This is what the company says in a blog post: Microsoft has removed support for Cortana on Windows 10. These instructions no longer work unless you’re running an old version of Windows 10 like Anniversary Update. Note: Cortana is decoupled from Windows Search.
With Cortana in Windows 10, you can avoid this issue by making it respond to your voice only.
However, if I have a podcast or TV show playing in the background, sometimes it will be triggered (especially when listening to tech podcasts). I have “Hey Cortana,” which enabled me to ask questions, set reminders, and use other features by using my voice.