If the people you are speaking to have microphones of their own and are receiving your voice through speakers, their microphones can pick up the sound from their speakers and send it back to you. The simplest and most likely cause of an echo is not even caused by your microphone. Click/tap on your microphone device under Input devices, and click/tap on the Enable (default) or Disable button. Click/tap on Sound on the left side, and click/tap on the Manage sound devices link under Input on the right side. Open Settings, and click/tap on the System icon.