Humans instinctively adapt their speech dynamics based on their communication partner. Despite the significant developmental differences between infants and older adults, research on vocal communication directed toward older adults has primarily documented broad adjustments that enhance comprehension, often interpreted as mirroring baby talk. This study examined spoken, sung, and whispered vocalizations produced by young native English-speaking female adults directed at infants, older adults, and young adults. Three separate groups of speakers produced either spoken (19 speakers), sung (21 speakers), or whispered (19 speakers) vocalizations. Results showed distinct acoustic patterns in vocalizations directed toward older adults across all three vocal modes. Then, three separate groups of young native English-speaking listeners evaluated either the spoken (185 listeners), sung (194 listeners), or whispered (171 listeners) vocalizations and accurately identified the intended audience. These findings challenged the assumption of uniform communication strategies for infants and older adults. Furthermore, older adult-directed vocalizations were associated more with infants than with young adults. We propose that an assessment of the cognitive, hearing, emotional, and attentional needs and abilities of the audience is crucial in shaping communication dynamics, leading to distinct vocal dynamics for infants and older adults. (PsycInfo Database Record (c) 2025 APA, all rights reserved).
Ma et al. (Thu,) studied this question.