Sunday, March 1, 2009

Test your audio spectral sensivity

I have created a sound file, which plays all musical notes hearable by the humans. It is the pure tone audiometry file, with that file you can test your hearing capabilities because it has all notes played with the same amplitude, but you will hear them at different levels and some of them will not be heard at all.

Download and play the file (900 KB):
audiometry.mp3

In the following spreadsheet there is each sound described:
list of musical notes

Below is the Matlab code to generate the file above

fs = 44100;
t = 1 : 1/fs : 1.5;
exponents = (-5 + 6/12 ): 1/12 : (5 + 7/12);
frequencies = 440 * 2 .^ exponents;
allNotes = sin(2 * pi * (transp(t) * frequencies));
whole = [];
for index=1:size(allNotes,2)
whole = [ whole transp(allNotes(:,index))];
end
wavwrite(whole, fs, 8, 'audiometry.wav')