Voice based authentication using the null frequencies

Abstract

The human voice has many features that have been used for centuries for authenticating others. That was/is the case when someone calls for one other, but that is even more relevant when the communication is made at distance, like when using the phone. These facts served as inspiration for software designers that started to investigate how the voice can be used in an automatic way to provide or deny access to valuable places, physical or logical. The range of frequencies covered by the human voice is well known, although it is not the same for each person, and this data has been used to feed the several algorithms that have been developed in the past years. What we now have found is that one person, for each sentence, has some not used frequencies. In this paper we will present some studies that indicate that those unused frequencies alone can be used to authenticate and even to recognize the users.