Now I am looking for creating wav files from a matrix and also to change the frequency of my wav files, any ideas?

@Carl Love 

I already know how to get the data from the plot, it was as simple as using the command : getdata(plot)

Thank you all for your time and help, 

pitifully I could not solve my problems with the information that you gave me,
You can download here a small Example of what I am doing

I´ve got a wav file (maplesoft example) and I can plot it with the command Preview, now I would like to know the value of every point of the plot.

If I try to read the Array with the command: audio1[1], for example, it gives me a value that it´s not useful to me
(don´t know what this value means neither) , because I need two values, Axi y --> Amplitude , and Axi x--> Time

 So I need a list(Matrix or Array) with all the values of the graph in the correct “x” or “y” axis order. How can I get it?

How can I change the frequency and format of a wav file?

https://mega.nz/#!u8k3zApL!l6yYoi14P7Cq8ob_-tN3oxNCK9GqDvm-X3vYoSize3M

PD: I don´t know how to upgrade the worksheet with the green arrow, using maple 2015 and couldn´t find that arrow anywhere

@tomleslie 

Yes Thank you I used that help already but cannot find how to get the values of every point of the wave still, when I plot the wav file i would like to know all the values (X and Y axis)in a list or vector, Do someone know about that?