Learning to differentiate individuals by their voices: Infants' individuation of native‐ and foreign‐species voices

Abstract

The ability to discriminate and identify people by their voice is important for social interaction in humans. In early development, learning to discriminate important differences in a number of socially relevant stimuli, such as phonemes and faces, has been shown to follow a common pattern of experience-driven perceptual narrowing, where the discrimination of native stimuli improves, while the discrimination of foreign stimuli worsens. The aim of the present study was to investigate whether similar perceptual narrowing occurs for discriminating individuals by voice. We tested the ability of English-speaking adults and English-learning 6- and 12-month-olds to discriminate either native-species (human) or foreign-species (rhesus monkey [Macaca mulatta]) individuals by their vocalizations. Between 6 and 12 months of age, the ability to discriminate monkey voices decreased significantly and there was a non-significant trend for improved ability to discriminate human voices. The results support the hypothesis of experience-driven perceptual narrowing for voice individuation during the first year after birth.

Plasticity after perceptual narrowing for voice perception: reinstating the ability to discriminate monkeys by their voices at 12 months of age

“…In a previous study, we demonstrated that the ability to discriminate individuals by voice follows a pattern of perceptual narrowing (Friendly et al, 2013). Specifically, we found that the ability to discriminate between two foreign-species (rhesus monkey) voices decreased significantly between 6 and 12 months of age.…”

Speech-Evoked Brainstem Response

“…However, additional studies have been initiated in numerous languages such as Arabic, Brazilian Portuguese, French, Greek, Hebrew, Indian, Japanese, and Persian [1,11,13,[22][23][24][25][26][27][28][29][30][31][32].…”

“…Regarding the stimulated ear, the great majority of studies performed the assessment of ABR with speech stimuli elicited only on the right ear, which can be explained by the advantage of right ear in encoding speech by contralateral projection to the left hemisphere [24,26,29,31,32,[36][37][38][39][40][41][42][43][44].…”

“…The syllable / da/ is most well known and applied more often in studies [11,13,15,22,25,28,29,32,36,39,45,47]. However, there are researchers who used disyllables as /baba/ [27] or even other syllables composed by consonant-vowel as /ba/ [23,30,31].…”

The Effect of Prenatal Auditory Enrichment on Perceptual Narrowing in Bobwhite Quail Neonates

“…Friendly, Rendall, and Trainor (2013A) found that between 6 and 12 months, human infants lose the ability to distinguish between two voices of a non-human primate species (rhesus monkeys). That is, withholding the rhythmic properties of the primate calls, the 12-month old infants could not use the auditory-only properties such as pitch or timbre to effectively discriminate between two individual rhesus monkeys; something they were able to do 6 months prior.…”