Voice Biometrics – Text-Dependent vs. Text-Independent

Voice biometrics systems come in two flavors: text-dependent and text-independent.

Let’s explore the difference…

Text-dependent systems require a person to speak the same pass phrase(s) during enrollment and identity verification. The system compares the base voiceprint from enrollment with the sample voiceprint from verification. The majority of voice biometrics systems are text dependent.

Text–independent systems do not require a person to speak a specific pass phrase during enrollment and verification. The base voiceprint and sample voiceprint can be obtained in the background – even without the person’s knowledge (ideal for forensic applications). Text-independent systems usually require a longer enrollment process to ensure verification accuracy.

Voice Biometrics Defined

Voice biometrics is the measurement of the unique characteristics of an individual’s voice. These characteristics, which are based on an individual’s vocal tract shape and motion patterns, are converted into a mathematical formula known as a voiceprint. This is accomplished by acquiring a live voice sample from an individual and applying a specialized algorithm to convert the sample into a digitized "base" voiceprint.

The voice biometric identity verification process is conceptually similar to comparing fingerprints, and no two voiceprints are exactly the same. By comparing a "sample" voiceprint with the "base" voiceprint, one is able to positively verify the identity of any enrolled individual.