Voice authentication is back in the news with another tale of how easy it might be to compromise.
University of Waterloo scientists have discovered a technique which they claim can bypass voice authentication with “up to a 99% success rate after only six tries”. In fact this method is apparently so successful that it is said to evade spoofing countermeasures.
https://uwaterloo.ca/news/media/how-secure-are-voice-authentication-systems-really
If an attacker is determined enough to find or create five minutes of your voice recordings, they are unlikely to be deterred by the (probably much easier) task of finding out your birth date.