cant get an accurate fft of live audio signal

hello I want to get a live fft of my live audio signal. this my code , how ever my fft is wrong . could some one explain my why ?

clc;
clear all;
close all;

recorder = audiorecorder(96000, 24, 1);
disp('Start speaking.')
recorder.record(5);

while recorder.isrecording()
        pause(0.1);
        subplot(2,1,1);
        plot(recorder.getaudiodata());
        title('live recording of sound(t)')

         y=getaudiodata(recorder);
          fft_getaudio=fft(y,length(y));
          subplot(2,1,2);
           plot(linspace(0,5,length(y)),fft_getaudio);
           title('live recording of  fft (sound(t))')

      drawnow();
  end
  disp('End of Recording.');

[Aquatris]

Check the documentation of fft function and modify their example. There are a lot of things that are wrong in your implementation.

[tomer polsky]

I read the fft help and tried what is written and I wote this code :

     y=getaudiodata(recorder);
          fft_getaudio=fft(recorder.getaudiodata());
          n=1:length(fft_getaudio);
          subplot(2,1,2);
           plot((fft_getaudio),2.^nextpow2(n));
           title('live recording of  fft (sound(t))')

how ever I still get wrong plot of the fft ,any ideas ?