Quantifying What You Hear...

[Dave McKibben]

Sounds like a very interesting piece for work your getting into.
It makes me wonder if there would be a correlation between  the magnitude
of harmonics / partials of a fundamental tone to the terms we use as
bright, muddy, sharp etc.
If it could be possible to look at a spectrum and define its shape as
bright versus muddy, then it seems that voicing could take a step from
seeming mysterious to more of a definable process.

Just thinking out loud ( I could be waaaayyyyy off ).

Dave M.

> [Original Message]
> From: Matt Borland <mattborland at gmail.com>
> To: <pianotech at ptg.org>
> Date: 12/29/2006 4:37:07 PM
> Subject: Quantifying What You Hear...
>
> Hello,
>
> I'm new to this list, but I was wondering if I could get some 
> help/opinions/ideas about the way sound in musical instruments is 
> described. Currently I'm doing a masters working with Stephen Birkett 
> at the University of Waterloo and one of the big problems we have found 
> is the inability to discuss musical acoustics in any quantifiable way 
> that has meaning to both musicians and people using a scientific 
> approach (not to say that people can't fall into both of those groups 
> at the same time). My work is going to involve piano soundboards, but 
> before I start on that I want to think about and define some ways to 
> describe the sound/tone of the soundboards and pianos I will be 
> measuring for vibrational and acoustic properties.  I think we've all 
> used words like bright, muddy, crisp, sharp, round, dark, etc. to 
> describe the sound of an instrument, but these are highly subjective 
> words that are difficult to draw any concrete conclusions from. So the 
> question is, are there any other parameters you feel would be useful to 
> quantify? Maybe there is a way to measure how "bright" something 
> sounds...If you have a concept and some sort of definition to go along 
> with it I'd love to hear from you.
>
> Some obvious ones (if these are poorly defined, feel free to redefine 
> them) are:
>
> decay time - the time it takes for sound level to decay by a defined 
> amount (ie 60dB, or whatever, I'm thinking of the RT60 definition for 
> reverberation time from acoustics) linked to sustain
> impedance - a measure of opposition to motion of a structure subjected 
> to a force
> bloom - change in tone over time
> response time - is the time a system or functional unit takes to react 
> to a given input
>
> Basically I would like to make the link between the frequency and modal 
> analysis techniques available with the language that musical 
> instruments are discussed in terms of. I really doubt anyone has talked 
> about how nice the mode shapes of their pianos are, but maybe if things 
> like this are connected to the way they sound by some common definition 
> or understanding then they could be used to measure the properties of 
> an instrument. I would also like to make the link between these 
> techniques and the way we perceive sound and pitch, something that I 
> feel has been forgotten in a lot of research work.
>
> Any help or ideas would be greatly appreciated,
>
> Matt Borland
>
>