How to Stop Echoes in Voice Calls

Photo of Cat Talking in Old Telephone
Cat Talking in Old Telephone. photo © Getty / MamiGibbs Pr

Echo is the phenomenon wherein speakers hear themselves after a brief delay during a phone call or internet voice call. Engineers have been dealing with it since the early days of telephony. Although some solutions mitigate some causes of the problem, echo is still a problem even with the advent of new technologies like VoIP.

Causes of Telephone Echo

The first source is referred to as sidetone. When you speak, your voice is looped back to you. This loop is purposefully designed into phone systems to improve the experience of speaking on a phone. As long as the sidetone is heard at the same moment you speak, you won't perceive an echo. However, hardware problems in phone sets, lines, or software can cause the sidetone to be delayed, resulting in echo.

Echo sometimes results when a call is recorded. It is produced when the sound that is emitted by the speakers are recorded by the microphone. It can also be produced when your sound driver is recording all the sounds you hear. To determine which one of the two bedevils you, perform a simple test: Turn your speakers off or set their volume to zero. If the echo stops — your correspondent can tell you whether it does — your problem lies with the recording process.

Echo created by recording a call is difficult to fix without a change in hardware setup. You may reduce it considerably if you take precautions, such as getting your microphone as far away as possible from your phone speaker. Better yet, instead of speakers, use earphones or headsets. Choose headphones that have echo cancellation with good shields. 

For sound-driver echo problems, you will need to configure your sound driver so that your microphone is the only recording input device.

VoIP Echo

Echo appears more frequently during Voice over Internet Protocol calls than over the public switched telephone network and cellular networks. Problems specific to VoIP technology include:

  • A dysfunction in the echo-cancellation mechanism of your VoIP phone or device, or in the carriers providing the phone service. Defective hardware appears anywhere on the network, such as in a server along the call's route. VoIP software may also be buggy. 
  • A smartphone casing may cause echo.

VoIP breaks voice signals into digital packets that route using the internet. These packets are delivered to their destinations through a packet-switching process and reassembled into the original message at the endpoint. This trip potentially runs into latency (or a noticeable lag) between when the message is spoken and when it is received. Packets may be lost en route, or arrive in the wrong order.

Smartphones and Echo

If you're experiencing echo on a smartphone, start by figuring out which end of the connection produces the echo. If you hear yourself on every call, the echo is your problem. Otherwise, the problem sources from the other person on the call, or in the system beyond your demarcation point.

If your phone generates the echo, try the following:

  • If you're using a smartphone, disable any noise-suppression feature in the call settings.
  • Try removing the case of from your phone — some cases cause acoustic echo completely unrelated to any technology deficit.