Speech researchers have been studying articulation (the co-ordinated movements of the speech organs) and the acoustic features of speech since the 1700s (Kempelen, 1791/1989). Special equipment is needed to examine the movements of the articulators (vocal folds, tongue, lips) as most of these structures cannot be seen during the production of speech. As the study of articulation requires complex instrumentation and all articulation-focused measurement methods modify speech production to some extent, the question arises as to why articulation should be examined at all. As opposed to articulation, the acoustic signal is readily observable and analyzable, and the acoustic analysis of speech does not introduce any major measurement-related artefacts to the data. Furthermore, the tools of acoustic analysis are easily available and are relatively inexpensive. To the necessity of articulatory research, the Quantal Theory provides an explanation (Stevens, 1989). According to the Quantal Theory of speech production and perception, the articulatory gestures have acoustic consequences; however, the magnitude of articulator displacement is not proportional to the magnitude of change observable in the acoustic signal, as the relationship between articulation and its acoustic consequences is not linear. It follows that a minor change in articulation might result in a significant change in the acoustic output, if taken place in the “critical region” and vice versa, major differences in articulation might not induce any differences in the acoustic signal. The adjective quantal refers to this non-linear relationship (Stevens, 1989). The importance of the study of articulation is further highlighted by the fact that although certain acoustic parameters highly correlate with articulation, the acoustic parameters cannot be identified with specific articulatory movements in a one-to-one manner. It is commonly known that although the first formant (the first resonance) of the vocal tract is primarily influenced by the vertical position of the tongue, it is also modified by the displacement of the jaw, which is, to some extent, independent of the tongue position. Similarly, although the second formant is primarily determined by the horizontal position of the tongue, it is also influenced by the movements (especially rounding) of the lips (Stevens, 1998). As a corollary to this, the articulatory movements cannot be reconstructed solely on the basis of the acoustic characteristics of the speech signal.