Visual Fixation and the Effect of Voice Quality and Content Differences in 2-Month-Old Infants

Abstract

The purpose of the two studies to be reported here was to extend the findings reported by Boyd in Chapter VI to other characteristics of natural language stimuli using the same technique. It has been shown that young infants can make very fine distinctions in isolated language-related stimuli such as consonants (Eimas, Siqueland, Jusczyk, & Vigorito 1971; Moffitt 1971; Trehub & Rabinovitch 1972). While it is possible that early languagelistening experience for the infant is characterized by some sort of systematic attention to single language elements, the environment, in fact, presents the infant with very complex and extended, though probably repetitious, language samples. There have been several reports that have given evidence concerning the role of complex language stimuli in infant behavior (Tulkin 1971; Tulkin & Kagan 1972; Turnure 1971). The most consistent findings seem to relate to social class variables. And, the subjects of these studies were all over 3 months of age and most of them older. The Boyd demonstration with 7and 8-week-old infants is probably the clearest evidence at the youngest age that infants can discriminate between two different voices with all the complexity and grossness involved in such stimuli. However, Lewis (1951) reported that infants respond to an adult voice by