AT&amp;T has its own &quot;Watson&quot;...but it requires signing up for a premium account, which I think involves an upfront cost:<p><a href="http:&#x2F;&#x2F;developer.att.com&#x2F;apis&#x2F;speech" rel="nofollow">http:&#x2F;&#x2F;developer.att.com&#x2F;apis&#x2F;speech</a><p>Twilio has one that also requires payment:<p><a href="https:&#x2F;&#x2F;www.twilio.com&#x2F;docs&#x2F;api&#x2F;rest&#x2F;transcription" rel="nofollow">https:&#x2F;&#x2F;www.twilio.com&#x2F;docs&#x2F;api&#x2F;rest&#x2F;transcription</a><p>It limits input audio to 2 minutes. And I would have to guess that its model is specifically tuned to phone messages, i.e. one speaker, relatively clear and focused audio, and certain probabilities of phrases.