The paper deals with a proposal of original E-model
modification, the new model includes improvements giving more
precise results when a jitter is present in transmission channel. Our
idea is based on the fact that the network jitter can affect overall
delay in delivery or a packet loss due to a limitation of play-out
buffer in IP phones or VoIP gateways. Delay is incorporated in an
impairment factor Id of E-model whereas losses are issue of Ie-eff
parameter. We examined how the estimated speech quality is affected
by jitter and compared computed results with MOS values gained by
PESQ objective intrusive method (Perceptual Evaluation of Speech
Quality). Experiments were performed in circumstances of varying
delay, packet loss, jitter and play-out buffer. We have proved that the
proposed modification improves estimated MOS computed by Emodel.Scopus7324824
