How to Dictate Text on Your Kindle Fire Tablet
Tap in any text field.
The keyboard appears.
Tap the Microphone button to start recording text.
As you record, you see a recording level meter on-screen.
Tap Done when you finish speaking.
The cloud dictation service processes your speech.
When processing finishes, the text you recorded appears in the field and the on-screen keyboard reappears.
You can tap the Keyboard button at the bottom of the screen to hide the keyboard.