EXP 10: SIGNAL PROCESSING APPLICATION

The given experiment is a Group Experiment performed by Umesh Gawale, Tejashree Gore, Pranav Ghaisas and Natasha Choudhary.

Our applications was based on Comb filters.
Patent Review :
Speech Signal Processor using Comb Filter

Application No.: 792,405
Patent No. : US4099030
Inventors : Yoshimutsu Hirata, No. 10-307, 842, Arai, Hino, Tokyo, Japan
Publication : 4^th July, 1978
Summary : Disruptive discontinuities resulting from sampling in a time compression and expansion FT system are minimized by use of comb filters.

https://drive.google.com/open?id=0ByBqyA3dBdX7T3ROQ3VXRy04Vnc

IEEE Paper Review:
Speech Enhancement Using Harmonic Emphasis and Adaptive Comb Filtering
Publisher : Wen Jin, Xin Liu, Michael S. Scordilis and Lu Han
Summary :
An enhancement method for single-channel speech degraded by additive noise is proposed. A spectral weighting function is derived by constrained optimization to suppress noise in the frequency domain. Two design parameters are included in the suppression gain. Further enhancement of the harmonics is achieved by adaptive comb filtering derived using the gain factor with a peak-picking algorithm. The performance of the enhancement method was evaluated by the modified bark spectral distance, composite objective measures and listening tests. Experimental results indicate that the proposed method outperforms spectral subtraction; a main signal subspace method applicable to both white and colored noise conditions and a perceptually based enhancement method with a constant noise-flooring parameter, particularly at lower signal-to-noise ratio conditions. Our listening test indicated that 16 listeners on average preferred the proposed approach over any of the other three approaches about 73% of the time.

https://drive.google.com/open?id=0ByBqyA3dBdX7RTVZcVJQMVlqN00