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World’s Quietest Room: Current Record and Measurement
The current Guinness record for the quietest place is held by the anechoic test chamber at Orfield Laboratories in Minneapolis. Guinness reports a −24.9 dBA measurement from November 19, 2021. Microsoft’s Building 87 chamber remains a landmark engineering facility and held the previous record at −20.35 dBA in 2015.
This page tracks the measurement record. It does not rank visitor endurance, claim that one chamber is “best” for every acoustic task, or turn an engineering measurement into a psychological promise.
Key takeaways
- Guinness currently lists Orfield Laboratories at −24.9 dBA.
- Microsoft’s chamber held an earlier Guinness record at −20.35 dBA.
- Negative decibels are possible because zero dB is a reference, not absolute silence.
- A chamber’s background level, usable frequency range, size, and test purpose are separate specifications.
- Record claims should always name the source, weighting, measurement date, and facility.
The current quietest-place record
Guinness World Records identifies the anechoic test chamber at Orfield Laboratories as the record holder. The listed result is −24.9 decibels A-weighted, measured in Minneapolis in 2021.
The date matters. Many otherwise accurate articles still repeat Microsoft’s 2015 record because they cite a historical announcement without checking the current record page. Microsoft did set a real record; it is now a former record.
How an extremely quiet chamber is measured
An acoustic anechoic chamber is designed to isolate outside noise and absorb reflections inside. Guinness describes Orfield’s nested construction, vibration-isolating springs, heavy insulation, fiberglass wedges, and suspended mesh floor.
At levels this low, the self-noise of measurement equipment becomes a challenge. Guinness says the 2021 result used two microphone channels and cross-correlation: electrical noise differed between the channels, while the room signal common to both could be identified.
A record value should therefore be read with its method. “Quietest” is not a casual phone reading, and two facilities should not be compared from numbers recorded with unknown weighting, bandwidth, calibration, location, and uncertainty.
What negative decibels mean
Decibels express a ratio to a reference level. For airborne sound-pressure measurements, zero dB does not mean there is no sound; it represents a defined reference pressure. A negative value means the measured pressure is below that reference.
The weighting also matters. Guinness reports the record in dBA, which applies an A-weighting intended to approximate aspects of human hearing sensitivity. A dBA result should not be silently relabeled as an unweighted dB SPL result.
Orfield and Microsoft: two important chambers
| Facility | Documented record result | Record context | Primary purpose described |
|---|---|---|---|
| Orfield Laboratories | −24.9 dBA | Current Guinness listing; measured in 2021 | Acoustic testing, research, consultation, and arranged visitor sessions |
| Microsoft Building 87 | −20.35 dBA | Guinness record announced in 2015 | Audio, device, and product engineering |
These values document record history, not a complete capability ranking. Chamber dimensions, low-frequency performance, test setup, equipment, and intended use can matter more than the headline background level for a particular project.
How to check a “world’s quietest” claim
- Open the current record-body page, not only an old announcement.
- Record the facility, date, value, weighting, and measurement description.
- Distinguish current holder, former holder, and a facility’s own marketing language.
- Check whether the comparison uses the same metric and conditions.
- Keep acoustic performance separate from visitor experience or endurance myths.
For research on reported perceptions, see what sensory-deprivation studies actually show. For the viral prize story, see our $5 million challenge fact check.
Frequently asked questions
Who holds the current Guinness record?
Guinness currently lists Orfield Laboratories in Minneapolis, with a −24.9 dBA result measured in 2021.
Was Microsoft’s record fake?
No. Guinness documented Microsoft’s −20.35 dBA record in 2015. It is an important former record, not the current listing.
Is the room absolutely silent?
No measurement proves the total absence of sound. The record describes a very low measured background level under stated conditions.
How can a sound level be below zero?
Because decibels are relative to a reference. Below zero means below that reference level, not “less than no sound.”
Can people visit the current record holder?
Orfield’s current visitor page advertises by-appointment tours and silent sessions. Confirm availability and terms directly before making plans.
References
