Moving from [ ] to [ ], the body of the tongue is pulled back making the front cavity larger and the back cavity smaller. Thus, the resonating frequency of the back cavity is raised as it becomes smaller and the resonating frequency of the front cavity is lowered as it becomes larger as we go from [ ] to [ ]. If we identify the back cavity with the first formant and the front cavity with the second formant, we can understand the relationship between the shape of the vocal tract and the frequencies of the formants. Consider how the changing shape of the vocal tract causes different formants, i. e. different resonant curves. Think of the highest point of the tongue dividing the vocal tract into a front cavity and a back cavity. We know that the resonating frequency is higher for a small vibrating cavity than for a large one.