Have you ever been around a child who’s learning how to talk? They'll start with nonsensical sounds — hours and hours of “muh-muh-muh” — and graduate to words. Usually, they’re simple words like “mama,” which charts near the top of the first-words hit parade.

During that process, bilingual children need to know how to properly form the sounds of two languages. For example, the “th” sound in English words like “bath” has no Spanish equivalent. And then there’s the rolled “r” sound in Spanish, which doesn’t occur in English and often proves difficult for native English speakers. They also need to understand which sound belongs to which language and be able to pronounce them well enough for others to understand.

Latino children make up 25 percent of elementary school students in the U.S., a figure that is expected to rise to 30 percent by 2030, according to the National Center for Education Statistics. Yet when it comes to diagnosing speech sound disorders in bilingual children, 40 percent of speech-language pathologists say they are more likely to avoid diagnosing a communication disorder due to their own lack of knowledge.

It's a problem Leah Fabiano-Smith, an associate professor in the UA Department of Speech, Language and Hearing Sciences, hopes to solve with a five-year, $2.5 million National Institutes of Health Research Project Grant through the National Institute on Deafness and other Communication Disorders. Her research involves an issue that is critical in Arizona and other states with large Hispanic populations — the diagnosis and misdiagnosis of speech sound disorders in bilingual Latino children.

"School-based speech-language pathologists, or SLPs, are required to provide culturally competent services to all children, including those who speak both English and Spanish," Fabiano-Smith says. "They face a great clinical challenge: accurate identification of speech sound disorders in children who speak two languages."

While there are many standardized tests that SLPs can use for monolingual children, there is only one for bilingual children. Fabiano-Smith is building on her earlier research, which was funded by the National Institute on Child Health and Human Development, to develop tools that SLPs need to accurately diagnose speech sound disorders in Latino children.

Fabiano-Smith and her research team partnered with Tucson's Sunnyside Unified School District, which is approximately 82 percent Latino, and are continuing their work with 3- and 4-year-olds enrolled in preschool programs. The children are recorded while being asked to identify pictures; the recordings are then analyzed to determine where the children are having problems with their speech sound production.

If a bilingual child is not producing English speech sounds exactly like their monolingual peers, they may not have a disorder. They may just need extra help with English language skills, Fabiano-Smith says.

"SLPs have some confidence when assessing bilingual children whose primary language is English, but lack confidence when assessing bilingual children whose primary language is Spanish," Fabiano-Smith says.

This can lead to under- and over-diagnosis of speech sound disorders, and both scenarios have serious consequences. The under-diagnosis of speech sound disorders in bilingual children creates a health disparity that can lead to problems like aggressive behavior, hyperactivity and poor academic performance.

Over-diagnosis can happen when SLPs use standardized tests that are normalized on monolingual English-speaking children. If a bilingual child is having a tough time with proper speech sounds, they may not have a disorder, they may just need extra help with English language skills. This can create an educational disparity when Latino children are pulled out of class for unnecessary speech therapy.

In addition to the educational and social costs, Fabiano-Smith notes the clinical problem has financial consequences.

“The cost of special services is driven more by the number of children served than the cost of the service itself," she says "It costs the public-school system an additional $10,000 per student, per year who are incorrectly classified as speech-impaired.”

The NIH grant will allow Fabiano-Smith to use the data collected in her first study to develop an evidence-based assessment procedure for identifying bilingual children with speech disorders. Her goal is to create a test for bilingual children that is both accurate and efficient.

"We are in danger of misdiagnosing a generation if this problem is not solved now," Fabiano-Smith said.

"As a land-grant institution, the University of Arizona is deeply invested in the education of people of all ages, and in ensuring that all children have the support they need to achieve their dreams," said UA President Robert C. Robbins. "The UA's status as a Hispanic-Serving Institution is driven by our commitment to the academic success of every member of our community, and Dr. Fabiano-Smith’s work with bilingual children is a vital contribution to this part of our mission. I am very excited by what this grant will enable."