Acoustic Analysis of Breathy and Rough Voice Characterizing Elderly Speech

Abstract

This paper aims at investigating acoustic features, which can objectively explain breathiness and roughness of elderly speech, respectively. In this paper, acoustic analysis was carried out using word sequences, which were uttered by 153 male speakers in the age range of between 20 and 89 years old. Concerning the breathiness, we confirmed that elderly breathy voices caused energy lift in higher frequency region over 4 kHz in average power spectra during the stationary parts in the uttered vowels. Concerning roughness, we observed the slight fluctuations, which synchronized with vocal cord vibration, in amplitude spectra during stationary parts of vowels. Based on acoustic analysis results, we propose physical parameters for measuring breathiness and roughness, respectively. In this paper, listening tests were carried out to quantitatively give the subject degrees of breathiness and roughness, respectively. It was confirmed that the proposed physical parameters had correlation with each of subjective degrees. Relationships between age and acoustic characteristics of breathiness and roughness were investigated using the proposed parameters. It is confirmed that the degree of breathiness and roughness increased in proportion to age, especially in age ranges over 60 years old.