Signal Processing with wavelet transform

Hello everyone.I'm on signal proccessing and i have a folder with audio files (file ext. .wav).I want to do theese audio files some transforms,create their pictures andkeep them image folders.After creating this pictures ,my purpose is , train artificial neural network with deep learning and classification this audio files.

Now,i want to apply wavelet transform to these files and create their pictures but i can't.I've done create pictures, using Fast Fourier Transform (fft) and Discreate Cosine Transform (dct) conversions before.Like THIS:

• Read audio file and control this audio has 2 channel or 1?If audio file has 1 channel, then put this one,in matrix :

[y,Fs] = audioread(file_name);
[ch1,ch2]=size(y);
if ch2 ==1
y=y(:,1);
z=fft(y);
s=dct(y);
A=(z);
l=fix(sqrt(length(A)/3));
A=A(1:l*l*3);

• Make normalization in this matrix(Because variables are must be [0,255]) :

absA=abs(A);
minimum=min(absA);
maximum=max(absA);

A2=(absA-minimum)*255/(maximum-minimum);
%normalization
m=uint8(reshape(absA,l,l,3));

• Picture output code is here :

n=imresize(m,[227 227]);%%227 change
ext='.png';
name=fullfile(strcat('classical',num2str(i),ext));
imwrite(n,strcat('classical(Fft)\',name))

But now, i want to do this wavelet transform.Should i use wavelet toolbox ? or wich wavelet function? How can i apply wavelet transform in theese audio files?