What is the name of the tune that contains the frequency of f=494;440;​392;440;49​4;494;494?

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Dear experts, I have a problem to ask.
....we have one-seconded sinusoidal wave with a decaying exponential envelope: t=[0; 1] f(t) = exp(-5t) sin(2*f0t): where fo=[494;440;392;440;494;494;494]; create seven signals with di fferent frequencies and concatenate them into signal array before play sound. By listening to the sound of this sequent wave, what is the name of the tune???...
Actually, I have listen to the sound, but I really can recognize the tune! So, someone help me please!!!
please help me as soon as possible....!!!
  3 Commenti
Davye Mak
Davye Mak il 31 Ott 2014
ok, the code that I wrote is like below:
fs=8e3; t=0:1/fs:1; f0=[494,440,392,440,494,494,494]; a=exp(-5*t); x1=a.*sin(2*pi*f0(1)*t); x2=a.*sin(2*pi*f0(2)*t); x3=a.*sin(2*pi*f0(3)*t); x4=a.*sin(2*pi*f0(4)*t); x5=a.*sin(2*pi*f0(5)*t); x6=a.*sin(2*pi*f0(6)*t); x7=a.*sin(2*pi*f0(7)*t); X=[x1,x2,x3,x4,x5,x6,x7]; sound(X,fs);
that it!!
Matt Tearle
Matt Tearle il 31 Ott 2014
From the frequencies alone you can see that the tune is clearly B-A-G-A-B-B-B... you couldn't figure it out from there? Pfft. I guess that's why you're an image analyst ;)

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Risposte (1)

Star Strider
Star Strider il 30 Ott 2014
Mary Had A Little Lamb!
Reasonable approximation:
fo=[494;440;392;440;494;494;494];
f = @(f0,t) exp(-0.05*t) .* sin(2*pi*f0*t);
t = [0:500]/1000;
s = [];
for k1 = 1:length(fo)
s = [s f(fo(k1),t)];
end
sound(s,1000)
  5 Commenti
Matt Tearle
Matt Tearle il 31 Ott 2014
Not bad, but how about adding a bit of timbre...?
fo=[494;440;392;440;494;494;494];
overtones = [1;0.6;0.5;0.4]; % play with these
f = @(f0,t) exp(-0.05*t) .* sum(bsxfun(@times,overtones,sin(2*pi*f0*bsxfun(@times,(1:length(overtones))',t))));
t = (0:5000)/10000;
s = [];
for k1 = 1:length(fo)
s = [s f(fo(k1),t)];
end
sound(s,10000)
(And the award for Most Pointless MATLAB Code I've Written Today goes to...)

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