AN EXAMINATION OF THE ACOUSTICAL DETERMINANTS OF ADULT RATINGS OF INFANT CRIES (PRETERM, AVERSIVENESS)

KATHLEEN ANN JACOBSON, Purdue University

Abstract

Recent research on infant crying has suggested that especially aversive sounding cries may have an adverse effect on the caregiving behavior of adults. This study was an attempt to identify acoustic differences between more or less aversively rated cries, to examine differences in the ratings and acoustic parameters of high risk and normal infant cries and to test the reliability of aversiveness ratings of cries by adults. Pain cries were recorded from 20 normal infants and from 20 high risk, primarily preterm, infants just prior to hospital discharge. Subjects rated these cries on an aversiveness scale. Another set of subjects rated cries a second time, in a different order of presentation, providing test-retest reliability data, and also, on a third presentation, rated the cries on a set of additional subjective dimensions. All cries were submitted to spectrographic analysis, yielding a set of twenty-three acoustic measures on each cry. Data analyses revealed acceptable test-retest reliability of cry aversiveness ratings. There were no differences in aversiveness or other ratings assigned to high risk and normal cries, in contrast to many recent studies. This finding is discussed in relation to the observed acoustical differences found between high risk and normal cries as well as in relationship to the methodological differences between this and earlier studies. It is concluded that artificial variations in playback of cries in other studies and extremely small sample sizes may have produced the rating differences that have been previously reported. Cries were then separated into two groups based on mean aversiveness ratings assigned to the cries and a discriminant analysis was conducted. Nine of the 23 acoustic measures were capable of discriminating between the two sets of cries. More aversive cries contained higher peak sound levels, a higher percentage of mid- to high-frequency cry sounds, more variability on several dimensions and more consistent and longer duration inspiratory sounds. Suggestions are offered for future research in this area.

Degree

Ph.D.

Subject Area

Psychotherapy

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