Language exposure for children is the act of making language readily available and accessible during the critical period for language acquisition. Early exposure to language enables the brain to develop cognitive function more fully and facilitates the development of language skills that support language fluency and comprehension later in life. Children who are d/Deaf and hard of hearing, compared to their hearing peers, tend to face barriers in developing language. Consequently, deaf and hard of hearing children are more likely to experience language deprivation, which may lead to cognitive delays and additional negative impacts on their health. However, research has guided the development of strategies to enhance language development and reduce deprivation. Examining language acquisition in deaf and hard of hearing children has resulted in more substantial evidence regarding the risks and benefits of early language exposure. Much of this research focuses on children in the United States, which limits its generalizability.
Critical period The critical period for first language acquisition is a linguistic theory that suggests there is a specific window of time when a language can be acquired. After this period, it becomes significantly more challenging to develop a first or second language. Many theories exist regarding the exact timing of the critical period for language acquisition; however, research indicates that when a child does not receive language exposure during their first few years of life, they may experience long-term language development deficits.
Much of the research on language exposure, the critical period, and language acquisition is based on spoken languages and hearing children. In reality, these same ideas also apply to deaf and hard of hearing children. For hearing children, first language exposure often begins with their parents' native language. The same is true for deaf and hard of hearing children with Deaf parents; they are exposed to sign language at birth.
However, language exposure for deaf and hard of hearing children born to hearing parents is often delayed. Early in life, deaf and hard of hearing children are typically primarily exposed to spoken language, as their parents may not have learned sign language. Consequently, deaf individuals often do not encounter sign language until later in childhood or even adulthood, regardless of their success in spoken languages. Research concludes that it is not hearing loss itself that affects language impairment, but rather a lack of sufficient language input during the first year of life. Children who are exposed to language during their first year of life typically exhibit normal language development, even if they later develop hearing loss.
Early hearing detection and intervention (EHDI) Currently, within the United States, newborn hearing screening practices are in place that inform parents of their newborn's hearing status within the first few weeks of the child's life. The HRSA-funded Early Hearing Detection and Intervention (EHDI) protocol adheres to a 1-3-6 rule: an infant should have their hearing screened by one month of age, diagnosed by three months, and enrolled in early intervention services by six months. Programs in the United States are divided into states and territories, and aim to screen, provide diagnoses, develop family support systems, and coordinate services for deaf and hard of hearing children to achieve language milestones. Data is collected from these programs to assess the success of screening and intervention programs in the hopes of optimizing care for deaf and hard of hearing children.
Diagnosis Approximately 90–95% of deaf and hard of hearing children are born to hearing parents, while 5–10% are born to Deaf parents. After an infant is born, they undergo a hearing screening using an auditory brainstem response (ABR). This test involves placing electrodes on the infant’s head to present pure tones and observe the resulting electrical activity in the brain. In the event that the infant fails the newborn hearing screening, a follow-up screening appointment will be scheduled. Should the infant also fail the second screening, it is essential to schedule a consultation with an audiologist to determine the next steps. If the audiologist diagnoses the infant with hearing loss, they will typically refer the child to an Ear, Nose, and Throat (ENT) specialist, specifically a pediatric otologist. This specialist focuses on ear conditions to help ensure that the baby develops language skills effectively. However, some physicians report that they are not confident in informing parents of deaf and hard of hearing children about additional steps to take beyond visiting an audiologist.
Later language ability There has been additional research on fluent sign language users and their ability to acquire spoken language later in life. Both signed and spoken language establish a strong foundation in the general language abilities, needed for reading, learning and basic expressive and receptive language skills. If language is acquired after the critical period for language acquisition, this foundation is not established.
Additionally, research indicates that children who learn sign and spoken language during the critical period of language acquisition develop comparably to bilingual children.
Benefits of language exposure Sign languages such as American Sign Language have been recognized as official languages following research that began in the 1960s. Research has established that signed languages encompass the same linguistic complexity as spoken languages, with intricate structures, syntax, and grammar that are comparable to those found in spoken languages. Furthermore, they both utilize the same regions in the left hemisphere of the brain for planning and processing language.
