Mechanisms of auditory perception and vocal production in humans are derived traits from our ancestor primates. In contrast to non-human primates, human infants develop spoken language quickly and almost mindlessly (Mampe et al. 2009). There are many genetic studies that explain the difference of language acquisition and discussions on cross-cultural variation. Perhaps we can also explain both issues through the middle-ground of behavioural and physiological development.
“Prosodic features such as melody, intensity, and rhythm are essential for an infant acquiring language.” – Mampe et al. 2009
Perception of the Voice
Exposure to auditory stimuli during pregnancy influences newborns’ perception of sounds. Human fetuses start to react to sounds from about 30 weeks of gestational age (Kisilevsky et al. 2016). They can memorize prosodic features (accent and tone of syllables) from the outside world by the last few months of pregnancy, developing sensitivity to melodic contours (rises and falls of pitch) in both music and language (Mampe et al. 2009). This maturing ability to process pitch intervals enables them to proficiently appreciate musical melodies and emotional and linguistic prosodies once they are born.
As foreigners residing in Korea, Dave (American) and his international friends (French, German and Spanish) compare each other’s native languages for certain words. They demonstrate the obvious differences in linguistic pronunciation. Although it is not as apparent in this video, languages in general can be differentiated through trends in melodic contours. As mentioned previously, perception of prosodies are learnt as early as the prenatal period. This contributes to sound production of the infant’s native language when they start to learn and speak their mother tongue.
Production of the Voice
Newborns may have learned prosodic traits of their native language by listening to them inside their mother’s womb. A study analyzed crying patterns of French and German newborn babies in terms of their melody and intensity contours (Mampe et al. 2009). The French group had a tendency to produce cries with a rising contour, but the German group produced falling contours (Figure 1). These patterns are consistent with the intonation trends heard in both languages – French intonations typically have a pitch rise towards the end of sentences, whereas German intonations usually display a falling pitch. Not only have they acquired the main intonation patterns of their surrounding language, but they also have the ability to reproduce these patterns in their own vocalizations.
Learning language is usually discussed through cultural or genetic aspects of sociality, cognition and vocal articulation. Evidence of how a newborn’s cry is shaped by hearing their native language from established speakers in the external environment reveals the direct interaction between culture and biology. Since the established speakers also went through the same prenatal conditioning, we can say that it is an open and cyclical system of nature nurturing nature.
Kisilevsky, B. S., Hains, S. M. J., Lee, K., Xie, X., Huang, H., Ye, H. H., Zhang, K., Wang, Z. (2016) Effects of Experience on Fetal Voice Recognition. Psychological Science 14(3): 220-224.
Mampe, B., Friederici, A. D., Christophe, A., Wermke, K. (2009) Newborns’ Cry Melody Is Shaped by Their Native Language. Current Biology 19: 1994-1997.