Once the Court's yearlong term begins on the first Monday in October, the pattern is for the Court to hear oral arguments for two weeks and then take a two week recess until around mid-April. During the two week sets of oral arguments, the Court may hear up to four arguments a day, Monday, Tuesday, and Wednesday. (See the Court's visitor's guide to oral arguments.)
Transcripts are posted same day an oral argument is heard. Starting with the 2010 Term, audio from all oral arguments are posted on the Court's website at the end of each argument week, Fridays after Conference, to listen to or download. (From the Court's homepage, look for "Oral Arguments" or "What's New.")
The Court has transcribed and recorded nearly all proceedings since 1953, but does not allow arguments to be broadcast live or filmed. The National Archives is the official repository of the Court's recordings; the Court releases all of its recordings to the National Archives around the start of the subsequent term in October. Audio of opinion announcements is only accessible via the National Archives.
From December 2000 up to the 2010 Term, the Court had allowed same-day release of audio when there was heightened public interest, but this was an extremely rare occurrence and is now discontinued.
National Archives: Finding Aid to their sound holdings
Complete Oral Arguments of the Supreme Court: Microfiche KF 101.8 C65
Landmark Briefs and Arguments of the Supreme Court of the United States: Constitutional Law: KF 101.9 L35
Lexis: Legal > Cases - U.S. > Supreme Court Cases & Materials > United States Supreme Court Transcripts
Westlaw: All Databases > U.S. Federal Materials > Federal Cases & Judicial Materials > Judicial Materials > U.S. Supreme Court Databases > Transcripts of U.S. Supreme Court Oral Arguments:
Selected older transcripts are available. Some selected citations of transcripts for older cases: