An infant’s first three years of life are their most intensive period for acquiring language. At this stage, parents often speak to their children to stimulate language development and avoid communication challenges later on for their infant. However, this period can be difficult to navigate for speaking parents of deaf infants, as the children cannot absorb the parents’ spoken language.
Expert opinions on how to navigate early childhood education for deaf infants have changed over the years. In the nineteenth and early twentieth centuries, teachers often discouraged sign language for deaf children, instead focusing on lip reading and producing speech sounds. In addition to the ethical concerns around preventing children from accessing communication methods that are most natural to them, current research shows that this approach may impair children’s language development. Audrey Delcenserie, a McGill graduate pursuing a PhD at the Université de Montréal, has published a paper regarding language deprivation and its adverse impacts on deaf children’s linguistic development.
“If you don’t expose [deaf children] to sign language, they actually go through linguistic deprivation, as they are not exposed to auditory inputs and they are not exposed to visual inputs,” Delcenserie said in an interview with The Tribune. “This means that [deaf children] start [language learning] after what we call the ‘critical’ or ‘sensitive’ period for phonological development.”
If deaf children only begin learning language after this critical period, they may struggle with learning any language, whether it be visual or auditory. As such, Delcenserie emphasized that parents should use any available resources to teach their children sign language.
The Visual Takeover Hypothesis (VTH) is often cited by those concerned with sign language being taught to deaf children, as the hypothesis asserts that learning a visual language may impair auditory language development. This hypothesis argues that deaf children who receive a cochlear implant—a device that makes sound waves perceptible to deaf individuals by synthesizing the waves—later struggle with auditory language, as their brain has been primed for visual learning.
However, Delcenserie argued that the concerns regarding the VTH are overstated. She asserted that exposure to any language, even in suboptimal conditions, is better than having no exposure at all.
“An increasing number of studies show that [the VTH] is not the case,” Delcenserie said. “The changes that happen in the brain are actually more of a consequence of deafness itself than exposure to signs.”
In Delcenserie’s research, she observed positive outcomes in cognitive growth for children who were exposed to sign language. Delcenserie calls these children ‘multimodal bilinguals,’ as they show proficiency in both auditory and visual languages and have the potential to further develop these skills.
“As the results point out, [multimodal bilingual] kids actually do quite well in terms of auditory perception when we tested these kids in French,” Delcenserie explained. “So this means their exposure to sign language may not be detrimental for their acquisition of French.”
Delcenserie also stated that even if VTH was a valid model, the speech pathology community would need to decide whether auditory difficulties are preferable to language deprivation.
“It’s possible that my results may not be replicated, and that people will come up with different results—it’s science, it’s perfectly fine,” Delcenserie said. “Even if [VTH] is true, I think parents should ask themselves what’s the best for their child: These perceptual difficulties, or language and cognition?”
Delcenserie is hopeful that her paper will positively contribute to the discourse on sign language exposure and its benefits for deaf children.
“It’s quite clear that an increasing number of studies actually suggest that not exposing kids to any language input, whatever the modality is, is detrimental for language acquisition and cognitive development,” Delcenserie explained. “I don’t really know why [some speech pathologists] persist in thinking that linguistic deprivation might be a good idea, but I hope the article will help.”
