Manufacturers often prefer Sones for consumer products because:
Both the 50 dB tone (100 Hz) and 92 dB tone (20 Hz) can be expressed as 1 sone or 40 phons. SIEMENS Community DB Concepts | PDF | Decibel | Ear - Scribd sone to dba
Where:
For (not pure tones):
Sound Quality Metrics: Loudness and Sones - SIEMENS Community sone to dba