They are and I'm not an expert on this theory .. I haven't watched this episode but I'll definitely look for it now. What did they use as a stylus? ..
"Pottery Record (Archaeoacoustics)
Myth: Scientists have been able to play back sounds inadvertently recorded onto ancient pottery
Myth Variant: On an episode of
CSI, the investigators are able to retrieve a recording from a piece of pottery at the crime scene.
Making recordings
The MythBusters used two setups to do their recordings onto the pottery. In the first setup, which was meant to test the historical version of this myth, they spun a piece of potter on a pottery wheel with a stylus etching into its side. The stylus sat on top of a drum, which transmitted vibrations. Tory and Kari took turns screaming sayings to be recorded.
For the "forensic show"/CSI variant, they cut some straw from a broom and held it against the side of the spinning pottery. In their first recording with Kari, they were worried that wind from Kari's mouth was moving the straw instead of her voice. They added a wind screen and did some more recordings.
Playing the recordings
Grant dissected some turntables to read their pottery recordings back. The stylus on modern turntables is too sharp for pottery, so Grant made a glass stylus by heating a shard of a wine glass. He heated up the shard and stretched it out into a thread. He then re-heated one end of the thread into a little bulb so it could be glued to the turntable arm.
The build team gathered around their pieces of pottery as Grant held the glass stylus on them for playback. They heard some promising whoops and squeaks, but nothing they could discern as a real recording.
They took tapes of their playback to DeNoise in SF, which specializes in audio processing. Albert Benichou, sound mastering expert, took his best shot at eliminating the noise from the recording to find some evidence of voices. The best they got for his efforts was a squeak.
busted"
http://kwc.org/mythbusters/2006/10/episode_62_killer_cable_snaps.html
maximus otter