Significance of epoch identification accuracy for prosody modification

Epoch refers to instant of significant excitation in speech [1]. Prosody modification is the process of manipulating the pitch and duration of speech by fixed or dynamic modification factors. In epoch based prosody modification, the prosodic features of the speech signal are modified by anchoring around the epochs location in speech. The objective of the present work is to demonstrate the significance of epoch identification accuracy for prosody modification. Epoch identification accuracy is defined as standard deviation of identification timing error between estimated epochs with the reference epochs. Initially, the epochs location of the original speech are randomly varied for arbitrary time factors and corresponding prosody modified speech is generated. The perceptual quality of the prosody modified speech is evaluated from the mean opinion scores (MOS) and objective measure. The issues in the prosody modification of telephonic speech signals are also presented.