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.

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

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

Introduction (cont’d)

Waveform Substitution

Waveform Substitution (Method A)

Method A (cont’d)

Waveform Substitution (Method B)

Method B (cont’d)

Waveform Substitution (cont’d)

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

Experimental Results (cont’d)

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

Experimental Results (cont’d)

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