Custom vocabulary vs. custom spelling: which one to choose for better transcripts

Speech-to-text (STT) systems often struggle with accurately transcribing brand names, technical acronyms, and non-standard pronunciations, which can disrupt workflows and erode trust in call centers and customer service platforms. Gladia offers two tools to address these issues: custom vocabulary and custom spelling. Custom vocabulary uses phoneme similarity to correct words the engine mishears, while custom spelling replaces words the engine recognizes but misspells. These tools are complementary, not interchangeable, and selecting the wrong one can create further problems. Custom vocabulary addresses audio-to-text issues and requires tuning, while custom spelling tackles text-to-text errors and is deterministic, eliminating false positives. For situations requiring precise transcription, such as compliance or healthcare, the correct application of these tools is critical, and platforms that allow users to manage their own vocabulary lists can enhance transcription accuracy without additional engineering effort.