The phrase "microphone icon" refers to a small picture or symbol that represents a microphone on a device, such as a computer or smartphone. Full definition
Along with this, you'll also find a new microphone icon on the search bar. (androidcentral.com)
Then, you should see a circular white microphone icon in the bottom row. (tomsguide.com)
A new microphone icon, when tapped, allowed listeners to ask for specific artists, tracks, or albums, but also request genres and custom playlists. (slashgear.com)