Google lets you use your voice instead of your keyboard in Google Docs and Google Slides. This option, however, is only available in the Google Chrome browser.
Steps
Method 1 of 2: Turn on voice typing in Google Docs

Step 1. Check your microphone
Make sure your microphone is on and ready to use. If you're using a Mac, see Turn on a microphone on a Mac. If you are on Windows, see Recording sound with a PC to test recording.

Step 2. Open Chrome
The shortcut is in the folder Applications on Mac and in the section All the programs menu To start up on PC.

Step 3. Open Google Drive
If you are not yet signed in to your Google Account, follow the onscreen instructions to be able to sign in.

Step 4. Open a document
Open the document you want to edit. If you want to create a new document, click + New in the upper left corner of the page, and then select Google docs.

Step 5. Click Tools
The button is located at the top of the window, in the toolbar of Google docs.

Step 6. Select Voice Entry
The microphone panel will then appear.

Step 7. Activate the microphone
When you are ready to speak, click on the microphone.

Step 8. Start talking
Say out loud what you want to write. Speak clearly at a normal volume and with a steady speed. The words will appear on the screen as you speak them.
- To add punctuation or wrap around, use these expressions: Point, Comma, Exclamation point, Interrogation point, At the line, New paragraph.
- You can also use voice input for the layout of your text. With for example, the following commands: Bold, Italicize, Underline, All caps, Capitalize, Highlight, Increase font size, Double line spacing, Align center, Apply 2 columns. At this time, voice layout commands are only recognized in English.
- You can also move around the document with your voice. Say Go to Where Move to, followed by the element (for example, Start of paragraph, End of document, Next word, Previous page). As with the layout, movement commands are only recognized in English.

Step 9. Close the microphone
When you're done, click the microphone again to close it. What you say from now on will not appear.
Method 2 of 2: Enable voice input for presenter comments in Google Slides

Step 1. Check your microphone
Make sure your microphone is on and ready to use. If you're using a Mac, see Turn on a microphone on a Mac. If you are on Windows, see Recording sound with a PC to test recording.
You can only use voice input for presenter comments, not in the slides themselves

Step 2. Open Chrome
The shortcut is in the folder Applications on Mac and in the section All the programs menu To start up on PC.

Step 3. Open Google Drive
If you are not yet signed in to your Google Account, follow the onscreen instructions to be able to sign in.

Step 4. Select a slideshow
Click on the slideshow you want to edit. This will open the file for editing.

Step 5. Click Tools
The button is located at the top of the window, in the toolbar of Google Slides.

Step 6. Click Dictate Presenter Comments
This will bring up the presenter comments panel, as well as a small one with a microphone.

Step 7. Activate the microphone
When you are ready to speak, click on the microphone.

Step 8. Start talking
Say out loud what you want to write. Speak clearly at a normal volume and with a steady speed. The words will appear on the screen as you speak them.
- To add punctuation or wrap around, use these expressions: Point, Comma, Exclamation point, Interrogation point, At the line, New paragraph.

Step 9. Close the microphone
When you're done, click the microphone again to close it. Any changes you made to the document will be saved immediately.