L&L Therapy Services, LLC

This tutorial reviews acoustic methods that have been used to characterize vocal function. The most persuasive argument for the use of acoustic measures is that all of the information used by listeners to make judgments about speech is to be found in the acoustic signal. Acoustic methods have been used clinically to differentiate normal from abnormal voices, to aid in differential diagnosis, to evaluate the relative effectiveness of different treatment approaches, and to track progress in voice therapy. The measures discussed here focus on quantifying the degree of periodicity, the shape of the spectrum, and the range of vocal intensity.

Spectral moment analysis (SMA) is an acoustic analysis tool that shows promise for enhancing our understanding of normal and disordered speech production. It can augment auditory-perceptual analysis used to investigate differences across speakers and groups and can provide unique information regarding specific aspects of the speech signal.

The purpose of this paper is to illustrate the utility of SMA as a clinical measure for both clinical speech production assessment and research applications documenting speech outcome measurements. Although acoustic analysis has become more readily available and accessible, clinicians need training with, and exposure to, acoustic analysis methods in order to integrate them into traditional methods used to assess speech production.