Importance of Instructional Set to Psychoacoustical Scaling

Carefully presented instructions are a basic requirement of successful psychoacoustical scaling studies. The term in the instructions which refers to a subjective experience uniquely defines the type of scale constructed. This paper describes the degree to which a psychoacoustical scale would be modified by changes in instructions. The results of 2 studies are reported. The first discusses the differences in subjects' responses to instructions based on 3 different key words—loudness, noisiness, and annoyance. The second is concerned with the effect on subjects' responses of mixed instructions (i.e., where more than one key word appears in a single set of instructions). The results indicate that different instructions “set” subjects to give different emphasis to various physical aspects of sound, and that instructions based on a combination of 2 key words yield ratings significantly different from ratings given to the same sounds when the key words are used individually. A recommendation is made that instructions be selected which set subjects to emphasize sound dimensions relevant to particular noise problems.