Roughly half of the federal courts of appeal make their recordings of oral arguments available for download:
1st Circuit – Yes
2nd Circuit – No
3rd Circuit – Yes
4th Circuit – No
5th Circuit – Yes
6th Circuit – No
7th Circuit – Yes
8th Circuit – Yes
9th Circuit – Yes
10th Circuit – No
11th Circuit – No
D.C. Circuit – No (can listen real-time though)
Federal Circuit – Yes
As indicated above, the D.C. Circuit even allows for listening in real-time although it doesn’t make the recordings available for download:[Link].