Beyond Transcription: Building Voice AI That Understands Conversations — Hervé Bredin, pyannoteAI
Jun 5, 2026 · 25:20
Hervé Bredin, chief science officer at pyannoteAI, argues that speaker diarization benchmarks are misleading because they use headset audio while users rely on table microphones—Nvidia Parakeet reports 11.4% word error rate on AMI headset data but gets 26% on the same dataset's table mic. The episode covers how speaker diarization (who speaks when) is harder than it looks, especially when combining with transcription: overlapping speech, timestamp disagreements, and words falling between speaker boundaries create errors. Bredin demonstrates pyannoteAI's Precision 2 model achieving 3% diarization error rate (DER) against a 5% baseline on a two-speaker phone call. State of the art today: 2% DER on clean telephone calls but 41% in a noisy restaurant, showing the problem is far from solved. The reconciliation between diarization and STT is handled by a proprietary orchestration that works with any STT model.
