How to Improve Audio Quality on VoIP Calls

Internet-based calling has made business calls more flexible and affordable, but it also means call quality depends on networks, devices, and settings. Choppy audio, echo, delays, robotic-sounding voices, and dropped calls are common complaints. The good news is that most VoIP audio problems can be diagnosed and fixed.

This guide explains how to identify the cause of poor audio and the practical steps that improve it.

Step 1: Identify the Problem

Different symptoms usually point to different causes.

Step 2: Find Out Where the Problem Is

Before fixing anything, narrow down where the problem happens:

• Is it every call, or only some? Problems on all calls suggest a local issue, while problems on some calls may relate to particular destinations or times.
• Is it only certain people? If only one person has problems, the cause is likely their device, connection, or environment.
• Is it at certain times? Problems during busy periods may point to network congestion.
• Who hears the problem? If the other person hears you badly but you hear them fine, the problem is likely with your microphone or upload connection.

Many phone systems provide call quality reports, showing measures such as latency, jitter, packet loss, and a Mean Opinion Score (MOS), which rates call quality from 1 (bad) to 5 (excellent). These reports can point directly to the cause.

Step 3: Check Your Internet Connection

Most VoIP problems come back to the internet connection.

Use a wired connection

Wired Ethernet connections are generally more stable than Wi-Fi, which can suffer from interference, distance from the router, and congestion. If you must use Wi-Fi, stay close to the router and use a less congested frequency band if available.

Test your speed and stability

Run an internet speed test, paying attention to upload speed, latency, and jitter, not just download speed. VoIP needs stable upload speeds as well as download.

Check bandwidth

Each call needs a certain amount of bandwidth, often around 100 kilobits per second in each direction for standard audio, including overhead. Multiply this by the number of simultaneous calls, and make sure there's capacity to spare alongside other internet use.

Reduce competing traffic

Large downloads, video streaming, cloud backups, and software updates can compete with calls for bandwidth. Schedule heavy activities outside calling hours or limit them during calls.

Step 4: Adjust Network Settings

Enable quality of service (QoS)

Quality of service settings on routers and network equipment let you give voice traffic priority over other data, so calls stay clear even when the network is busy.

Check SIP ALG

Many routers include a feature called SIP ALG (application layer gateway), intended to help VoIP traffic pass through. In practice, it often causes problems such as one-way audio or dropped calls. Many VoIP providers recommend turning it off. Check your provider's guidance.

Check firewall settings

Firewalls can block or interfere with call audio. Your provider can tell you which ports and settings need to be allowed.

Separate voice traffic

In larger offices, putting voice traffic on its own network segment, often called a voice VLAN, can improve reliability.

Upgrade old equipment

Older routers may struggle with modern traffic loads. Upgrading can make a noticeable difference.

Step 5: Avoid Unnecessary Routing

Sending calls through a VPN or security system located far away can add delay and reduce quality. If calls must use a VPN, check whether voice traffic can be routed more directly. Also check that your provider has servers reasonably close to you.

Step 6: Check Your Device and Software

• Restart the computer or phone if problems appear after long use.
• Update softphone apps, operating systems, and headset software.
• Close unnecessary applications, especially those using lots of processing power or bandwidth.
• Check audio settings, making sure the correct microphone and speaker are selected.
• Update desk phone firmware, if using IP phones.

Step 7: Improve Your Headset and Microphone Setup

Use a good headset

Built-in laptop microphones and speakers often cause echo and pick up background noise. A good headset with a noise-cancelling microphone makes a significant difference.

Position the microphone correctly

For boom microphones, position the microphone near the corner of your mouth, roughly two finger-widths away, and avoid breathing directly into it.

Prefer wired headsets for reliability

Bluetooth headsets can sometimes add delay or reduce audio quality. If you experience problems, try a wired headset.

Step 8: Reduce Echo

Echo often happens when sound from a speaker is picked up by a microphone and sent back. To reduce it:

• Use a headset rather than speakerphone.
• Lower speaker volume if using speakers.
• Check headset fit, so sound doesn't leak into the microphone.
• Update softphone software, which often includes echo cancellation.

Step 9: Control Your Environment

• Work in a quiet space where possible.
• Close doors and windows to reduce outside noise.
• Use soft furnishings, such as rugs and curtains, to reduce room echo.
• Mute when not speaking in noisy settings.

Step 10: Review Codec Settings

A codec compresses voice for transmission. Some codecs use less bandwidth but reduce quality, while others offer better quality but need more bandwidth. Modern codecs such as Opus adjust to network conditions. If you have control over codec settings, your provider can advise on the best choice for your connection.

Step 11: Work With Your Provider

If problems continue:

• Check your provider's status page for known issues.
• Use provider testing tools, if available.
• Share call quality reports with support, including dates, times, and numbers affected.
• Ask about their network routing and server locations.

A Quick Troubleshooting Checklist

• Use a wired internet connection.
• Test upload speed, latency, and jitter.
• Reduce bandwidth-heavy activity during calls.
• Enable QoS on your router.
• Check SIP ALG and firewall settings.
• Avoid routing calls through distant VPNs.
• Update software and firmware.
• Use a good-quality headset.
• Reduce background noise and echo.
• Contact your provider with specific details.

Clear Calls by Design

Poor audio quality makes every call harder, frustrating customers and staff alike. But most VoIP problems have identifiable causes, whether it's a weak Wi-Fi signal, an overloaded network, a router setting, or a poor headset. By diagnosing problems carefully and working through these steps, most businesses can achieve clear, reliable calls that let conversations flow naturally.

Related articles

• What Is a Session Border Controller?