General Description of Voice Biometrics

When we speak, words can be broken down into individual components known as phonemes. Each phoneme is delivered with pitch, cadence, and inflection . These three aspects of voice give each of us our unique voice sound. Even though we are all unique individuals and speak for ourselves , we can all sound very similar. This similarity can come from cultural and regional influences in the form of an accent ; also, we learn certain inflections and pitches from our family. That is, if you spend enough time around someone, you can take on some of his/her voice characteristics. Not surprisingly, we have all at one time or another thought we heard one person speak when it was another.

The voice is a physiological and behavioral biometric. That is, it is influenced by our body and the environment we are in. For example, as children grow and pass through puberty, the voice changes. As we grow older, the voice takes on other nuances . Additionally, the sound of our voice can be different if we are talking in a large opera hall or a phone booth , as both have a very unique set of acoustics that will affect the sound of our voice. Therefore, it is possible that our voice does not always sound exactly the same. This again raises the question of the use of voice as an acceptable biometric for network security.

As discussed, the voice can change based on physiological factors and also environmental factors. Thus, both need to be taken into account when evaluating voice-based biometrics.