Gentle

Gentle is a specialized forced alignment tool built on the Kaldi ASR toolkit, designed to synchronize speech audio with a corresponding text transcript. In the 2026 AI landscape, Gentle serves as a critical infrastructure layer for multimodal synchronization, enabling sub-millisecond word-level timing essential for high-fidelity AI animation, automated video editing, and advanced accessibility services. Unlike general-purpose speech-to-text engines, Gentle excels at reconciling 'messy' transcripts with audio by employing a phonetic-aware search strategy. Its architecture allows it to handle out-of-vocabulary (OOV) words by falling back to phonetic matching, making it a preferred choice for specialized domains like medical, legal, and creative arts. As of 2026, it is frequently deployed within Dockerized microservices to power 'Descript-like' editing features in browser-based DAWs. Its technical position is unique because it provides the 'ground truth' for timing where LLM-based transcriptions often struggle with precise temporal alignment. It remains the backbone for open-source VTubing workflows and automated closed-captioning pipelines that require exact word boundaries.