The main advantage that voice biometrics has over other biometrics is its ability to prevent spoofing in the case of a data leak. If your fingerprint or retina data were to be stolen, the biometric security would be compromised beyond repair; you cannot (easily) change your retina or fingerprint. However, because voice biometrics employs text-dependent characteristics, you can simply adopt a new voiceprint phrase and wipe out all previous enrollments in the case of a biometric data leak. Furthermore, in specific situations where fingerprints or retinal scans cannot be used (such as laboratories where gloves leave residue on fingers and gloves cannot be removed until one has exited the lab), voice biometrics possess added advantages.
Another main advantage is the Equal Error Rates are much lower than Finger, Iris, and Face. See Chart below: