Musical Instrument Recognition Program help

Question

I am currently working on a LabVIEW program to allow me to
recognize a musical instrument by analyzing its waveform.
I am using LV
7.0 and 7.1. I have 7.0 on my home computer, and the computer labs at college
have 7.1 (both running Windows XP Professional).
I have a few questions. In order for you to understand what
I am talking about, I have included explanations of/(and a link to) my program.
You can go to my website if you want to see more about the
program. It may be helpful to click the “Documents” button and view the "Senior Project Midterm Review Presentation", “Project
Proposal Presentation”, and the "Final Project Proposal".
Website: http://home.pct.edu/~rhijas55/SeniorProject/index.htm
Program: http://home.pct.edu/~rhijas55/SeniorProject/documents/compare.zip
Open the “CompareHarmonics_RM.vi” file, and select WAV files
from the “sound” folder. The recordings in the “sound/no” folder do not match
up correctly. The others do. Make sure that the correct frequency is entered
for the file you are playing.
Questions:
1. What
are some ways that I could more precisely compare two arrays to see how well
they match up?
2.
Should the difference of the waveform’s harmonics be weighted greater when the
harmonics are larger values (earlier harmonics for most instruments), than
the differences of the later (around the 12th harmonic and on)
harmonics which have much lower amplitudes?
3. Do any
of you know of any characteristics that are always found in the waveform of
certain instruments?
4. Does anyone know if there is a way
that LabVIEW can step through the contents of a folder, selecting the next file
each time the loop iterates?
Since the objective of this project is to create a program
that can recognize an instrument based on its waveform, I need to compare
whatever instrument waveform I select, with the harmonics which are
characteristic of different types of instruments.
Message Edited by rhijas on 03-15-2006 08:47 PM

Answer 1

Spreadsheet to Array:
The Bottom section of the Block diagram has many “Spread. to
Array” and “Array Diff.” modules repeating the same thing over and over again.
They take a spreadsheet file from the folder labeled “Harmonic Data Rel. Max”,
convert the file to an array, and find the average difference between each
array value and the coinciding array value of the current waveform. (These
spreadsheet files contain the relative amplitude harmonic values of different
types of instruments.) This average difference and the name of the instrument
are put into arrays. Then the same thing is done with the next spreadsheet file
until all of them have been compared with the current waveform’s harmonics.
Once all the stored files have been compared to the current
waveform, the loop at the bottom of the Block Diagram finds for which
instrument there was the least difference from the current waveform. The idea
is that harmonics of instruments of the same type would have less difference
than two different types of instruments.
What I would like to do is to find a way that I can put all
the converting and comparing into a single loop so I don’t have to duplicate it
for each stored instrument. I would want to look in the folder that holds all
the spreadsheet files, and choose the first file. That file would be converted
to an array, and then compared with the current waveform’s harmonics. The
average difference and the instrument’s name would be put into arrays, and then
the next loop would iterate. For each iteration of the loop, the next
spreadsheet file would be selected from the folder, until all stored files have
been analyzed, and their differences and names put in arrays. Then the arrays
would be sent to the last section where it would determine which stored
harmonic array hast the least difference from the current waveform’s harmonics.
Does anyone know if there is a way
that LabVIEW can step through the contents of a folder, selecting the next file
each time the loop iterates? That would make it a lot easier to add more
stored harmonic files so I won’t have to repeat the code for each file added to
the folder.
I should also be able to more successfully recognize
instruments if I have more samples of instruments stored to account for
variations among instruments.