What is Audio Coverage Mapping?

Why Coverage Matters for Hybrid Meetings

Every microphone has a limited pickup range. The marketing might say "up to 6 meters," but real-world performance depends on:

• Room acoustics (echo masks distant speech)
• Background noise (competes with quiet voices)
• Microphone placement (obstructions, angle)
• Speaking volume (not everyone projects)

The result: People sitting close to the mic sound clear. People at the edges sound quiet, muffled, or disappear entirely. Remote participants hear some colleagues well and others poorly - which creates an unequal experience and drives complaints.

The problem is that people in the room don't notice. They can hear each other fine. It's only the remote participants who suffer - and they often don't speak up because they assume it's their connection or equipment.

Common symptoms of poor coverage

• "Can you repeat that?" - especially for people at the far end of the table
• Remote participants disengage or stop contributing
• Complaints about "bad audio" that disappear when the room is less full
• Audio quality varies depending on who's speaking

How Coverage Mapping Works

The basic principle

1. Play known audio through the room's speaker system (or from a phone).
2. Record what the microphone captures as you move around the room.
3. Compare the recording to the original at each position.
4. Map the results to show where quality is good vs. degraded.

The comparison typically looks at:

• Level: How loud is the captured audio relative to the source? Quieter = worse coverage.
• Frequency response: Are speech frequencies (mid-range) preserved? Muffled speech suggests poor coverage.
• Dropouts: Are there moments where audio disappears entirely?

Manual coverage testing

You can test coverage without special tools:

1. Join a video call with a colleague listening remotely.
2. Walk around the room while counting aloud or reading text.
3. Ask your colleague to note where audio quality changes.
4. Mark problem areas on a floor plan.

This gives qualitative results ("the back corner is bad") but not precise measurements.

What Coverage Maps Show

The heatmap

A coverage map typically uses color to indicate audio quality at each position:

• Green: Good coverage. Speech captured clearly.
• Yellow: Marginal coverage. Speech captured but may be quiet or slightly degraded.
• Orange/Red: Poor coverage. Speech is muffled, quiet, or intermittent.
• Gray/Uncolored: Not tested (didn't walk there).

Key metrics

Coverage percentage: What portion of the tested area has acceptable audio quality. Aim for 70-80%+ of the seating area (higher for critical rooms).

Effective pickup radius: The distance from the microphone where audio quality stays acceptable. Useful for understanding how many seats are covered.

Dropout rate: The percentage of samples where audio dropped out entirely. High dropout means unreliable coverage - words will be missed.

Level attenuation: How much quieter captured audio is compared to the source. More attenuation means the mic is working harder to pick up sound.

Interpreting results

Good coverage map: Mostly green across all seating positions. Effective radius covers the whole table. Dropout rate under 10%.

Problematic coverage map: Green near the mic, yellow/red at the edges. Effective radius doesn't reach far seats. Dropout rate over 15%.

Equipment vs. acoustics:

• If coverage is poor but acoustics are fine (low RT60), the problem is the equipment or its placement.
• If coverage is poor and acoustics are also poor (high RT60), echo is masking distant speech. Fix the acoustics first.

What's Good Coverage?

Dropout rate guidelines

• Under 10%: Reliable coverage. Occasional dropouts but speech is mostly captured.
• 10-20%: Some words will be missed. Remote participants may need repetition.
• Over 20%: Frequent dropouts. Unreliable for important conversations.

Context matters

What counts as "good" depends on how the room is used:

• Executive boardroom: Aim for 90%+ coverage. Every seat matters.
• Large training room: 75%+ may be acceptable if the presenter area is well-covered.
• Huddle room: Small rooms should have 85%+ - if they don't, something's wrong.

Improving Coverage

Quick fixes (no equipment purchase)

Reposition the microphone: Center it relative to where people actually sit, not where it looks neat. A few inches can make a difference.

Remove obstructions: Laptop screens, monitors, and decorative items between speakers and the mic block sound.

Limit seating: Don't seat more people than the mic can cover. A "6-person" room with a tabletop speakerphone shouldn't host 12 people.

Ask people to project: Temporary fix, but awareness helps. "The mic doesn't reach the back row well - can everyone speak up?"

Equipment improvements

Extension microphones: Many speakerphone systems support additional mics that daisy-chain together. Adding one or two can cover a long table.

Better microphone placement: A single mic in the center of a round table outperforms one at the end of a rectangular table.

Ceiling microphones: For larger rooms, ceiling-mounted microphone arrays provide more even coverage than tabletop units. More expensive but effective.

Beamforming technology: Some modern mics use beamforming to focus on active speakers. Can extend effective range in good acoustic conditions.

Acoustic improvements

If coverage is poor because echo masks distant speech, no amount of equipment will fully solve it. Treating the room acoustics improves coverage by making speech clearer at all distances.