STT Evaluation is the process of measuring how accurately a speech-to-text (STT) system transcribes spoken audio into text. It uses metrics such as Word Error Rate (WER) and transcription accuracy, run against benchmark datasets and real-world audio that reflects accents, background noise and domain-specific vocabulary.
In Voice AI, speech recognition sits at the very front of the pipeline, so STT errors cascade into intent detection, LLM responses and analytics. Evaluating STT with WER, domain vocabularies and noisy, accented audio ensures voice agents reliably understand callers before anything else happens in the conversation.