Hmmm idk exactly what sound he used, but thats a simple rise build up. You might have to sample that sound though.

You basically lay that sound out for as long as you want. Then, you put it in the mixer and i add the "free fruity filter" to that channel. Next, you'll see a program pop up and you can turn the low pass all the way down, right click on the knob and click "create automation clip" and then you can mess with the line and make it build up or go down or up and down, or whatever you want.

Lemme know if this helps!