MATLAB code help please....

Hi,
My name is Jennifer.Iam new to Matlab programming.Iam working on reducing the noise content in audio communication.Iam using Hamning codes for the same.I have a sample code with me,which iam uploading in a zip file.Iam unable to understand how it works.Can someone please explain me how the code is written,what it means and what the different plots mean and how to read them? I have trouble especially with the plots trying to understand them.

Secondly,I want to add a filter to the output of the code obtained from the code so that I can filter the noise out.An Adaptive filter is recommended but not limited to.As long as it can be filtered,that's fine.

Being a beginner,Iam having a lot of trouble trying to understand.Iam trying to read Matlab tutorials at the same time but I have to finish up this work soon before the deadline.So can anyone be kind enough to help me through this please,with atleast one of those requirements,most importantly,the filter thing? I would greatly appreciate all the help I receive. Thank you in advance.