1. A system for activating a plurality of functions based on speech input, wherein the system is embedded in an apparatus, comprising: a memory storing a plurality of states, wherein each state is associated with at least one function from the plurality of functions and a data model from a set of data models; an automatic speech recognition (ASR) engine for interpreting, based on the data model, the speech input into a functional input for activating the function; a plurality of controls, wherein there is one control for each state forming one-to-one correspondence between a control and a state, and wherein the control, upon activation, generates a signal associated with the state; a state transition module for transitioning the system to the state based on the signal, such that the system interprets the speech input using only the data model associated with the state, and execute the function associated with the state according to the functional input; and a processor operatively connected to the memory for executing the ASR engine and the state transition module.