The search results do not explicitly link "AIFF" (an uncompressed audio file format) to a specific plot point in this episode. It is likely that this keyword refers to high-quality audio rips or specific digital file versions of the episode found in archival or enthusiast circles rather than an in-show plot element. "Young Sheldon" Legalese and a Whole Hoo-Ha (TV ... - IMDb
Frustrated by the "hoo-ha" over money, Sheldon delivers a characteristic rant, declaring that he wants his work to be about science, not profits.
ffmpeg -i young_sheldon_s06e08.wav -c:a pcm_s16be -f aiff young_sheldon_s06e08.aiff
Ensure you have access to the episode via a legitimate source (Max, Amazon Prime Video, iTunes, or a physical DVD).