AlchemyAPI wants to make a type of artificial intelligence known as deep learning accessible not only to giant corporations, but to the public. Over the last year, the Denver company has been weaving the technology into its text mining API, recently announcing updates in the areas of relation extraction and named entity extraction.
If it's speech-to-text services you're after, Vocapia Research is in the game, offering a variety of speech technology services and working with their clients to adapt, fine tune or create products that are relevant for specific applications. One of Vocapia's products is the VoxSigma speech-to-text software suite that is suitable for many languages and a variety of audio data types. The VoxSigma API is available as a Web service via a REST API over HTTPS.