How to change the default microphone used by Voice In?

In Google Chrome and Microsoft Edge, the microphone setting is a browser-level setting.

To check or change the microphone Voice In uses, go to the Voice In Options page. You should see the current microphone being used. Click on the Change button at the end of the line.

This will open the browser's microphone settings page. The circled value below shows the browser's current microphone. To change the microphone used by Voice In, click on the dropdown and select the microphone you wish to use.