Are you or the other person using the speaker phone function? Does this happen during conference (3 way) calling? If you're using the speaker phone function, especially during a conference call, you're likely to hear an echo. I've had this very same issue with a different phone and the only solution I found was not to use speaker phone.
Answers & Comments
Are you or the other person using the speaker phone function? Does this happen during conference (3 way) calling? If you're using the speaker phone function, especially during a conference call, you're likely to hear an echo. I've had this very same issue with a different phone and the only solution I found was not to use speaker phone.
Good Luck!