Earphone on/in mobile phone

[Xinfu]

Are my sentences correct?

-After putting the earphone onto your mobile phone and after setting the alarm clock, will the alarm go off outside the earphone? When the earphone is in/on the mobile phone, you should be able to listen to songs using the earphone, but the alarm clock sounds should reach outside, otherwise you wouldn't awake from your sleep.

[Rusty]

... earphone in (or into) your mobile phone ...
will the alarm sound on the external speaker? when the alarm goes off, will it ring externally?
When the earphone is plugged into the mobile phone, ... but the alarm should sound on the external speaker ...

I think the alarm should sound on both the earphones and the external speaker in order to wake you.

[Xinfu]

Thank you.