temp420

It's different in humming in that it makes no sound at all. In humming you let the air pass, here I guess I'm pushing air up to vocal cords but blocking it before it proceeds from the throat.

One type not mentioned is when you are kind of internally vocalizing (singing, but making no sound, just matching the pitch with your vocal cords without blowing any air) along with the song. While doing this when the singer goes to a pitch I would not be able to follow it makes me feel strange in a pleasant way.

Björk - Yoga does this to me repeatedly starting from around 00:37.

Sometimes you can do this not only for actual lyrics, but other instruments as well. Try to "sing internally" the instrument in the song Röyksopp - Vision One starting at 1:48.

This is euphoric to do while high.