Using lowpass filter for channel simulation

Hello

I need to simulate some audio files using lowpass FIR filter (Digital). I have tried doing it using simulink but I need to do it using a code. Can anyone please tell me how to do it? I am facing a problem as I dot know how to incorporate the audio file(.wav). It would be great if anyone could give me some ideas of doing it.

Thank you:)

[Wayne King]

I see you had a memory issue reading your .wav file. Do you have the DSP System Toolbox in your installation?

[olivia]

Yes, I have the DSP system toolbox installed. I broke the audio file into smaller chunks as well but it still does not work.