I have searched google and asked alot of people but no one could answer me. I want to research this way of singing, it is like having a bass effect while singing, what is this technique called ?
here is a video :*starting from 2:43 until 2:52
To my ears it sounds like "growling". There are many ways of adding "distortion" to the voice and that is one of them. It is common in gospel singing.
To learn the technique, one way is to try to imitate the Cookie Monster and experiment with making it feel comfortable (position of the tounge, jaw, etc). There are also a lot of tutorials on YouTube and the like, but most of them seem to be geared toward Death Metal singing. The technique is the same, though. If done correctly it should not feel uncomfortable and will not damage the vocal cords.
I don't think it has a name, other than singing with a "rasp" or "singing dirty". This is a powerful effect used often in soul music (and inspired by the technique of prominent African-American singers in the earlier days of recorded music, such as Mahalia Jackson). However, there are few voice teachers who would deliberately and knowingly teach you to sing in this manner, because most teachers would feel that singing this way causes fatigue and damages the voice.