Siri won't be quiet

[GreenSnap]

I have an iPhone 4s and sometimes when I'm in school I'll have my phone in my pocket and then I'll leave on my lap without thinking where my phone is and I'll be holding down the home button do siri will go off and people will hear luckily my teachers haven't heard it yet but i know my classmates hear it
Ik that u can turn off Siri but then when u turn her back on u have to reteach her everything.. Please help

 

[r.j.s]

Don't leave your phone in your pocket like that ...

Turn your phone off in class ... If you are worried about your teachers finding out, then you shouldn't have your phone there in the first place.

 

[verwon]

Turn off the feature to have Siri active from the lock screen and lock your phone.