The Audio is an mp3 file made available through the United States Conference of Catholic Bishops web site: http://www.usccb.org/nab/nabpodcast.shtml.

Click on the Audio link and if your computer has an mp3 player you should be able to hear the reading through your computer speakers.

If you wish to save the mp3 file on your computer (perhaps for transfer to a portable device), right click on the Audio link and select "save Target as".

If you have problems with the audio link for a reading, click on the following Listen to Podcast link and then drag the blue button on the right until you see the reading you would like to listen to then click on the reading:
Listen to Podcast