Do you want to know which Speech Recognition API is the fastest one?

Here is a great article that presents benchmarking results for three speech to text providers:
1. Google Cloud Speech API
2. IBM Watson
3. Microsoft Speech Bing API

According to the results, Google Cloud Speech seems to be the better solution as they have the most accurate and consistent results, but it is the most expensive.

IBM Watson suffers a big drop in performance when working with French speech.

Moreover, the response time is way too high for real-time usage.

Microsoft is in the middle with a good response time.

If you want to learn more, here is the article with comprehensive description: https://chatbotsmagazine.com/you-shall-not-speak-benchmarking-famous-speech-recognition-apis-for-chatbots-1c04e8ce2c66