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A Model of Binaural Processing Based on Tree-Structure Filter-Bank. 길이만 , 김영익 , 김화길 , 구임회 한국과학기술원 응용수학전공. Motivation.
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A Model of Binaural Processing Based on Tree-Structure Filter-Bank 길이만, 김영익, 김화길, 구임회 한국과학기술원 응용수학전공
Motivation • Design of auditory preprocessors motivated from the characteristics of biological auditory systems.- robustness to noise- capturing the minute differences between signals (2 Hz difference)- wide dynamic range (140 dB)- selective attention- source localization using two ears
Design of Basilar Membrane (BM) Types of BM Models • Lyon and Mead - R. F. Lyon and C. Mead, An Analog Electronic Cochlea, IEEE Transactions on Acoustics, Speech and Signal Processing, 37(7), 1988. • Liu - W. Liu, A. G. Andreou, and Jr. M. H. Goldstein, Voiced-Speech Representation by an Analog Silicon Model of the Auditory Periphery, IEEE Transactions on Neural Network, 3(3), 1992. • Kates - J. M. Kates, A Time-Domain Digital Cochlear Model, IEEE Transaction on Signal Processing, 39(12), 1991. • Hamming BPF - O. Ghitza, Robustness against Noise: the Role of Timing-Synchrony Measurement. IEEE International Conference on Acoustics, Speech and Audio Processing, 6.8, 1987.
L H L L L L L L L L L L L L L L L H H H H H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H L L L L L L L L H H H H H L L L H H H H H H H H H L H • Design of Filter Bank (2) Fully Cascaded BPF (3) TSFB (1) Lyon & Mead • Cascaded LPFs • Number of Filters: • Cascaded LPFs & HPFs • Higher bandpass capability • Equal delay time • Number of Filters: • Tree sructure • Cascaded LPFs & HPF • Higher bandpass capability • Equal delay time • Versatile Q control • Number of Filters:
Binaural Processing Models • EE (Excitation-Excitation) cells in medial superior olive (MSO)- interaural cross-correlation models • EI (Excitation-Inhibition) cells in lateral superior olive (LSO) - equalization-cancellation (EC) theory
Interaural Cross-correlation Model (EE-type cells) • Running interaural cross-correlation (Jeffress, 1948) • Delay weighting (Colburn, 1977) • Frequency weighting (Stern and Shear, 1996)
Lindemann’s Model (EI-type cells) • Contralateral inhibition mechanism • Stationary-inhibition component • Dynamic-inhibition component
Breebaart Model (EI-type cells) • EI-type cell • Combined EI-type cell • Temporal windowing • Nonlinear saturation
Shamma’s Model The Stereausis Network
Network output for time shifted 600Hz tonea) zero shift b) shift c) shift d) shift
Simulation for Binaural Processing - Signal : TI46 (‘zero’ ~ ‘nine’) male speech samples - Noise : Noisex samples
Conclusion • A model of binaural processing with TSFB has been suggested. • Simulation results showed that the binaural processing could be advantageous in noisy environment. • The HRTF could degrade the performance of speech recognition. • A new feature combining binaural data will be investigated in the sense of noise robustness.