Most parents, if not all, are used to providing their children with a teether, especially when they are on the teething stage. However, the use of teethers could impede a child's oral-motor movements and auditory speech perception, according to a new study.
First, let us explain why teethers are used. According to ShopBug, teether is an essential product for a baby to soothe their gums during the teething stage. It is designed for ease of holding and assisting the baby's development of hand-eye coordination.
Unfortunately, while the babies' hand-eye coordination improves, their speech perception is at a disadvantage because the use of teethers can restrict the tongue movements of the infants, which is necessary in their auditory speech perception.
A new study from the University of British Columbia (UBC) placed teething toys in the mouths of six-month-old English-learning babies, while they were subject to listen to speech sounds-two different Hindi "d" sounds which infants at that age can already distinguish, according to UBC News.
The researchers found out that the teethers restricted the babies' tongue movements, especially the tip of their tongue. In the process, they were not able to distinguish the two "d" sounds. However, when the babies were without teethers and when their tongues were free to move, the babies were able to make the distinctions.
According to Alison Bruderer, lead author of the study and a postdoctoral fellow in the School of Audiology and Speech Sciences at UBC the result of their study questions previous assumptions about speech and language development.
"Until now, research in speech perception development and language acquisition has primarily used the auditory experience as the driving factor," Bruderer said. "Researchers should actually be looking at babies' oral-motor movements as well."
The study is not discouraging parents to use teethers among their babies. However, it raises the question of how long infants need without teethers so they can move their tongues freely to develop speech perception normally.
This has implications for speech perception in infants with motor impairments of the mouth like cleft palate, tongue-tie or paralysis.
"This study indicates that the freedom to make small gestures with their tongue and other articulators when they listen to speech may be an important factor in babies' perception of the sounds," said senior author Janet Werker, professor in the UBC Department of Psychology.
According to ScienceDaily, this is the first study to discover direct link between an infant's oral-motor movements and auditory speech perception.
The study was published in the Proceedings of the National Academy of Sciences on Oct. 12.
