Hallucination (in transcription)

In speech recognition, hallucination is when the model outputs fluent text that was never spoken — typically repeated phrases or invented sentences appearing during silence, music or noise.

Hallucination is a known failure mode of large speech models like Whisper, concentrated in long non-speech stretches. Pipelines defend against it with voice activity detection, silence trimming and repetition filters.

If a transcript contains a suspiciously fluent sentence during what you remember as silence, that is what you are looking at — spot-check against the audio.

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