1 / 10

Qin Yan Communication & Multimedia Signal Processing Group

Report of Work on Formant Tracking LP Models and Plans on Integration with Harmonic Plus Noise Model. Qin Yan Communication & Multimedia Signal Processing Group Dept of Electronic & Computer Engineering, Brunel University 14 Feb, 2005.

sadah
Download Presentation

Qin Yan Communication & Multimedia Signal Processing Group

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Report of Work on Formant Tracking LP Models and Plans on Integration with Harmonic Plus Noise Model Qin Yan Communication & Multimedia Signal Processing Group Dept of Electronic & Computer Engineering, Brunel University 14 Feb, 2005

  2. Parallel formant synthesizer vs Cascade formant synthesizer MMSE based Pre-cleaning vs LPSS based Pre-cleaning for formant tracking Plan of integration with Harmonic Noise Model (HNM) Outline

  3. System Overview

  4. Parallel Formant Synthesiser I Figure - Klatt synthesizer • Weakness : zeros(troughs) in the overall response of the synthesizer and hard to tuning and control. • Strength : Individual gain Mi for each formant Fi

  5. Iterative optimization process is employed to control the magnitudes of formants. Note: Mi is different from Moi. . Threshold is |Mmodoi– Moi|<0.5dB Parallel Formant Synthesiser II Original Freq Response H Iterative Optimized Freq Response Hmod Original Freq Response H Mmodoi Moi Individual Filter Freq Response Hi Moi Mi

  6. Weakness : only one gain term M for all formants. Hard to adjust magnitude of individual formants. Strength: Overall response is always an all-pole filter even after modifications. No zeros or troughs. Adjustment of magnitudes of individual formant can only be achieved via modification of the bandwidth --- an iterative optimization is required to obtain the required changes between filter parameters. Eg. Decrease Bi Increase Mi ; Increase Bi Decrease Mi. . Cascade Formant Synthesizer with Adjusted Formant Magnitudes Performance of cascade formant synthesizer with adjusted formant magnitude

  7. MMSE based Pre-cleaning I Figure - Performance comparison of LPSS and MMSE on car noisy speech. • MMSE gives better performance in both segmental and global SNR compared with LPSS. • NOTE: In both cases SNR is calculated in FFT domain rather than LP domain.

  8. MMSE based Pre-cleaning II Figure: Average % error of formant tracks of speech in train noise and cleaned speech using spectral subtraction and Kalman filters, the results were averaged over five males. • MMSE is better in all the formants than LPSS. • MMSE+Kalman presents better performance than LPSS+Kalman in lower formants but not in higher formants.

  9. Future Work • Cleaning of the speech excitation --- Using harmonic and noise model (HNM) to model the speech excitation • HNM based clean speech synthesizer. • Pitch tracking in noise conditions. • Maximum voiced frequency estimation. • HNM based speech/excitation enhancement.

  10. Thank You!

More Related