Watching activities online, such as scraping soap, rinsing cars and trimming cow hooves, doesn't require much thinking, yet these videos have brought audio-visual pleasure to many people that helps to relieve stress in their real lives.

Zeng Xiaoyue, a 24-year-old master's degree candidate in biology at Zhejiang University, likes watching such videos because she enjoys the sounds.

"The other day, I happened to watch a video showing a man cooking feed for pigs. He doesn't speak, he just chops vegetables. The chopping sound relieved my pressure," she said.

Her pressure comes from writing a thesis and seeking a job upon graduation. She used to seek help from a psychological consultant because she was diagnosed with depression at a hospital.

Lots of people like Zeng love to watch these types of videos for relaxation. On a video platform, video clips themed "scraping soap" and "repairing cow hooves" have more than 1 million views.

In some such videos, people cut, pinch, tear, scrape, squeeze or press objects in which things are being destroyed. Other clips that have similar effects of decompression show manual labor or production, such as washing carpets, cutting cow hooves and repairing cosmetics powder.

Their movements are usually simple, repeated and smooth, giving the audience enjoyment from their visual and auditory senses, which meets the needs of obsessive-compulsive-type people.

People who are diagnosed with OCD aim to restore chaos to its original appearance or give it a new look. This kind of destruction and reorganization relieves pressure and stress.

The videos show a comfortable ending and leave viewers with a satisfied mood and strong before-and-after contrast which maximizes the release.

Autonomous sensory meridian response is another popular type of decompression video, which focuses on giving a tingling sensation by amplifying subtle sounds.

Video creators whisper, chew, blow or touch something to make smooth and slow sounds.

To cater to viewers, videos for releasing stress present various points that satisfy a variety of people.

Some people love to see squeezing acne and pulling out blackheads, which others feel is so disgusting that they can't watch. Some people love to watch an excavator work, even for a whole day, but some people find that boring.

These videos appeared as early as 2013 on the forum Reddit when someone first coined the term "oddly satisfying" in describing the videos, which has grown into a community of millions.

In the era of short videos, these types of videos have become more popular. Last year, videos with the hashtag "Oddly Satisfying" on Tik-Tok received billions of views.