This is a super serious issue to me as I spend a lot of time with my headphones in while traveling on planes, on quiet cars in trains, and in the library studying.
What I have noticed, only after pissing off a lot of people around me, is that when the headphones are plugged into this device you receive notification sounds via the headphones as well as the external speaker.
This is NOT how this should be working, it doesnt work like this on any other handset I have ever owned, driod incredible, droid bionic, iphone, etc. All of them route notification sound ONLY to the headphones when they are plugged in. What sense does it make to have sounds also come out of the external speaker while headphones are plugged in?
I looked in all the sound options throughout the entire phone and have found 0 settings that can control this. And I did a quick search on google, and this has apparently been an issue with other Samsung devices I wasnt at all aware of before I purchased this note 3 at full price..See link below to other convos on the subject.
https://www.google.com/search?q=external+speakers+active+while+head+phones+are+plugged+in+samsung&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=fflb
I do not know who are where to turn to at this point but this, in my mind at least, is a huge issue. There are only two solutions at this time:
1) totally mute all your sounds via settings when you have your headphones on. This option flat out sucks, as then you do not hear any notifications coming through the headphones either.
2) download an app called soundabout. This also shouldnt be necessary. I have 2 issues with this. I just paid 700 dollars + tax for a phone, why should I need an app to make it function normally. And second, how do I know this app is active at all every time I plug my head phones in. I don't. So I may think the app is working, but in reality it may not be and I still may be causing a ruckus for all the other people in my near vicinity.
I honestly advise everyone to test this, as I have, plug a pair of headphones in(and yes I have tried multiple sets of headphones) and you will notice the same issue, sound comes out from both headphones and external device speaker.