I found that siri has its own hidden volume setting while you hear it over the speaker. I found this out because mine had been turned all the way down, and it began to bug me that i could no longer hear siri over the speaker. So watch out that u don't accidentally turn siri all the way down like I did...I was about to go to apple and try and get a new phone because i thought mine had broken somehow. Hope this may help some of you guys.