The OYEZ site is a great site for listening to recordings of oral arguments from the Supreme Court (going back to at least 1956).
Here is a link to the oral arguments from patent cases at the Supreme Court: [Link].
Here is a link to the oral arguments from trademark cases at the Supreme Court [Link].
And, here is a link to the oral arguments from copyright cases at the Supreme Court [Link].
All content on oyez.org and other sites and projects maintained by Oyez is released under the Creative Commons Attribution-NonCommercial 4.0 International License.