There seems to be some 10 KHz signal, but it's like -75 dB. I
doubt you
can hear that, since the rest seems to be around -10 dB. I can't
hear it.
You are right I just checked with different headphones, and I don't
hear it with those -- only my sony mdr-7506 do reproduce the
artefact, and trust me, with them it does not sound like a -60dB
noise ! (those headphones are very very sensitive to high frequencies)
For people who may want to check if they hear the difference, I have
put two wav files here
http://gruntthepeon.free.fr/test/m.wav
and
http://gruntthepeon.free.fr/test/m2.wav
they were obtained from the same mp3 file with a "default" and a
"64bit" version of mpg321
Julien
