Acoustics of palilalia: A case study

Abstract

Palilalia is a fairly rare speech disorder characterized by repetitions of words, phrases, and/or sentences. The repetitions are often produced with an increasing rate and decreasing intensity. Palilalia has been associated with a variety of etiologies including Parkinson’s disease, stroke, and epilepsy. Because of the rare nature of this disorder, the literature involving the characteristics is limited and somewhat contradictive. Although the original definition involves increasing rate and decreasing intensity, some researchers have found different characteristics such as decreasing rate and increasing intensity when examining individual cases. This study adds to the literature regarding characteristics of palilalic speech in terms of rate and fundamental frequency changes taking place between the original utterance and the repeated trains. A single-subject design was utilized which involved a 42-year-old male who suffered an anoxic brain injury. Spontaneous speech samples were collected and analyzed. The results indicated significant differences in terms of rate but not fundamental frequency (f0) when comparing the first repeated train to the original utterance. Subsequent reiterated utterances showed no significant differences in terms of either f0 or duration.