Perceptual dimensions of infant cry signals: a semantic differential analysis

Alteration of Adults' Subjective Feeling of Familiarity toward Infants' Sounds

Many adults may have lower subjective feelings of familiarity toward infants' vocalizations since infants' sounds are different from those of adults. However, mothers frequently exposed to infants' vocalizations may be more familiar and less averse. To test this hypothesis, 21 mothers ( M age = 31.1 yr., SD = 4.3) of infants ( M age = 8.2 mo., SD = 3.5), 18 mothers ( M age = 34.4 yr., SD = 4.8) of children between two and five years of age ( M age = 2.8 yr., SD = 1.0), and 17 women ( M age = 29.2 yr., SD = 11.1) with no children were exposed to 20 types of sounds. Of these sounds, 14 were produced by infants. Although the mothers of infants did not recognize sounds as those of an infant's vocalization, they showed higher subjective feelings of familiarity toward the timbres of the vowel-like stimuli than did the other groups. By contrast, the subjective feelings of familiarity for nonspeech sounds did not differ among groups. Maternal experiences may change women's recognition of perceived sounds.

Developmental changes in pain expression in premature, full-term, two- and four-month-old infants

The purpose of this study was to examine the behavioural responses of infants to pain stimuli across different developmental ages. Eighty infants were included in this cross-sectional design. Four subsamples of 20 infants each included: (1) premature infants between 32 and 34 weeks gestational age undergoing heel-stick procedure; (2) full-term infants receiving intramuscular vitamin K injection; (3) 2-month-old infants receiving subcutaneous injection for immunisation against DPT; and (4) 4-month-old infants receiving subcutaneous injection for immunisation against DPT. Audio and video recordings were made for 15 sec from stimulus. Cry analysis was conducted on the first full expiratory cry by FFT with time and frequency measures. Facial action was coded using the Neonatal Facial Action Coding System (NFCS). Results from multivariate analysis showed that premature infants were different from older infants, that full-term newborns were different from others, but that 2- and 4-month-olds were similar. The specific variables contributing to the significance were higher pitched cries and more horizontal mouth stretch in the premature group and more taut tongue in the full-term newborns. The results imply that the premature infant has the basis for communicating pain via facial actions but that these are not well developed. The full-term newborn is better equipped to interact with his caretakers and express his distress through specific facial actions. The cries of the premature infant, however, have more of the characteristics that are arousing to the listener which serve to alert the caregiver of the state of distress from pain.

Comparison of Semantic Differential Scale Sets for Describing Infants' Cries

The present study examined the relationships between the scale sets reported by Brennan and Kirkland in 1983, Mehrabian and Russell in 1974, and Zeskind and Lester in 1978. A combined factor analysis of listeners' ratings on 10 short cry sounds confirmed the factor structures reported earlier. The eight Zeskind and Lester scale items as well as the Mehrabian and Russell pleasure/displeasure factor-scale items loaded on a single factor, named Affect, which is a subset of the Brennan and Kirkland scale set. The results suggest listeners' feelings of arousal cannot be accounted for solely in terms of the unpleasant/arousing qualities of cry sounds or attributed to either the potency or the perceived importance of the cries.