Hi, I've looked in various FAQs and web pages for this info, but just can't seem to find it. When two tones of two different frequencies sound equally loud, what's the (rough) relationship between their power? This is for percussive sounds in music, but I assume it's roughly the same for all sounds. The ear seems more sensitive at high frequencies. For example, when you alternate bass drum and high hat, and you adjust them until they both sound about the same, the RMS power of the high hat is a lot smaller than the bass drum. Is the sensitivity roughly 1 / frequency? 1 / sqrt(frequency)? Thanks, Martin --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
It turns out, I found the answer just after I posted the question. There's got to be a version of Murphy's law about this... Anyway, what I was after is called Equal Loudness Curves, and they can be found e.g. here: http://hyperphysics.phy-astr.gsu.edu/hbase/sound/eqloud.html Short version: they're non-linear, and the slope changes with intensity. Thanks, Martin "Martin C. Martin" wrote:> > Hi, > > I've looked in various FAQs and web pages for this info, but just can't > seem to find it. > > When two tones of two different frequencies sound equally loud, what's the > (rough) relationship between their power? This is for percussive sounds > in music, but I assume it's roughly the same for all sounds. The ear > seems more sensitive at high frequencies. For example, when you alternate > bass drum and high hat, and you adjust them until they both sound about > the same, the RMS power of the high hat is a lot smaller than the bass > drum. Is the sensitivity roughly 1 / frequency? 1 / sqrt(frequency)? > > Thanks, > Martin > > --- >8 ---- > List archives: http://www.xiph.org/archives/ > Ogg project homepage: http://www.xiph.org/ogg/ > To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' > containing only the word 'unsubscribe' in the body. No subject is needed. > Unsubscribe messages sent to the list will be ignored/filtered.--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
On Sun 07 Jul 2002 17:58:17, "Martin C. Martin" <martin@metahuman.org> wrote:> I've looked in various FAQs and web pages for this info, but just > can't seem to find it. > > When two tones of two different frequencies sound equally loud, what's > the (rough) relationship between their power? This is for percussive > sounds in music, but I assume it's roughly the same for all sounds. > The ear seems more sensitive at high frequencies. For example, when > you alternate bass drum and high hat, and you adjust them until they > both sound about the same, the RMS power of the high hat is a lot > smaller than the bass drum. Is the sensitivity roughly 1 / > frequency? 1 / sqrt(frequency)?It isn't easily caught in a formulae - I guess we would need ear/brain surgery to find it out exactly... More seriously, this has been measured. You can find a graph and info at http://privatewww.essex.ac.uk/~djmrob/replaygain/equal_loudness.html (from http://www.replaygain.org/ ) The first image is the one you want. Matthijs --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.