A Study of Intonation Patterns in Echolalic Responses of Autistic Children

Abstract

Intonationrefers to distinctive patterns of vocal melody. Supra-segmental aspect of speech is multifaceted and has many features like pitch, loudness, duration and pauses and components like intonation, tempo, stress and rhythm. The melodies of speech are related to virtually all levels of verbal communication, including emotional expression, pragmatics, and syntactic structure. On the acoustic level, melody patterns result from linguistically significant changes in the fundamental frequency (f0 ) of the voice. Intonation providesinformation regarding discourse; attitudes, intentions and speech register. These can be distinguished based on some typical pitchcharacteristics such as rise or fall of FO, terminal FO counter and overall contour. It is well evidenced that many individuals with communicationimpartment due to hearing and neurological disorders and autism have difficulty inproducing the intonation pattern. Intonation patterns have been considered as an important area of research in children with autism. The present study was attempted to compare the imitated utterance in response to clinician and caretaker. A total of 30 children with Autism (verbal type), aged 4-9 years, served as participants. Children with any identified genetic disorder, sensory deficit, severe motor deficit, associated mental retardation (IQ<70), were excluded. A list of five spontaneous daily utterances (Good morning, Good afternoon, Thank You, Bye bye, Goodnight) was presented to elicit responseafter the clinician as well as caretaker utterances. All the utterances were recorded with PRAAT (version 5.3.30) software through a computer. The utterance samples were grouped as after clinician, after caretaker, and then analyzed acoustically using PRAAT. The factors analyzed were Mean pitch, Median, Minimum pitch, Maximum Pitch. Further, the intonation pattern for each utterance was also noted for rising, falling, fall rising and rise falling pattern.In these autistic children undergoing speech language therapy and home training, the generalacoustical parameters of the echolalic of the everyday utterance did not differ significantlybetween the clinician and parental presentation. However the pitch range exceeded mean 100Hzfor all utterances, similar is the study in agreement with some of the recent studies studying theimitation of prosodic patterns. The intonation contours were predominately rising pattern and to alesser extent rise falling. The present study indicates that the intonation contours mentionedabove are significantly different for clinician and caretaker presentation. It is possible that the autistic children may experience poor sensoryexpressive particularly auditory and this may affect the development of intonation.