sone (s?n)n. A subjective unit of loudness, as perceived by a person with normal hearing, equal to the loudness of a pure tone having a frequency of 1,000 hertz at 40 decibels.[Latin sonus, a sound; see swen- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.sone (s??n) n (General Physics) a subjective unit of loudness equal to that experienced by a normal person hearing a 1 kHz tone at 40 dB[C20: from Latin sonus a sound]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014sone (so?n) n. an acoustic unit for measuring loudness, judged equal to the loudness of a 40-decibel, 1-kilohertz reference sound. [1945?50;