Speech processing typically refers to the various mathematical techniques that are applied on an audio signal to process it. It may be some simple mathematical operation or some complex operation. It's a special case of digital signal processing. However, we are not typically dealing with speech processing as a whole entity. We are interested only in a specific area of speech to text conversion. It is to be noted that everything in this chapter is to be performed by the Edison itself without accessing any cloud services. The scenario that this chapter will tackle initially is that we'll make the Edison perform some tasks based on our voice commands. We'll be using a lightweight speech processing tool, but before we proceed further with all the code and circuits, make sure you have the following devices with you. Initially, we'll walk you through switching an LED on and off. Next we'll deal with controlling a servo motor using voice commands.