what does blue colour in frequency representation of audio signal indicates?

i have audio signal which is baby's cry signal. it is plotted in frequency domain. signal is shown in green colour but some part in it is blue. what is that blue colour signal? below is image shown. pls help

Answer 1

[Salaheddin Hosseinzadeh]

You are plotting a stereo signal with 2 channels.

One channel is in green and one is in blue.

Plot them in separate figures

probably your data has the dimension of Nx2

figure
plot(data(:,1));
figure
plot(data(:,2));

[pranjal]

thank you sir. but my .wav file is Nx1.

[Salaheddin Hosseinzadeh]

MATLAB plot does not discriminate the graph automatically, unless you pass it a matrix. The colors will be different for every column!

You data may have 1 column, but I guess what ever you do to it, you are turning it into a matrix before the plot, or you are passing two set of variables to the plot command

plot(x,y,z,t)