You may find baby talk to be nonsensical, but according to a new Canadian study, to other infants this babble is not just enthralling but integral to their language acquisition. Researchers found that 6-month-old infants prefer listening to other babies talk than they do adults, a finding which may lead to new avenues of treatment for infants whose hearing impairment may have hindered their language skills.

In a study carried out by researchers at McGill University in Canada, researchers ran a series of experiments where they exposed 6-month-old infants to a series of recordings. While seated on a woman’s lap, the infants listened to a repeating vowel sound made by a synthesizer mimicking either the voice of an adult woman or a baby. The researchers measured how long the sounds held the babies' attention; they ultimately observed a clear preference for the infant voices.

According to the press release, the babies paid attention to the infant voice 40 percent longer than they did the adult one. The facial expression of the infants also changed depending on what track they were being played. In the video recording of the experiment, you can see that when some babies heard the adult voice, they maintained a fairly neutral expression, but when they heard the infant voices, many babies began to smile or move their mouths as they listened.

The reason babies prefer the sound of other infants cannot be confirmed, but the researchers involved in the study theorize it may be because they recognize the infant speech as a sound they are capable of recreating. If so, it may be that communicating with other infants or with adults who mimic infants' high-pitched single vowel noises may be integral in humans learning to speak.

"Perhaps, when we use a high, infant-like voice pitch to speak to our babies, we are actually preparing them to perceive their own voice," said Professor Linda Polka, senior author on the study, in the press release.

According to Polka, the speech process begins with first understanding how the mouth works and involves moving the mouth and vocal cords. Hearing sounds that sound similar to their own may help with this.

The study highlights the complex and minimally understood link between speech perception and speech production in infants. This finding is important because understanding the process in which we first begin to learn how to speak can help speech pathologists become better equipped at teaching the skill in the most natural way possible.

Source: Masapollo M, Polka L, Merard L. When infants talk, infants listen: pre-babbling infants prefer listening to speech with infant vocal properties. Developmental Science. 2015.