This paper describes the importance of the GUIs (Graphical User Interfaces) to the control of digital sound synthesis. Is intended to highlight the cognitive problem present in synthesizers as a consequence of the usage of technical acoustical language on their interfaces. Psychoacoustic scientists have tried to overcome this cognitive gap developing a unified model of perception where a musician is able to interact with sound using a perceptual interface rather than a scientific one. As these efforts have not currently reached their goal, different approaches are addressed to design interfaces that adapt to the user, rather than the user adapting to them.