APIs for converting Voice/Audio data in to text

I am working on a iphone apps in which i am storing the vo开发者_JAVA技巧ice of users as audio file and want to display in text.

How it will be ...any idea about APIs ??

Thanks, Aaryan

Have you seen CMU Sphinx ?

Particularly, pocket sphinx (written in C)

While more recognition oriented, it's been used for transcription before, so it will depend on what exactly you need:

Further, have you considered a non-native/local API, i.e. a web service you could call with your voice data, or are you adamant about a native library/API ?

For example, Ribbit has a platform for these sorts of things, and does support transcribing voice to text

"How do I enable voice-to-text transcriptions? Available as a paid service, voice-to-text transcriptions are automatically available through the Ribbit API. Please use the $25 Free signup credit to try the service."

There is one app that does this already: Jott. The way they do it is to send the file to transcribers in India! (source)

You will have to develop the voice recognition engine yourself I'm afraid. No library that I know of can do this. Apart form that, the iPhone CPU would probably not be powerful enough.