How can create a .wav bar based spectrogram on matlab? How can I create a bar based spectrogram that updates as a .wav file is playing. This is commonly found in music players. Here is an example below:


I am able to display a amplitude/frequency graph that updates as the .wav file is being played using this code below:

function syncPlayerDemo()
%some example music
%set up audio player
%player = audioread('test.wav');
[y,Fs] = audioread('test.wav');
player = audioplayer(y, Fs);
[samples,channels]=size(y);
%calculate timeline
t=linspace(0,1/Fs*(samples-1),samples);
%initialize full plot, update will only move the visible area using xlim
h=plot(t,y);
%set up callback to update every &lt;TimerPeriod&gt; s
player.TimerFcn=@timerFcn;
player.TimerPeriod=0.1;
player.playblocking()
end
function timerFcn(source,data)
%an area of length &lt;area&gt; s will be visible
area=1;
position=(source.CurrentSample-1)/source.SampleRate;
%move visible area, current position is in the center
set(gca,'XLim',[position-area/2,position+area/2]);
%used a waitbar for testing, might be commented in
%waitbar(source.CurrentSample/source.TotalSamples);
end


Which results in an updating graph:


How can I get the bars like above, any suggestions?
You can get the bar based spectrogram by decomposing the signal segments into fractional-octave subbands. Try octaveFilterBank and then compute signal power level by pow2db(sum(abs(signal))). This will result in a logarithmic frequency scale.
You can also use pwelch to estimate power spectral density, which brings you a linear frequency scale.