SONE
| Date | Clue |
|---|---|
| 2022-04-21 | Acoustic measure |
| 2018-12-27 | Acoustic measure |
| 2017-12-09 | Volume measure |
| 2015-10-31 | Aural measure |
| 2014-10-15 | Unit of loudness |
| 2013-10-18 | Volume measure |
| 2012-08-05 | Loudness unit |
| 2011-05-15 | Loudness unit |
| 2010-01-13 | Loudness unit |
| 2008-03-13 | Loudness unit |
| 2007-11-24 | Loudness unit |
| 2006-12-03 | Loudness measure |
| 2004-12-12 | Unit of volume |
| 2000-06-24 | Sound amount |
| 1998-09-26 | Loudness unit |
| 1997-11-12 | Unit of loudness |
| 1997-10-03 | Loudness unit |
| 1997-07-13 | Loudness measure |
| 1995-11-16 | Sound measure |
| 1994-10-08 | Loudness measure |
| 1994-09-07 | Loudness unit |
| 1994-05-08 | Loudness unit |
| 1994-02-27 | Unit of loudness |