Chrome blocks a lot of stuff on file:// protocol,this includes the
webkitSpeechRecognition api, therefore you are unable to access this property in the window.
Your best option (if you don't have a server or a github page) is to run artyom from a local webserver (localhost with xampp or wampp) or execute chrome from the start with the flag
--allow-file-access-from-files. (read more possible solutions here).