remove the noise from an audio signal

Iam using this code

rec1 = audiorecorder(8000, 16, 2);

disp('Start speaking.')

recordblocking(rec1, 2);

disp('End of Recording.');

play(rec1);

y= getaudiodata(rec1);

x2=y(:,1);

and I want to filter out the noise using ellipord filter (or any other suggestion) to apply the filter I need to find a & b and those depends on ws & wp which I dont know how to find or identify them , I've already read the help in matlab but it didnt help that much