Overview

The three ways to produce captions in Line 21 and when to choose each: professional human captioning, automatic speech recognition, and caption file playback.

One of the fundamental choices when setting up live captioning projects with Line 21 is to decide which method of captioning you want to use. There are three main methods of captioning:

Human Captioning - hire a human writer or a respeaker;
Speech Recognition (ASR) - AI models that transcribe the audio to text;
Caption Playback - use an existing subtitle file for technical testing or pre-recorded live streaming;

Each method has its own advantages and disadvantages, and the choice of method will depend on your specific needs and requirements. Contact us if you are unsure.

Method	Advantages	Disadvantages
Human Captioning	High accuracy, human-like captions, ability to handle complex content	More expensive, limited scalability, higher latency
Speech Recognition (ASR)	Fast, scalable, ability to handle large volumes of content	Can have lower accuracy if not customised properly
Caption Playback	Perfect accuracy, automated	Inflexible, fit only for niche situations

Traditionally human captioning was considered the only sound solution for high stakes live events. However, with the advent of AI models that can transcribe audio to text with higher accuracy, at a fraction of the cost, and the ability to proofread in real-time, many organisations are now considering using AI-powered captioning for their live events. Line 21 supports both of these methods.