– Appliance manufacturers (vacuum cleaners, bathroom exhaust fans) rate noise in sones because consumers understand linear loudness. A 4-sone fan is twice as loud as a 2-sone fan.
| Feature | Phon | Sone | |--------|------|------| | Scale type | Logarithmic (like dB) | Linear | | Zero point | 0 phons (hearing threshold at 1 kHz) | 1 sone = 40 phons | | Doubling meaning | Not applicable | 2 sones = twice as loud | | Best for | Comparing loudness across frequencies | Quantifying how much louder one sound is over another | | Example use | "This 80 Hz tone is 70 phons." | "This fan is 4 sones — twice as loud as that 2-sone fan." | phons and sones