May I ask how to get the value of amplitude from one wav. file?

May I ask how to get the value of amplitude from one wav. file? Because I want to do distortion wav. file..

Answer 1

[Image Analyst]

The amplitude is the value of the array at that element. If you want the max value over all elements, use max().

[y,Fs] = audioread('guitartune.wav'); % y can have + and - amplitudes.
amplitudes = abs(y);  % abs(y) is the amplitudes in an all-positive sense
maxY = max(abs(y)); % maxY is the highest amplitude.

[loong seow li]

thank you... it is work...but why will come out two values when I test other wav file?

[Kevin]

You get 2 values because y is a matrix of 2 columns and that is because your wav file has 2 channels (left and right channels).

[loong seow li]

So is that possible I change the two amplitude value and save it as new wav file?

[Image Analyst]

Yes, of course.

[loong seow li]

For example, the I get maxY= 0.8000 from my wav file... how to convert to wav file by change the maxY=0.100?

[Image Analyst]

You can simply use multiplication and division to scale your vector or matrix to anything you want.

desiredMax = 0.1;
yScaled = y * desiredMax / maxY;

[loong seow li]

okok....thanks a lot