An LLM hallucination is when AI generates information that sounds confident and correct but is completely made up. In an AI voice call, this means your virtual agent might tell a customer something that isn't true and say it with total conviction. One wrong appointment time or fabricated policy can destroy customer trust instantly.
Why AI Makes Things Up
Here's the uncomfortable truth about large language models: they don't actually know anything.
They predict. They generate text that sounds plausible based on patterns they've learned. Sounding right and being right are two completely different things.
The problem in AI voice calls:
- The model generates what seems likely
- Confidence doesn't indicate accuracy
- There's no built-in "I don't know" reflex
When asked about something outside its training data or context, the AI doesn't admit uncertainty. It improvises. And it sounds absolutely certain while doing it.
What Triggers Hallucinations
Missing information: Ask about something not in the AI's context? It'll make something up rather than say nothing.
Pattern matching gone wrong: The model recognises a pattern and completes it, even when the completion is false.
No uncertainty training: AI models are trained to be helpful. Expressing doubt wasn't part of the curriculum.
Types of Hallucinations That Hurt Your Business
Factual Hallucination
Making up facts that aren't true.
AI says: "Our clinic is open until 8pm on Saturdays." Reality: Closes at noon.
Entity Hallucination
Inventing people, places, or organisations.
AI says: "Dr. Sarah Mitchell is our cardiac specialist." Reality: No such person exists at the practice.
Temporal Hallucination
Getting dates and times wrong.
AI says: "I'll book you for 3pm tomorrow—Wednesday the 15th." Reality: Tomorrow is Thursday the 14th.
Availability Hallucination
Creating appointment slots out of thin air.
AI says: "We have 10am tomorrow with Dr. Chen." Reality: Dr. Chen is fully booked.
Policy Hallucination
Promising things that don't exist.
AI says: "We offer a 30-day money-back guarantee." Reality: No such guarantee.