Real-Time Captioning

The process of converting spoken language into text display in real time, typically with only a few seconds of delay. Professional real-time captioning (CART) uses stenographers with specialised shorthand keyboards who can type at speaking rates of 170+ words per minute, charging $100-$300 per hour. Alternative approaches include automatic speech recognition (ASR), which is cheaper but less accurate especially in noisy or multi-speaker environments, and collaborative captioning where multiple non-expert typists contribute portions of the transcript that are merged algorithmically. Real-time captioning is essential for deaf and hard of hearing people in live events, classrooms, and meetings, but also benefits people with situational hearing difficulties, non-native speakers, and anyone in noisy environments. A key challenge is that speaking rates often exceed reading rates, causing caption readers to progressively fall behind.