When people talk to me on my Galaxy S7, they ALL say they can hear their voice back, as in an echo. How can I fix that? Do I need to go to the USCellular store and lose 2 hours of my evening that I can never get back?!
My boss had this exact same problem on his new phone. I looked @ his phone: he had put his case on upside down, covering the mouthpiece. As the previous person suggested; remove the case and see if that solves the problem. The case may not be the correct fit or may have been put on incorrectly. Check to see if anything is blocking the microphone.