Title :
AM-FM separation using auditory-motivated filters
Author :
Quatieri, T.F. ; Hanna, T.E. ; O´Leary, G.C.
Author_Institution :
Lincoln Lab., MIT, Lexington, MA, USA
Abstract :
A new approach to the joint estimation of sine-wave amplitude modulation (AM) and frequency modulation (FM) is presented based on the transduction of frequency modulation into amplitude modulation by digital filters, being motivated by the hypothesis that the auditory front end uses a similar transduction mechanism in measuring sine-wave FM. An AM-FM estimation algorithm is derived which uses the amplitude envelope of the output of two transduction filters of piecewise-linear spectral shape. The piecewise-linear constraint is then relaxed, allowing a wider class of transduction filters for AM-FM separation. The particular class of Gaussian filters is shown to yield a closed form solution to AM-FM estimation. Solution stability analysis and error evaluation are performed, and the FM transduction method is shown to typically compare favorably with the Teager energy operator and the Hilbert transform for AM-FM estimation. Finally, the amenability of cochlear gammatone-filter pairs to separate AM and FM is demonstrated
Keywords :
amplitude modulation; digital filters; ear; error analysis; filtering theory; frequency modulation; hearing; numerical stability; parameter estimation; piecewise-linear techniques; AM-FM estimation; AM-FM estimation algorithm; AM-FM separation; Gaussian filters; Hilbert transform; Teager energy operator; amplitude envelope; auditory front end; auditory-motivated filters; closed form solution; cochlear gammatone-filter pairs; digital filters; error evaluation; frequency modulation; joint estimation; piecewise-linear constraint; piecewise-linear spectral shape; sine-wave FM measurement; sine-wave amplitude modulation; solution stability analysis; transduction filters; transduction mechanism; Amplitude estimation; Amplitude modulation; Closed-form solution; Digital filters; Frequency estimation; Frequency measurement; Frequency modulation; Piecewise linear techniques; Shape measurement; Spectral shape;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1996. ICASSP-96. Conference Proceedings., 1996 IEEE International Conference on
Conference_Location :
Atlanta, GA
Print_ISBN :
0-7803-3192-3
DOI :
10.1109/ICASSP.1996.543286