The present study starts from the premise that new ways of communication are emerging throughout the years, including the relationship between human and machine, which nowadays, speech is the predominant communicational vehicle. And in this dialogue, there is a search for the adaptation of the machine to our form of communication and a constant need to human s adaptation to the machine s form of communication. This investigation attempts to clarify if systems based on voice interfaces are in fact composed by a model of interaction that is defined as conversation, and if they are actually being supported by the areas of ergonomics, usability, and also by the basics fundaments of conversation theory. This work finds itself structured in four sections: the first one corresponds to the theoretical foundations; the second section embraces data collection, which gathered several interviews with the users of conversational interfaces; the third section is established on the content analysis of the previous interviews; lastly, the fourth section concerns the final considerations of the current experience of conversational interfaces.