In its latest version 13.50.52 of Android, youtube is rolling out voice search to help users navigate the app better and faster.
Powered by Google’s standard Voice Input UI, you can activate the Youtube voice search by tapping the microphone button on the top-right corner will load an interface which would show a red microphone pumping as you speak, simultaneously a transcription would appear on the screen, then showing your search results.

Along with, searching for any video through voice search, you can also see the results for any part of the menu searched. The command ‘show me’ would work for Watch History, Subscriptions, and other sections also