Why does the person I call hear his own echoed voice when I have my headphones plugged in?

[AC Question]

Person I call hears his own echoed voice when I have my headphones plugged in.

I have a Galaxy S5 phone and when I have my stereo headphones plugged in, the person I call hears his own voice and it is very frustrating to talk to me. I have a case on the phone, but when I unplug the headphones, the person can hear me without an echo. I love the headphones so that I can talk hands-free, but I don't know what to do to solve this echo problem.

 

[B. Diddy]

Re: Person I call hears his own echoed voice when I have my headphones plugged in.

Welcome to Android Central! Does this happen with other wired headphones? Have you considered a Bluetooth headset?