The objective of this work is to analyze the effect of emotions on the excitation source of speech production. The neutral, angry, happy, boredom and fear emotions are considered for the study. Initially the electroglottogram (EGG) and its derivative signals are compared across different emotions. The mean, standard deviation and contour of instantaneous pitch, and strength of excitation parameters are derived by processing the derivative of the EGG and also speech using zero-frequency filtering (ZFF) approach. The comparative study of these features across different emotions reveals that the effect of emotions on the excitation source is distinct and significant. The comparative study of the parameters from the derivative of EGG and speech waveform indicate that both cases have the same trend and range, inferring any of them may be used. Use of the computed parameters are found to be effective in the prosodic modification task. © 2010 ISCA.