Infants can distinguish between animal, human sounds

Infants as young as nine months old can recognise speech, and distinguish between human and animal sounds, according to a new study.

“Our results show that infant speech perception is resilient and flexible,” Athena Vouloumanos, an assistant professor at New York University, Department of Psychology and the study’s lead author said.

“This means that our recognition of speech is more refined at an earlier age than we’d thought,” she added. The study appeared in the journal Developmental Psychology.
It is well-known that adults’ speech perception is fine-tuned—they can detect speech among a range of ambiguous sounds. But much less is known about the capability of infants to make similar assessments.

In order to measure the aptitude to perceive speech at an early age, the researchers examined the responses of infants, approximately nine months in age, to recorded human and parrot speech and non-speech sounds.

Since infants cannot verbally communicate their recognition of speech, the researchers paired sounds with a series of visuals. Under this method, looking longer at a visual paired with a sound was interpreted as a reflection of recognition.

The results showed that infants listened longer to human speech compared to human non-speech sounds regardless of the visual stimulus, revealing their ability to recognise human speech independent of the context.

“Parrot speech is unlike human speech, so the results show infants have the ability to detect different types of speech, even if they need visual cues to assist in this process,” Vouloumanos said.