Headphone not shutting down speakers?

[soloist_huaxin]

I was watching the xbox one press on my Lumia 920 with my headphone(Senheiser HD202, no mic) plugged in, and when I take my headphone off(but still plugged in), I can hear notification sounds(email) coming out of the bottom speakers! shouldn't plugging in headphone shut off speakers? I tried other apps and they work as intended(sound coming out only from headphones)

 

[Al_2]

If your phone rings with headphones on it'll come out of the speakers too. Seems a bit stupid to me. If I use headphones I switch the ringer to silent to stop that happening!

 

[soloist_huaxin]

so this is a OS-level thing/bug/feature? considering how weird they did with the vibrate switch for ring/app/etc...