Conventional Speaker Identification (SI) systems utilise spectral features like Mel-Frequency Cepstral Coefficients (MFCC) or PerceptualLinear Prediction (PLP) as a frontend module. Line Spectral pairs Frequencies (LSF) are popular alternative representation of Linear Prediction Coefficients (LPC). In this paper, an investigation is carried out to extract LSF from perceptually modified speech. A new feature set extracted from the residual signal is also proposed. SI system based on this residual feature containing complementary information to spectral characteristics, when fused with the conventional spectral feature based system as well as the proposed perceptually modified LSF, shows improved performance.Keywords: SI; speaker identification; LSF; line spectral pairs frequencies; perceptual linear prediction; residual signal; higher order statistics.Reference to this paper should be made as follows: Sahidullah, M., Chakroborty, S. and Saha, G. (2010)