The Interrogation Room-Voice ContradictionDetector

The Interrogation Room is a real-time voice analysis app built for live two-person interrogation scenarios. One microphone, two people: a detective and a suspect. AssemblyAI's Realtime Speech-to-Text API listens to the full conversation, transcribes both speakers, and uses speaker diarization to automatically separate detective turns from suspect turns. The AI works silently in the background as an analyst. It logs every claim the suspect makes — times, locations, people, objects — into a structured claim ledger. On each new suspect statement, it runs a contradiction check against everything said before. When a contradiction is detected, the detective's dashboard fires instantly: the screen flashes, the two conflicting quotes appear side by side with their timestamps, and a contradiction card is permanently added to the evidence board. The detective sees a live noir-styled dashboard with a two-voiced scrolling transcript, a suspicion gauge rising in real time, a pulse chart tracking the suspect's speech rate, and a contradiction board filling up as the interrogation unfolds. Action buttons let the detective flag evidence, manually raise suspicion, or call for a pause. At the end of the session, a full case report is generated: a suspicion timeline, a skill radar scoring consistency and composure, a talk ratio breakdown, a weak-spots chart by claim category, and a shareable cinematic verdict poster the detective can export and post. Built on AssemblyAI Realtime STT with speaker diarization, Next.js 14, Zustand, Recharts, and Framer Motion. Deployed on Vercel. Use cases include law enforcement training, legal cross-examination practice, debate coaching, and live game experiences.