Does change in timbre alter stereotypy movements exhibited by three persons with diagnoses of mental retardation and autism spectrum disorder: Three case studies
The purpose of this study was to observe and collect data while monitoring the responses of three individuals to recorded presentations of four folk songs. The individuals, or participants, were all residents of a state-run facility in the southern region of the United States. The participants were females diagnosed with mental retardation and autism spectrum disorder, and they all exhibited one or more stereotypy behaviors in some form or another. The primary purpose of the study was to see if change in timbre of the songs would alter the stereotypy movements exhibited by these participants as the songs were presented to them. The four songs chosen were Danny Boy, All Through the Night, To the Sky, and Amazing Grace. In an effort to control as many variables as possible within reason, the pieces were chosen for their similarity of style and melodic contour and were all presented in keys of either F major or C major. The timbre presentations of each piece were (1) mezzo-soprano, melody only, a cappella; (2) bass-baritone, melody only, a cappella; (3) piano, melody only; (4) acoustic guitar, melody only; (5) tone chime, melody only. Assisting the researcher in collecting the data for the study was the participants' psychologist. Assessment instruments for data collection were a journal completed by the researcher during the study and a behavior data sheet made for each participant with a separate sheet for the timbral presentation of each song. Also, there was a questionnaire for the psychologist to answer concerning each participant that covered the overall impression of the study for that participant. Once the study was completed, the researcher and the psychologist met and discussed the assessment instruments and found that overall, change in timbre did alter the stereotypy movements of the participants in differing ways. It was agreed that of all the timbres presented, the two timbres which had the most positive effect, that of slowing or stopping the engagement of stereotypy, were the mezzo-soprano and the piano. The timbre that had the least positive effect, that of accelerating or causing the exhibition of stereotypy, was the bass-baritone. Possible reasons for these effects were discussed and reported along with implications of the research to the field of music education.