The human-machine interaction through audio interface, has gained a lot of attention in recent years. Many application, like google assistant, Amazon Alexa, Siri, are nowadays everywhere in the world and work only through vocal interaction. The motivation of the abrupt diffusion of these systems is the ease of accessing the functionalities of such devices through the natural voice. The trend for the future seems to be a pervasive diffusion of these systems. Typically, a small local device is responsible of collecting the audios and transmits them to a remote server, where a complex system, able to translate the audio into actions, is implemented.