Both deaf children and hearing children with proper language exposure and education have normal cognitive development. In fact, deaf children and hearing children have similar language milestones and timelines. According to language development and milestone sources, babies who can hear and are exposed to language typically start to babble (e.g., ma-ma, da-da) between the ages of six and twelve months. Similarly, deaf babies that are exposed to a signed language will start to "babble" with their hands by using organized and repetitive elements of their signed language.
In keeping with this, deaf, hard of hearing, and hearing children have equal potential to develop typical cognitive abilities; deafness does not directly cause any cognitive impairments or language delays. However, deaf and hard of hearing children are at much higher risk for having inadequate exposure to language during their critical periods which can in turn cause cognitive and language delays.
Language development For children who can hear and speak, first language exposure usually starts with their parents' native language. There are two primary approaches proposed for exposing deaf and hard of hearing children to language. The first is through sign language, and the second is through spoken language. However, it is not necessary to choose one or the other. Research indicates that learning two languages, regardless of the specific languages themselves, can offer unique cognitive benefits. For deaf and hard of hearing children in particular, learning both a signed language from birth and spoken/written language can protect the child from the harms that come from language deprivation, which occurs when a child is delayed in accessing language in any modality. This suggests that learning two languages, irrespective of the languages themselves, can provide distinct cognitive advantages to bilingual individuals. Furthermore, bilingualism opens up more opportunities for the individual by enabling them to interact with users of multiple languages.
Sign language When deaf children are born to Deaf parents who use sign language, their language exposure is constant and fully accessible from birth. This is equivalent to the quality of language exposure received by hearing children. These children thus demonstrate typical language acquisition. However, most deaf and hard of hearing children have hearing parents with little to no experience in sign language. There are many options available to these parents to help them provide their child with as much fully accessible language as possible from birth onward.
Sign languages may differ by country, and even by region. Support from academic institutions such as Gallaudet University has led to global efforts to establish an international signing community through student exchanges. Many of these programs offer volunteer opportunities to improve language exposure for children in countries where sign language is not formally integrated into their primary school curriculum.
Cochlear implants and exposure
Many doctors recommend that families with babies diagnosed with hearing loss see an audiologist. To some, an audiologist referral is an attempt to solve a problem of hearing loss. To others, it is seen as an act of denying the baby a chance to explore and become a part of the Deaf community. Since their introduction, there has been a heated debate over research on cochlear implants. This surgery is a common recommendation for children born deaf, in an attempt to help the child hear, understand, and use spoken language, alongside or in addition to sign language.
The debate primarily centers on the view that deafness is a problem that needs to be addressed, a phenomenon referred to as deficit framing, which may include terminology such as "hearing-impaired." Many proud members of the Deaf community view the implantation as trying to fix someone who is already whole, and may find this insulting and even unethical. Others view it as a very real possibility to open doors and give children the opportunity to function with more accessibility in a hearing society.
In 2018, a systematic review of all the literature on cochlear implants and language acquisition outcomes was published, which concluded that it is unlikely for most deaf children to catch up to their hearing peers in spoken language acquisition through the use of cochlear implants. However, language outcomes were better when the child received access to language (in this case, spoken language through implants) at an earlier age. One solution that has been proposed to address this issue is to provide exposure to sign language for all deaf children as early as possible, regardless of plans for pursuing cochlear implants or hearing aids later on. This strategy ensures the maximum possible language exposure for children. It mitigates the risk of language deprivation often associated with waiting to see if cochlear implants will be successful for any given child.
Parent Resources Most deaf and hard of hearing children have hearing parents with little to no experience in sign language. There are many options available to these parents to help them provide their child with as much fully accessible language as possible from birth onward.
First, many schools for the deaf offer sign language classes to parents who want to learn to sign with their child. Some schools even offer parent–infant programs, which allow parents to bring their infants to the class. These programs offer both language instruction to parents and sign language exposure to infants, as well as structured playtime that allows parents and infants to interact in sign language with signing instructors present to facilitate and answer questions.