Samsung Galaxy S5: the two Speakers always on???

[alawadhiya]

Hi I just bought Samsung Galaxy S5 two weeks ago

when I answer calls people next to me can hear the entire conversation through S5 back speaker without me clicking on the speaker button, if I do click the speaker the voices get magnified however if I un-click the speaker it is still working but with lower volume nevertheless the call can be still heard through the speaker and it is very clear

why is the two speakers always (front & back) on at the same time?

is there a way to deactivate the back speaker (the speaker is already turned off (un-clicked) though voices can still be heard very clearly through it)

is this a bug? I read somewhere it had to do with chrome update?

Anyone help please :'''''''(

my only solution now is to use a headphone to have some privacy :-[:-[:-[:-[:-[:-[:-[

I am using the latest update Kitkat and performance improvement update

 

[sjaduae]

if you are using svoice to answer or call phones there is a setting to auto start speaker phone uncheck this in svoice settings to see if that helps