Can I play music while the earphones are connected to a tablet/phone?

I wanted to do one of those pranks with my friends where you plug in earphones into a computer and then music plays on the speakers while people think you're earphones/computer aren't working.I thought of doing the same with an Android tablet I have but the only thing is, I'd like to connect it fully in and have music playing both on the speaker and in my earphones.I heard it's not a software component but a hardware one that controls turning off the speakers so I'd have difficulty doing it but I could be wrong.Anyone have an answer? via /r/AndroidQuestions http://ift.tt/2rV5IqD