Room background noise targets
How quiet should the room be? Pick the room type, enter what your meter reads with the HVAC running, and compare.
Target
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Approx. target in dBA
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Your room vs. target
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Targets by room type
| Room | NC target | ≈ dBA |
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Typical design targets. NC is measured in octave bands; the dBA figures here use the common rough rule that dBA runs about 5–10 dB above the NC number (7 dB used).
How it works
Noise criteria (NC) curves rate background noise, mostly HVAC, across the octave bands people hear, so a low rumble and a high hiss are judged fairly. The NC rating is the lowest curve the measured noise stays under in every band. A plain dBA reading is easier to take and a reasonable first check, which is what this page uses.
Field notes
- Measure the room as it's used. HVAC on, doors closed, at seated head height, without people talking. Take readings at a few seats.
- Noise sets the floor for everything else. Speech needs to sit well above the background to be understood, so a noisy room needs a louder system, and a louder system means more feedback and echo risk.
- For video meetings, noise travels. HVAC hum the room has stopped noticing is right there for the far end, and noise suppression that fights it costs voice quality.
- Low rumble hides in dBA. A-weighting turns down low frequencies, so a room can read fine in dBA and still rumble. If it sounds boomy, measure in octave bands or dBC.