Indian Journal of Science and Technology

Abstract

Objectives: Harmonic plus Noise Model (HNM) analysis model has been found to be one of the best methods of speech production in terms of important characteristics like naturalness, intelligibility, and pleasantness which are of pre-requisite in any speech synthesiser. Present study explores the approximate percentage of noise required to perceive some phonemes of Hindi language. Method / Analysis: HNM assumes speech as a combination of both periodic and aperiodic signals, so the effect of each part may be individually measured on the quality and intelligibility of different phonemes using HNM. HNM has been employed as the analysis-synthesis platform and the quality of the synthesized speech is tested with the ITU-T standard PESQ measure (perceptual evaluation of speech quality and MOS (mean opinion score). Findings: Objective results suggest that the percentage of the noise serves as a significant constituent in the quality of synthesized speech. Novelty: Investigations suggest that each individual phoneme requires different noise and voice percentage for clear perception. Further, the optimum percentage of the noise part for good speech quality has been found speaker and phoneme dependent.  

Keywords: Analysis-synthesis Models, Speech Processing, HNM, PESQ