Investigation of the Assessment of Infant Vocalizations by Laypersons

TL;DR

This study investigates how laypersons assess infant vocalizations, identifying key labels and their relation to affective ratings, and proposes classification schemes based on these insights.

Contribution

It is the first to analyze layperson assessment behavior of infant vocalizations and to propose classification schemes based on salient acoustic labels and affective ratings.

Findings

Identified 9 salient vocalization labels

Valence has the strongest association with label ratings

Stimuli are best grouped into 3-5 classes for separability

Abstract

The goal of this investigation was the assessment of acoustic infant vocalizations by laypersons. More specifically, the goal was to identify (1) the set of most salient classes for infant vocalizations, (2) their relationship to each other and to affective ratings, and (3) proposals for classification schemes based on these labels and relationships. The assessment behavior of laypersons has not yet been investigated, as current infant vocalization classification schemes have been aimed at professional and scientific applications. The study methodology was based on the Nijmegen protocol, in which participants rated vocalization recordings regarding acoustic class labels, and continuous affective scales valence, tense arousal and energetic arousal. We determined consensus stimuli ratings as well as stimuli similarities based on participant ratings. Our main findings are: (1) we identified 9 salient labels, (2) valence has the overall greatest association to label ratings, (3) there is a strong association between label and valence ratings in the negative valence space, but low association for neutral labels, and (4) stimuli separability is highest when grouping labels into 3 - 5 classes. We finally propose two classification schemes based on these findings.