1. Recovery of Missing Speech Packets Using the Short-Time Energy and Zero Crossing Measurements Nurgun Erdol, IEEE, Claude Castelluccia, and Ali Zilouchian, Senior Member, IEEE Hung, Kuo-EnNTHU/CS, Visual Communication Lab.

2. Outline Introduction Waveform Substitution Based on the STE and the Zero-Crossing Information Experimental Results Analysis and Evaluation of the Reconstruction methods Conclusions

3. Introduction Short-time energy (STE) Zero-crossing Rate (STZR) Zero-crossing Locations (STZL)

4. Introduction (cont’d)

5. Waveform Substitution

6. Waveform Substitution (Method A)

7. Method A (cont’d)

8. Waveform Substitution (Method B)

9. Method B (cont’d)

10. Waveform Substitution (cont’d)

11. Experimental Results Parameters (a)Packet loss rate (b)Packet length (c)STE window length (d)Interpolation technique

12. Experimental Results (cont’d)

19. :Method A  : Method B  : Zero-stuffing

20. Experimental Results (cont’d)

22. Conclusions STE and STZL’s of a speech segment in a packet are sufficient parameters for reconstruction. Method A can be used until the packet loss rate get up to 40% Provide a smooth transition in energy