The ability of infants to recognize speech is more complicated than was previously thought, says a new study.
Researchers at the Department of Psychology, New York University (NYU), have shown that babies, even nine months old infants, are capable of distinguishing between speech and non-speech sounds in humans and animals.
AdvertisementAthena Vouloumanos, an assistant professor at NYU and the study's lead author says that their research has proved that infants' speech perception is resilient and flexible and that the recognition of speech is much more refined than what was earlier thought.
Adults' speech perception is fine-tuned to detect speech among a range of various different sounds but not much is known about babies' capabilities to assess sounds. Knowing this will help us understand how early our speech ability develops.
In order to evaluate the earliest time at which speech is perceived, the researchers studied infants' responses to recorded versions of human and parrot speech and non-speech sounds.
Human speech (an adult female voice) and parrot speech sounds included the words "truck," "treat," "dinner," and "two."The recorded parrot speech came from Alex an African Gray parrot, that had the ability to talk and reason and whose behaviors were studied by Irene Pepperberg, psychology researcher. The adult human non-speech sounds included whistles and a clearing of a throat while the parrot non-speech sounds consisted of squawks and chirps.
Infants, cannot verbally communicate, however, they tend to look longer at what they think is interesting or unusual. This was the tool to identify their speech recognition too.
Besides, the sounds were paired with a series of visuals such as a checkerboard-like image, faces of adult females and a cup.
The results of the study showed that infants listened longer to human speech in comparison to human non-speech sounds, regardless of the visuals. This clearly demonstrated the ability to recognize human speech without considering the context.
When clubbed with human-face visuals or artifacts like cups the infants listened to non-human speech, such as parrot speech, longer than they listened to non-speech. It appeared as though the infants' preferred parrot speech in the same manner they did human speech sounds. However the infants were able to distinguish animal speech from non-speech, but only in some contexts.
The study helped to confirm that infants have the ability to detect various types of speeches, even if they required visual cues to assist them in understanding the process.
The results of the study have appeared in the journal Developmental Psychology.