A very basic overview of Web Speech API, along with an example.
This API allows you to incorporate voice data into applications. It can be used in two ways.
SpeechSynthesis)Allows application to read out the text through device output like speakers. Voice types can be changed through SpeechSynthesisVoice objects.
SpeechRecognition)Recognise voice from an audio input such as device input. The SpeechGrammar interface is used for grammar the app should be able to recognise.
To read more about grammar click here.