Audio
RT60
Also called: reverberation time, decay time
The time in seconds for sound in a room to decay by 60 dB — the standard measure of how reverberant a space is and how intelligible speech will be in it.
Speech-focused rooms want a short RT60, roughly 0.4–0.6 seconds. Glass walls, hard ceilings, and stone floors push it far past that, which is why so many beautiful modern conference rooms sound terrible on calls. High RT60 smears consonants, which is exactly what listeners need to distinguish words.
Reverberation is a construction property, so it is solved with materials: acoustic panels, baffles, carpet, or an acoustically absorptive ceiling tile. We measure RT60 during site survey and flag it in writing early, because absorption added during fit-out is inexpensive while absorption added after handover is a change order and a disruption.
Related terms
- NC Rating
- A single-number rating of a room's background noise level across frequency bands, used to judge whether mechanical noise will interfere with speech and conferencing.
- AEC
- Processing that subtracts the room's own loudspeaker output from the microphone signal so remote participants do not hear their own voices echoed back.
- Wi-Fi Site Survey
- Measurement and modelling of wireless coverage, interference, and capacity in a specific building to determine access point count, placement, and channel plan.
More Audio terms
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