Auditory and visual aspects of emotion production by children and adults.

Abstract

Introduction The meaning of a communication is transmitted not only by what is said but also by how it is said and by the speaker's mood and attitude toward what is said. The speaker's tone of voice and facial expressions often provide a listener with as much information about the speaker's emotional state as does the semantic content of the utterances (Schiff & Thayer, 1974), helping listeners to better understand the speaker's intent. Thus, the ability to communicate the emotional content of spoken stimuli is an important factor for successful everyday communication. Failure to communicate these nonverbal affective aspects may create misunderstandings and poor social interactions (Rieffe & Terwogt, 2000). Although speakers may differ in their ability to express emotions, research has demonstrated that accurate judgments of emotions and feelings can be made from wordless vocal messages (Hammermeister & Timms, 1989; Siegman & Feldstein, 1987; Wallbott & Scherer, 1986). The clearest, most consistent auditory factors in signaling the speaker's emotional state were found to be the mean value of the fundamental frequency (F0), its range, and its rate of changes. Duration of production and changes in voice intensity were also described as important parameters (Scherer, 1982, 1986; Siegman & Feldstein, 1987). Neutral utterances, for example, showed changes in F0 that were relatively slow, with a smooth and continuous contour shape throughout each utterance, and length was relatively short. In contrast, the contour shapes for angry utterances showed high F0, with a considerably greater range of F0 compared to the range for neutral utterances. Also, angry utterances demonstrated a higher intensity and rate of speech (Scherer, 1986; Williams & Stevens, 1972). Visual transmission of emotions is considered to be even more efficient. Visual cues regarding emotions are clear, and observers can reliably identify different emotions based on them (Fridlund, Ekman, & Oster, 1987; Hess, Kappas, & Scherer, 1988; Most, Weisel, & Zaychik, 1993; Wallbott & Scherer, 1986). Researchers have suggested that anger, disgust, happiness, fear, sadness, and surprise are each expressed visually in a universal way (Ekman, 1982). Previous Research on Children's Production of Emotions Young children's ability to produce emotions has been a focus of previous research, but mostly emphasizing the development of facial expressions rather than vocal output (Plutchik, 1994). Ekman and Friesen (1976) as well as Ekman and Oster (1979) claimed that even young infants (a few months old) exhibit 24 different recognizable facial expressions in response to various stimuli. Among 8-12 month olds, Young and Decarie (1977) identified 42 different facial expressions and 10 different vocal outcomes. Ekman and Oster (1979) summarized some of their conclusions in reference to infants' facial expressions as follows: 1. Facial musculature is fully formed and functional at birth. 2. Expressions similar to those of adults already appear in early infancy. 3. Infants aged 3-4 months show different facial expressions in response to exaggerated expressions of their caretakers. 4. Imitation of some facial expressions of the caretaker was seen among infants at age 2-3 weeks. 5. Preschool children know how most common facial expressions look, what they mean, and what kinds of situations typically elicit them. 6. Facial expressions play a role in social communication. As reported above, emotion, like other communicative intentions, is sometimes expressed through prosody alone, with no other cues (Gerard & Clement, 1998). Research has shown that young children already produce correct intonation, which means that they have acquired some prosodic elements. Nevertheless, the various typical prosodic patterns that are expressed during the production of specific emotions appear only later in life (Gerard & Clement, 1998). …