Subject: Re: frequency to mel formula From: "Richard F. Lyon" <DickLyon@xxxxxxxx> Date: Wed, 15 Jul 2009 23:10:12 -0700 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>It's funny how numbers get around. There's a good summary/survey at Hartmut Traunmüller's page: http://www.ling.su.se/STAFF/hartmut/bark.htm With respect to Beranek 1949 he says: "Ratio pitch m (in mel): m = 1127 ln (1 + f / 700) This is an approximation based on data tabulated by Beranek [8]." but doesn't say who published the approximation. The wikipedia article uses the factor 1127.01048 to get exactly 1000 mel at 1000 Hz. Searching for this number in Google scholar, the earliest source I find for it is in a 2005 paper that acknowledges that it came from wikipedia. Since that time, it appears in many papers. It's another example of unsourced wikipedia information being copied and published, likely to later be sourced to someone who copied it from wikipedia. The number was added to wikipedia in Jan 2003, here: http://en.wikipedia.org/w/index.php?title=Mel_scale&diff=prev&oldid=571444 by this guy in Eindhoven: http://en.wikipedia.org/wiki/User:Ap This page: http://users.utu.fi/jyrtuoma/speech/Mel2Hz.html suggests that the editor may be J.R. de Pijper of IPO (just because he provided the formula and he's in Eindhoven). Since that time the excessively accurate number has crept into a few 2007 and 2008 books: http://books.google.com/books?as_q=1127.01048 I recommend we stick with 1127, though I still don't know where it comes from; does anyone? Give me a source and I'll fix wikipedia... Dick