CMU Sphinx vs Gladia

CMU Sphinx is a free, open-source toolkit for developers building speech applications. Its maintained components are PocketSphinx, a lightweight C speech recognizer library, and SphinxTrain, tools for acoustic model training. The toolkit is designed for efficient recognition on low-resource platforms, and its documented interfaces support keyword spotting, grammar and language-model searches, and word-level segmentation. Recognition requires acoustic and language models. The toolkit is language-independent, with prebuilt models listed for English, Chinese, French, Spanish, German and Russian. SphinxTrain supports adding a language through data collection and cleaning, model training and testing. Noise handling uses MFCC features, noise tracking and spectral subtraction. The BSD-like license permits commercial distribution. Possible applications include voice control, language learning, transcription, closed captioning, speech translation and voice search. Decoders require PCM input, so encoded audio must be converted before processing. The project documents a PocketSphinx Android library and demo, but cautions that its Android tutorial may no longer work with current tools. The homepage announces PocketSphinx 5.1.0.

Gladia provides audio infrastructure through an API for recording, transcribing, and enriching audio. It offers asynchronous and real-time transcription, including live streaming, with Starter supporting 100+ languages and automatic language detection and switching. Listed audio tools include speaker diarization, sentiment analysis, PII redaction, entity detection, and audio-to-LLM processing. Developers can use Python or Node.js SDKs, WebSocket streaming, or REST uploads; named integrations include Pipecat, LiveKit, Twilio, Retell, Zapier, Make, and n8n. Transcripts can include speaker labels and timestamps, and SRT and VTT are listed export formats. Starter is listed at free and includes 50€ in one-time credits that do not expire. Flexible pay-as-you-go Starter rates are $0.61 a month for asynchronous transcription and $0.75 a month for real-time transcription. Hourly call and total audio limits vary by tier. Gladia also offers GladiaFlow, a desktop voice dictation app for Mac and Windows; its code is available under the MIT license.