far as I know ...

hairblz
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Re: psychoacoustics

Post by hairblz » Thu Apr 26, 2012 8:43 pm

mehta wrote: "Missing fundamentals" are a psychoacoustic effect and have nothing to do with differential tones as far as I know ...
I believe they are very closely related. I agree that they're a psychoacoustic effect.
Last edited by hairblz on Thu Apr 26, 2012 8:46 pm, edited 1 time in total.

steevio
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Re: psychoacoustics

Post by steevio » Thu Apr 26, 2012 8:44 pm

hairblz wrote: But whether these perceived bass notes can actually interfere with *real* bass tones, I'm not so sure . . .
why not ?

they can certainly have a masking effect, if you perceive it you perceive it, simple.

hairblz
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Re: psychoacoustics

Post by hairblz » Thu Apr 26, 2012 8:52 pm

steevio wrote:
hairblz wrote: But whether these perceived bass notes can actually interfere with *real* bass tones, I'm not so sure . . .
why not ?
It's just my hypothesis, let me explain.

Take a bunch of sine harmonics playing together that produce a missing fundamental of 300Hz, so your brain is perceiving 300Hz.

Now, while this playing, get a 300Hz sine wave with inverted phase, and play it at the same time.

This will either cancel out the perceived 300Hz or not. If they were both regular sine waves, the result would be silence. I'm not fully convinced either way, but I speculate that a psychoacoustic 300Hz tone is not powerful enough to cancel out a real one.
steevio wrote: they can certainly have a masking effect, if you perceive it you perceive it, simple.
Right enough.

oblioblioblio
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Re: psychoacoustics

Post by oblioblioblio » Thu Apr 26, 2012 9:04 pm

i studied psychology at uni and I thought it was the dumbest thing I ever heard (well, a lot of it anyway).

The mind, spirit and emotions are intimately connected in an unbeliveably complicated system. I have very little faith in being able to study the mind by isolating one part of it and looking at it under a microscope. You cannot look at human behaviour in a darkened laboratory studying a specific response without considering the whole or removing the impact of the laboratory on the behaviour.

I don't want to knock this thread, becuase of course there is a lot of truth in it ( for example it's really interesting that some people hear undertones and some hear overtones). , but I wanted to reinforce my belief that this is only 1 very small part of an infinitely complex picture. Who knows what someone feels when they hear a whole piece of music, maybe they see light from it. Maybe they see themselves clearly.

Besides, my music nowadays seems to all come from heavy frequency modulation and amplitude modulation so I have so much sideband oscillations that I can't possible keep track of another set. heheh.

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