Smeared FFT representation of harmonic lines in case of changing pitch.
To replace the harmonics in the Fourier transform with Chirps.
Replacement of the harmonics in Fourier trf by properly designed chirps provide a new orthogonal transform, which over-performs Fourier significantly in cases like mentioned above. The gain we get in enhanced T-F representation could be well used for speech enhancement and other methods, as discussed in our papers.
 Weruaga, L. and Képesi, M: “Speech analysis with the Short-time Chirp transform”, 8th European Conf. on Speech , EUROSPEECH 2003, Geneva, Sept 2003, vol.I, pp.53-56.
 Képesi, M. Weruaga, L.: “Speech Analysis with the Fast Chirp Transform, ” EUSIPCO 2004, the 12th European Signal Processing Conference, Wien, Austria, 7-10 September 2004
 Weruaga, L. and Képesi, M.: “EM-driven Stereo-like Gaussian Chirplet Mixture Estimation”, ICASSP 2005, IEEE International Conference on Acoustics, Speech, and Signal Processing. March 1923, IV, pp. 473-476, 2005, Philadelphia, USA.
 L. Weruaga and M. Képesi, “Self-organizing chirp-sensitive artificial auditory cortical model,” Interspeech 2005, pp. 705-708, Lisboa (P), Sep. 2005.
 M. Képesi, L. Weruaga, “Adaptive chirp-based time-frequency analysis of speech signals”, Speech Comm., vol.48, pp. 474-492, 2006.
 L. Weruaga, M. Képesi, “The fan-chirp transform for non-stationary harmonic sounds”, Signal Proc., vol. 87, pp. 1504-1522, 2007.
 R Dunn, TF Quatieri, “Sinewave Analysis/Synthesis Based on the Fan-Chirp Tranform,” IEEE Workshop on Applications of Signal Processing to …, 2007
 Macej Bartkowiak, “Application of the Fan-Chirp Transform to Hybrid Sinusoidal+Noise Modeling of Polyphonic Audio,” Eusipco 2008, Lausanne, Switzerland
 Pei Zhao; Zhiping Zhang; Xihong Wu, “Monaural speech separation based on multi-scale Fan-Chirp Transform,” Acoustics, Speech and Signal Processing, 2008. ICASSP 2008, March 31 2008-April 4 2008 Page(s):161 – 164
 Ha Nguyen, Luis Weruaga: “Time–Frequency Analysis of Vietnamese Speech Inspired on Chirp Auditory Selectivity,” Book Series Lecture Notes in Computer Science, pp. 284-295, Springer Berlin / Heidelberg, Volume 5351/2008, 2008,
 “FAN CHIRP TRANSFORM FOR MUSIC REPRESENTATION”, P. Cancela, E. Lopez, M. Rocamora, DAFx 2010.
 Pei Zhao, Zhiping Zhang, Xihong Wu: Monaural speech separation based on multi-scale Fan-Chirp Transform, ICASSP 2008. March 31 2008, Page(s): 161 – 164
 Hui Yin, Climent Nadeu, and Volker Hohmann1: Pitch- and Formant-Based Order Adaptation of the Fractional Fourier Transform and Its Application to Speech Recognition, Hindawi Publishing Corporation, EURASIP Journal on Audio, Speech, and Music Processing Volume 2009, Article ID 304579.