Echo on VoIP Calls: Why It Happens and How to Fix It

Understanding Echo on VoIP Calls

Echo on VoIP calls is when you hear your own voice repeated back to you with a slight delay. It can range from a barely noticeable reflection to a distracting repetition that makes conversation difficult. Echo is a common VoIP complaint, but it is almost always fixable once you understand the cause.

Types of Echo

Acoustic Echo

Acoustic echo occurs when sound from a speaker is picked up by a nearby microphone and sent back to the original caller. This is the most common type of echo and typically happens when:

A speakerphone is being used and the speaker volume is too high
The microphone and speaker on a desk phone or headset are too close together
The call is being taken in a room with hard, reflective surfaces

Hybrid Echo

Hybrid echo occurs at the point where a VoIP call connects to the traditional PSTN (Public Switched Telephone Network). When a VoIP call is routed to a landline, the signal passes through a gateway that converts between digital (VoIP) and analogue (PSTN) signals. Impedance mismatches at this conversion point can cause a portion of the signal to be reflected back, creating echo.

This type of echo is typically heard when calling traditional landline numbers and is usually managed by the VoIP provider's gateway equipment.

Network Echo

Network echo is caused by excessive latency on the network. When the round-trip delay exceeds approximately 50 milliseconds, any small audio reflection becomes perceptible as echo. The higher the latency, the more noticeable the echo becomes.

Common Causes of Echo

Speakerphone Volume Too High

This is the most frequent cause. When the speakerphone volume is set high, the microphone picks up the audio from the speaker and sends it back to the caller. The caller then hears their own voice with a delay. Reducing the speaker volume is often all that is needed to eliminate the echo.

Headset or Handset Issues

Faulty or low-quality headsets can cause echo due to:

Sound leakage from the earpiece to the microphone
Damaged cables causing electrical interference
Incompatible headset not properly matched to the phone model

High Network Latency

Even small amounts of echo become noticeable when latency is high. If your network latency exceeds 150ms, any acoustic or hybrid echo will be clearly audible. See our call quality troubleshooting guide for how to measure and reduce latency.

ATA (Analogue Telephone Adapter) Issues

If you are using an ATA adapter to connect traditional analogue phones to your VoIP system, impedance mismatches between the ATA and the phone can cause echo. This is similar to hybrid echo and occurs at the analogue-to-digital conversion point within the ATA.

How to Fix Echo on VoIP Calls

Step 1: Reduce Speaker Volume

If the echo is reported by the person you are calling (they hear their own voice), the issue is on your end. Reduce your phone's speaker volume, especially if using speakerphone mode. Even a small reduction can eliminate acoustic echo entirely.

Step 2: Use a Headset

Switching from speakerphone to a headset physically separates the speaker (earpiece) from the microphone, dramatically reducing the chance of acoustic echo. Use a quality headset that is compatible with your phone model.

Step 3: Check Network Latency

Run a ping test to your SIP server to check latency. If latency exceeds 150ms, address the network issues first:

Enable QoS to prioritise voice traffic
Check for bandwidth saturation
Consider upgrading your broadband connection

Step 4: Enable Echo Cancellation

Most modern IP phones have built-in echo cancellation features. Check your phone's settings or admin interface for echo cancellation options and ensure they are enabled. Common settings include:

Acoustic Echo Cancellation (AEC) — should be enabled
Echo Cancellation Tail Length — increase if echo persists (128ms is a common default)
Noise Reduction — can help reduce background noise that contributes to echo

Step 5: Replace Faulty Equipment

If echo persists after trying the above steps:

Try a different headset to rule out headset issues
Try a different handset — the handset speaker or microphone may be faulty
Replace the phone — if the echo only occurs on one specific phone, it may have a hardware fault
Replace the ATA — if using an analogue adapter, try a different model

Step 6: Check the Other End

Remember that echo is often caused by the remote party's equipment, not yours. If you hear echo of your own voice, the problem is likely on the other person's end. If they are using a speakerphone or a mobile phone in a noisy environment, there may be little you can do other than ask them to use a headset or reduce their volume.

When to Contact Your Provider

If echo occurs consistently on calls to specific number ranges (e.g. all calls to landlines), it may be a hybrid echo issue at your provider's PSTN gateway. Contact your provider with details of affected calls so they can investigate their gateway configuration. Get in touch with our team if you need assistance.