Find energy for each second of audio file

Hi,

I have an audio signal which has 44.1 KHz sampling rate, which would be stored as an array. I am trying to find energy for each second using:

sum(x.^2);

Can someone help me how to do that? Thanks

Answer 1

[Star Strider]

Use the buffer function:

Fs = 44.1E+3;                               % Sampling Frequency
s = randn(Fs*5.2,1);                        % Signal
seconds_sampled = 1;                        % Desired Smaple Length
sec1 = Fs*seconds_sampled;                  % Corresponding Samples
s_sections = buffer(s,sec1)

s_sections = 44100×6

1.5751 1.0628 0.3946 0.6711 -0.3298 -2.0274 1.5076 1.0714 0.6997 -1.6182 -0.7092 0.3166 -0.9737 0.2084 0.1273 -0.9344 0.6038 -0.0711 0.2128 0.7510 0.3992 -0.5763 -0.0085 -0.7977 -0.8026 1.5172 -0.1044 0.7109 0.4487 1.7293 0.1842 -0.8955 0.0778 -0.2759 -0.5885 1.3357 -0.7606 0.9031 -0.5579 -0.3093 -1.3640 0.1967 0.1805 1.6719 -0.8658 1.0763 0.9120 0.9080 0.0411 -0.1559 -0.9230 -1.8707 -0.3266 -1.5487 -1.1568 0.2762 0.5586 -0.8734 0.1023 1.6655

Check = size(s_sections)

Check = 1×2

44100 6

Energy = sum(s_sections.^2)

Energy = 1×6

1.0e+04 * 4.4284 4.3893 4.4579 4.4808 4.4129 0.9051

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[Giggs B.]

Okay got it, Thanks, just one doubt...this "1.0e+04" is multiplied with all the elements in energy vector (displayed values) right ?

[Star Strider]

Yes.

It is the common multiplier of all the elements in the ‘Energy’ vector.

.

[Giggs B.]

Got it, Thank you!

[Star Strider]

As always, my pleasure!

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