Bob Ross’s painting is now seen as an early example of ASMR. While the team making that show was not aware of the phenomenon that would dominate YouTube decades later, they did create the audio soundscape of the show quite intentionally. It was a show, in many ways, as much about sound as painting:
The show had a peculiar audio setup. The sounds Ross makes with his painting — the scraping of palette knives and his signature brush cleanings — are picked up almost as well as his voice.
Kowalks says this was done on purpose. “We were aware and Bob was aware that from the very beginning it was about the sounds that he was making.”
The sounds and how they were recorded are crucial. ASMR is usually triggered aurally, particularly when the person causing them gives personal attention, as Ross did when he talked directly to the viewer.
Dmitri, who creates videos on the YouTube account MassageASMR, says the audio was almost too perfect. “Whoever was recording onto audio knew that these sounds were quite important. It’s almost like trigger, trigger, trigger, trigger, trigger, trigger.” (Source)