This chapter deals with the development of “artificial mouths” in food aroma research. After a brief outline on how aroma is perceived in vivo, the need to develop instrumental techniques that reproduce mouth conditions is explained. The devices described in the literature are then presented, and the difficulties and advances in reproducing oral functions, such as mouth temperature, saliva, breathing and mastication, are discussed. Finally, the artificial mouth designed by the authors is presented as well as the improvements it will bring in food aroma research. In particular, this is the first device enabling the aroma of especially hard food to be studied. By means of this technique, volatile compounds contributing to the aroma perception of all kinds of foodstuffs can be identified and a better understanding of the release of aroma during mastication will be possible.