Because the scale is linear, the math is simple for consumers. If a fan is rated at 3 sones, you know it will be three times louder than the baseline quiet hum of 1 sone.
[dB , SPL \approx 33.2 + 20 \log_10(\textsone)] sones to db
| Sones | Approx. Decibels (dB) | Perceived Loudness | Example | | :--- | :--- | :--- | :--- | | | 40 dB | Baseline Quiet | Quiet Refrigerator | | 1.5 | 41.8 dB | Very Quiet | High-end Range Hood | | 2.0 | 43 dB | Quiet | Soft Whisper | | 3.0 | 44.8 dB | Noticeable | Quiet Office | | 4.0 | 46 dB | Moderate | Quiet Conversation | | 5.0 | 47 dB | Moderate | Dishwasher in next room | | 6.0 | 47.8 dB | Moderately Loud | Normal Conversation | | 8.0 | 49 dB | Loud | Garbage Disposal (low setting) | | 10.0 | 50 dB | Loud | Light Traffic | Because the scale is linear, the math is
The conversion from sones to dB SPL (Sound Pressure Level) isn't straightforward because sones measure perceived loudness, while dB SPL measures sound pressure level. However, there's an approximate relationship that can be used for conversion. Decibels (dB) | Perceived Loudness | Example |