(Coined in a 1963 paper by Bogert, Healey, and Tukey) The Fourier transfORm of the log-magnitude spectrum: fFt(ln( | fFt(window . signal) | )) This function is used in speech recognition and possibly elsewhere. Note that the outer transfORm is NOT an inverse Fourier transfORm (as repORted in many respectable DSP texts). [What' s it fOR?] (1997-01-07)