Seminar on Voice Quality

1.1 Introduction

The term voice quality is used to describe the quality of sound produced with a particular setting of the vocal folds, including modal phonation that produces a plain or normal voice quality and the non-modal phonation of breathy and creaky voice qualities. Voice quality provides information at multiple levels of linguistic organization, and manifests itself through acoustic cues including F0, and information in spectral and temporal structures. If we can reliably extract acoustic features that differentiate phones that differ from each other regarding voice quality, then such a difference can be modeled in an Automatic Speech Recognition system (ASR) with the goal of improving recognition performance. The acoustic source of voiced speech sounds such as vowels is airflow through the glottis. Quasi- periodic vibration of the vocal folds affects airflow, and can be measured in terms of the volume velocity waveform. The glottal source waveform constitutes an input signal to the vocal tract, which functions as a resonator or a filter that modulates the signal (Fant 1960).

As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.