This paper presents an original study of compensatory properties of the vocal tract. Indeed, due to the high dimension of the articulatory space, exploring all the compensatory effects of the vocal tract is a hard task, even if we could use real data (MRI, x-ray). For these reasons, we use a codebook representing the sampling of the articulatory space. Sampling such a space is difficult because of the non-linear nature of the mapping between articulatory and acoustic spaces. We linearize the mapping by decomposing the articulatory space into regions, the mapping is quasi-linear in. An exploration method of the codebook is developed, in order to study articulatory variability. We present different vocal tract configurations of some vowels and their articulatory characteristics.