Qualitative acoustic analysis in the study of motor speech disorders

Traditional measurements performed on the acoustic signals of normal speech are frequently used to quantify the acoustic characteristics of disordered speech as well. This letter demonstrates how important aspects of speech production deficits in motor speech disorders may be overlooked if stringent quantification procedures are employed, especially in the stage of exploratory data analysis. It is suggested that qualitative procedures, wherein phenomena are inferred from visual examination of certain acoustic displays, are useful to supplement traditional measurements, and moreover, that they be used to point to the types of measurements that should be made in the finer-grained stages of quantitative analysis.