It's never necessary or required to soak beans before you cook them.
I cook beans all the time in my slow cooker while away at work and I just put the beans in the slow cooker in the morning and add some water and then turn the slow cooker on and let the beans cook while I'm away at work.
I then come home 9 hours later and the beans are fully cooked and ready to eat.
The reason some people soak beans in water overnight is mainly to help the beans cook faster the next day and also remove the chemical from the beans that cause gas in your stomach.
So if you want to reduce the gas buildup in your stomach then soaking them the night before cooking them and then replacing the water with fresh water before cooking them will help the beans cook faster and remove the chemical from the beans that cause gas buildup.
Then you'll experience less gas in your stomach and less farting as a result.