Message delivered: Assistive tech bridges spoken language gap in kids with impaired hearing

Speech and language therapy, as supplemented with augmentative and alternative communication (AAC) technology, allows children who are deaf or hard of hearing (DHH) to process and comprehend spoken language more fully, as shown in a study.

“Even with appropriate access to sound, DHH children do not have the same quality of auditory experience and do not perceive speech and acquire language in the same way as individuals with hearing,” according to researchers from the University of Cincinnati and Cincinnati Children’s Hospital Medical Center in Ohio, US. [J Speech Lang Hear Res 2013;56:1701-1714] 

“To learn and produce spoken language, children require adequate access to spoken language models, traditionally relying on auditory input and vocal output channels, both of which are temporally based (ie, sequences in time) and dynamic (ie, a rapidly fading nature),” they added.

AAC technology employs visual learning and places more weight on the role of graphic symbols in language development, the researchers pointed out. It works by providing stationary and spatially based visual supports, or picture boards, and repeated listening opportunities for key aspects of verbal language that are often difficult for DHH children (ie, low-emphasis language constructs, word endings, verb tense, plurality, and possessives). [Am Ann Deaf 2014;159:346-358] 

In a trial, 41 children (mean age, 6.3 years) with mild to profound bilateral hearing loss were randomized to undergo the technology-assisted language intervention (TALI; n=21) or treatment as usual (TAU; n=20) for 24 weeks. The TALI cycle consisted of 6 weeks of therapy with a speech-language pathologist (hour-long, weekly sessions) and 6 weeks of self-guided training at home using an AAC software on a tablet device, then another round of both.

Over time, children who underwent TALI made better progress in terms of the phrases they used to express themselves (p<0.0001). Mean length of utterance (MLU) in morphemes, which indicated syntax and morphology complexity, increased by 43 percent versus only 6 percent among those in the TAU group. [Pediatrics 2021;doi:10.1542/peds.2020-025734]

Similar results were seen for other endpoints. Compared with TAU, TALI resulted in a significantly greater increase in the mean length of conversational turn in words (48 percent vs 11 percent) and in the number of different words spoken (from 82 to 104 words vs from 82 to 87 words).

World of sound unlocked

The study delivers a clear message: that spoken language is a possibility for DHH children.

“With appropriate visual supports and language-teaching tools, as used in TALI, DHH children are capable of developing language skills more commensurate with their cognitive abilities and flourishing in previously challenging communicative situations,” according to the researchers.

They pointed out that the children included in the study were aged 6 years on average, yet they their MLU aligned with that of a 4-year-old child without hearing loss. “This discrepancy indicates a significant gap in spoken language skills that could impact longer-term outcomes. By 24 weeks, MLU increased … for the TALI participants, on par with children aged 6 years.” [J Speech Hear Res 1981;24:154-161]

Language deficits in DHH children go hand in hand with social and academic difficulties that often persist into adulthood, the researchers noted. “The significant boost in both spoken and receptive language our DHH children experienced as a result of the TALI could potentially help mitigate [these] struggles.”

Then again, it is too early to say whether the TALI could prevent a language gap. The researchers acknowledged that they could not determine whether children younger than age 3 years could meaningfully engage in AAC-supplemented therapy because it required the cognitive skill of tying linguistic meaning to graphic symbols.

“Although our study findings require further exploration, they bring excitement to the potential for improved outcomes for DHH children,” they said, adding that there may also be other high-risk populations for whom this approach could effectively promote improved language development.

“Future work includes expansion to include more diverse populations of children across different settings (multiple study sites) with a larger sample size,” according to the researchers.