Interlacing properties of line spectrum pair frequencies
Hong Kook Kim, Hwang Soo Lee · IEEE Transactions on Speech and Audio Processing · 1999
An interlacing property of the line spectrum pair frequency (LSF) is proved on the basis of the logarithmic spectral difference function defined by the autoregressive models of successive orders. The property that the LSFs of an order are interlaced with those of lower order, provides a tight bound on the formant frequency region.