MATLAB: What is the x axis and y axis if i plot(y) that y = audioread(​’filename.​wav’)

Question

I have to make equilizer as my project

So i read wav file by audioread

And i have to adjust x axis as frequency and y asix as sound pressure(db is right but it is hard to make to me)

for equilizer project.

But i don't know about axises.

I heared that y axis of plot(y) is sound pressure is it right?

And what is x axis?

help me

Thank you

Answer 1

The output of audioread for floating-point data is normalised to be between -1 and +1. Unless you have additional information about the mapping of the original data to the -1<=y<=+1 you will not be able to recover the original units.

You have to create your own x-axis (actually, time). Do that using Fs (the sampling frequency) as:

t = linspace(0, 1, size(y,1))'/Fs;

Remember that ‘y’ is a (Nx2) matrix (two channels, left channel is ‘y(:,1)’, right channel is ‘y(:,2)’).