[Harp-L] Comb Materials: the Perfect Test Harmonica?

[Sheltraw]

I agree with Vern. What the ear and brain "hears" is not only what is in the spectrum of the sound as measured by a frequency analyzer (or wavelet analyzer, etc). Even within the first stages of the human auditory system there exist nonlinear effects that result in sum and difference frequencies of the frequencies that would be measured by an spectrum analyzer.

To wit one can construct a speaker and voltage source that would generate a very narrow spectrum centered about a single frequency. If one presents that sound to a human they don't hear just a single frequency because of the previously mentioned nonlinear effects occurring in the ear. Within the auditory cortex things may be even more complicated. 

So you might find some significant differences between different combs as measured by an analyzer but whether they are significant after the ear "filter" acts upon the sound and "signal" is a whole nother thang. 

At this point in our understanding of the human auditory system the subjective experience will be far better at assessing the differences in sound produced by comb materials than any quantitative measurement.

Cheers,
Daniel

Sent from my iPhone

> On May 12, 2016, at 9:53 PM, Vern <jevern at fea.net> wrote:
> 
> A sound analyzer would not help you to find the elusive materials effect.  It might reveal small differences which undoubtedly exist at some level.  It would not tell us if humans can perceive them.  For that you need humans trying to do so under controlled conditions.  The day is imperceptibly brighter when the quarter moon is in the sky.  The sound is imperceptibly louder when there is a fly buzzing near the moving train.  It is only in the Hans Christian Anderson fairy tale that the princess can feel the pea under her mattress.
> 
> If you seriously want an analyzer, there are inexpensive apps that will print out the spectrum of an audio file using the FFT (fast fourier transform.)  
> http://www.nch.com.au/wavepad/fft.html <http://www.nch.com.au/wavepad/fft.html>
> 
> Vern
> 
>> On May 12, 2016, at 6:17 PM, Joseph Leone <3n037 at comcast.net> wrote:
>> 
>> 
>> Eye.........whant.......a.......sownd.......analyzer. And until I get one, I am going to hold my breath till I turn blue.
>> 
>> JoeL (aka Mr. Bleau)
>