[Tftb-help] problem with measuring the .wav file (audio file)

[Wee H. Tey]

Hello,i'm a Msc student who studing at Sheffield Hallam University. 
i'm now having a final project to measure audio files with different bit rate.
i'm interesting in using tftb to measure it.
However, i'm facing a problem that is i can't get the result i want. it is
shown in 
attached file.
Is it problem with the frequency scale or the number of frequency bins?
Beside that, am i using the wrong time frequency distribution. 
 
the below is the code i write it into tfdemo1. 
[x,fs]=wavread('Tomsdinermn.wav');
N=length(x);
t=1:32:N;
Nf=1024;
f=(0:Nf/2)/Nf;
h=hanning(257);
tfrsp(x,t,Nf,h);

Thank you in advance and hope can reply me soon.

1.fig
Description: Binary data

Image2.gif
Description: GIF image