Why Do My Conference Calls Sound Bad?

Problem 1: Echo and Reverberation

What remote participants experience: Speech sounds harsh, hollow, or like it's in a bathroom. Words blur together. Long meetings become fatiguing.

What's happening: Sound from the speaker bounces off hard surfaces (glass walls, bare ceilings, hard floors, whiteboards) and returns to the microphone with a slight delay. This reflected sound mixes with direct speech, degrading clarity.

The technical measure: Acousticians measure this as RT60 - the time it takes for sound to decay by 60 decibels. For most conference rooms, you want RT60 around 0.4-0.6 seconds; larger rooms can be higher. Above 0.8 seconds, remote participants will struggle to follow conversations.

Common causes

• Glass walls: Glass is highly reflective. Rooms with glass on multiple sides are almost always echoey.
• Hard ceilings: Exposed concrete, drywall, or metal ceilings reflect sound directly back down.
• Bare floors: Hard floors (tile, concrete, hardwood) reflect sound. Carpet helps significantly.
• Minimal furniture: Empty rooms echo more. Tables, chairs, and people absorb sound.
• High ceilings: More air volume means longer decay time.

How to fix it

Add soft, sound-absorbing materials to the room. The most effective placements are:

• Acoustic panels on the wall directly behind where people sit
• Ceiling panels or "clouds" above the table
• Heavy curtains or blinds on glass walls
• A rug under the conference table

Learn more about conference room echo

Problem 2: Background Noise

What remote participants experience: Constant hum, rumble, or hiss underneath speech. They have to turn up volume to hear, which amplifies the noise. Straining to listen causes fatigue.

What's happening: The microphone picks up ambient sounds along with speech. Remote participants hear everything the mic hears - they can't filter it out like people in the room can.

The technical measure: Background noise is measured in decibels (dB SPL, with a calibrated meter). A good meeting room should have a noise floor below 40 dB SPL. Above 45 dB SPL, noise starts competing with speech.

Common sources

• HVAC systems: Air handling creates constant low-frequency rumble. Often the biggest culprit.
• Hallway traffic: Conversations, footsteps, and doors from outside the room.
• Electronic equipment: Projectors, displays, and computers with fans.
• External noise: Traffic, construction, airplanes (especially in rooms with windows).
• Refrigerators or vending machines: Surprisingly common in break room conversions.

How to fix it

• HVAC: Adjust airflow during important calls, add duct silencers, or seal gaps around vents.
• Hallway noise: Add door sweeps, weatherstripping, or consider solid-core doors.
• Equipment: Move noisy equipment outside the room or use quieter models.
• Windows: Heavy curtains or secondary glazing can reduce external noise.

Learn more about meeting room noise

Problem 3: Microphone Coverage

What remote participants experience: Some people in the room sound clear, others sound distant or muffled. When certain people speak, remote participants miss words or ask them to repeat.

What's happening: Every microphone has a limited pickup range. People beyond that range sound quieter and less clear. This is especially noticeable with speakerphones placed at one end of a long table.

The technical measure: Coverage mapping shows where in the room the microphone can reliably capture speech. A well-designed room should have coverage across all seating positions.

Common causes

• Microphone too far away: A speakerphone at the center of a 6-meter table won't reach the ends.
• Wrong microphone type: Tabletop mics work for small huddle rooms, not 20-person boardrooms.
• Obstructions: Laptop screens, monitors, or people blocking the mic's line of sight.
• Room shape: L-shaped rooms or rooms with alcoves create dead zones.

How to fix it

• Reposition the microphone: Center it relative to where people actually sit.
• Add extension microphones: Many systems support daisy-chained mics for larger tables.
• Limit seating: Don't seat more people than the mic can cover. A 6-person speakerphone shouldn't serve 12 people.
• Consider ceiling microphones: For large rooms, ceiling arrays provide more even coverage.

Learn more about audio coverage mapping

How to Diagnose Your Room

Before spending money on fixes, figure out which problem (or problems) you have:

Quick echo test

Stand in the center of the room and clap your hands sharply once. Listen for the decay:

• Sound dies quickly (under 0.5s): Echo is probably not your main problem.
• Sound lingers noticeably (0.5-1s): Moderate echo - may need some treatment.
• Sound rings or flutters (over 1s): Significant echo - this is likely your primary issue.

Quick noise test

Sit quietly in the room with HVAC running normally. Close your eyes and listen:

• Can you hear the air system? If yes, remote participants definitely can.
• Can you hear hallway conversations? The mic will pick these up.
• Is there a constant hum or buzz? Check for electronic sources.

Quick coverage test

Join a test call and have someone listen remotely while you walk around the room speaking:

• Does your voice stay consistent? Good coverage.
• Do you get quieter in certain spots? Those are coverage dead zones.
• Do you disappear entirely somewhere? The mic has a hard limit there.

When Multiple Problems Combine

Most problem rooms have more than one issue. Here's how to prioritize:

Echo + Noise

Fix echo first. Acoustic treatment that reduces echo often helps with noise too (absorptive materials reduce reflections of noise as well). Also, when echo is reduced, speech becomes clearer relative to the noise floor.

Coverage + Echo

This combination is tricky. Echo can make it seem like the microphone isn't picking up distant speakers, when actually the echo is masking their speech. Fix echo first, then reassess coverage.

Coverage + Noise

If noise is constant (HVAC), fix that first - no amount of better microphone coverage will help if there's constant rumble. If noise is intermittent (hallway traffic), you might get more value from better coverage that lets you close doors.

All three

Start with the quick tests above to identify the worst offender. Usually it's obvious once you know what to listen for. Fix the biggest problem first, then reassess - often fixing one issue reveals that another wasn't as bad as it seemed.