The Bandwidth Python SDK by Bandwidth provides tools for users to use the Bandwidth API with Python applications. The Bandwidth API allows users to make calls to get information about an account, get a list of transactions made on an account, as well as calls for phone numbers, messages, calls, media, applications, errors, and other resources.
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.
AOL has just launched a new telephony web service for developers: the Open Voice API. This API is intended to "provide third-party developers and VoIP device manufacturers with open standards protocols that will enable them to easily integrate the AIM Call Out service into softphones, as well as SIP-enabled hardware and cell phones with wi-fi connectivity."