Voice cloning: software, voice changers and PVC pipes

AI voice cloning software can learn how someone sounds from recordings and then say anything in that voice. In January 2024, New Hampshire voters got robocalls in which a cloned Joe Biden told them not to vote in the primary. A magician hired by political consultant Steve Kramer said he made the audio with ElevenLabs, which then shut down his account. The FCC fined Kramer $6 million (a New Hampshire jury later acquitted him of separate criminal charges), and earlier that year it ruled that AI-generated voices count as “artificial” under US robocall law.

You don't always need AI. Real-time voice changers shift pitch and timbre during a live call. Researchers at UW–Madison went further with a purely physical trick: speaking through PVC pipes cut to the right length and diameter to mimic a target's vocal resonance. Against automated speaker-identification systems, the tubes fooled the machine for 60% of 91 voices, compared with 6% for unaided human impersonators. Because the change is analog, it slipped past filters designed to catch digital fakes, even though people could still hear it was a different person.

The defence is the same for people and machines: never treat a voice as a password. Hang up and call back on a number you already have, agree a family or team code word for urgent money requests, and prefer passwords plus MFA over voice biometrics for anything important.