CMU Sphinx vs Otter.ai

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.

Otter.ai transcribes meetings into searchable text and provides summaries and action items. Its meeting bot can capture calls on Zoom, Google Meet and Microsoft Teams; the Mac and Windows desktop apps can record conversations without a bot joining. Other listed features include live transcription, speaker labels, note templates, calendar integrations and a searchable archive. It supports six languages and is available through Android, iOS, macOS, Windows and Chrome apps or extensions. Basic is free forever and includes 300 transcription minutes per user each month, three lifetime imported files per user, and a 30-minute maximum per conversation. Pro Annual costs $8.33/user/month, billed annually; Pro Monthly costs $16.99/user/month. Business Annual costs $19.99/user/month, billed annually, while Business Monthly costs $30/user/month. Business includes a seven-day free trial and allows conversations up to four hours. Otter lists TLS encryption and AES-256 encryption for real-time content. Payment options include credit and debit cards and Apple App Store or Google Play purchases.