Dear list, I am unable to get books from Zwicker, Terhardt and other relevant books about psychoacoustics. So I can not check one thing: Frequency spreading used in ITU-R BS.1387 is based on Terhardt: 24+230/fc+0.2*L db/Bark Is this spreading based on assumption that exact bark scale is used, or is it based on assumption that bark scale aproximation by Terhardt is used? Please help.