This formula provides the approximate sound pressure level in dBA corresponding to a given perceived loudness in sones .
Another consideration: the initial question might have a typo. Instead of "sone to dba verified", maybe they meant "sone to dba verified", but I think the key is to address converting between loudness (sones) and sound pressure levels (dB/dB(A)), and how to verify the accuracy of such conversions.
The formula above works strictly for free-field pure tones. For real-world appliances, use this verified regression formula (from AMCA Standard 301): sone to dba verified
Phons measure loudness level, while sones measure loudness perception. The relationship is: 1 sone = 40 phons . The phon scale aligns with dB (logarithmic), while the sone scale is linear. Doubling the sone value doubles perceived loudness, which corresponds to approximately a 10 phon (or 10 dB at 1 kHz) increase .
(33.2 * 0) + 34 =
1 sone
If you skip verification, you will fall into these traps: This formula provides the approximate sound pressure level
Look up generic chart: 1.5 Sones ≈ 30 dBA. Write spec. Fail.
When in doubt, rent a sound meter. The cost of a meter is lower than the cost of buying the wrong exhaust fan—or failing an OSHA noise compliance audit. The formula above works strictly for free-field pure tones
These different testing geometries and rounding rules mean that two products with the same laboratory rating might measure differently in actual room conditions.
are linear; 2.0 sones is perceived as exactly twice as loud as 1.0 sone.
