For the past three years, Gabriella Musacchia, PhD, assistant professor of audiology, Jiong "Joe" Hu, PhD, assistant professor of audiology, and their research team have traveled to Nanjing, China, to assess at-risk infants for early signs of hearing impairments. Research shows that early detection and intervention can help children with hearing loss develop better language skills later in life. This international collaboration includes researchers from the Stanford University School of Medicine and Nanjing Maternal and Child Health Hospital, which is associated with Nanjing Medical University.

Pacific doctor of audiology students had the opportunity to join the research team, where they played a critical role in recording data and examining patient cases. "It is always our priority to have students involved in projects that are on the forefront of auditory research," said Dr.Hu. "Students will not only experience the process of research, but will also learn from experts in this field."

During the two-week trip, the research team evaluated the auditory processing development in two groups: infants born with jaundice and healthy infants. Jaundice occurs when the baby's blood contains excess bilirubin, a yellow pigment of red blood cells. This causes a yellow-hued discoloration to the skin and eyes. If untreated, jaundice causes liver and brain damage. Research suggests that jaundice is also a risk factor for Auditory Neuropathy Spectrum Disorders.

The research team measured stimulated responses using the speech-evoked frequency-following response (FFR) method, a test for speech functional processing. Team members also employed the Auditory Brainstem Response (ABR), one of two methods used as part of the universal hearing screening program.

The FFR method uses the speech unit of a consonant-vowel combination, specifically the syllable "da," which is widely used in English and in Mandarin Chinese words, such as 大 (big) and 打 (hit). Stimuli parameters for the ABR method followed standard clinical parameters such as a brief click or tone beep. Both sounds were presented at equal sound levels.

The FFR method proved to be a promising measure to better understand hearing loss and its effect in infants with newborn jaundice. Their research found that infants with jaundice have a less robust response to speech sounds. Further testing also revealed that after phototherapy treatment for jaundice, the infant's response increased when given the same hearing screening using the FFR method. These results would have either been undetected or labeled as low-risk using the ABR method.

"While the ABR method has been widely used to assess auditory functions, there is reason to think the FFR method may be better suited to identify the precise neural transmission abilities of the auditory nervous system," said Dr. Musacchia. This discovery further supports the use of FFR in clinical settings for audiologists and neonatologists.

Researchers are making breakthroughs by taking cues from Mother Nature. "We found it intriguing that we might be able to use the mother's voice rather than clicking signals as a hearing screen test," said Vinod K. Bhutani, MD, professor of pediatrics at the Stanford University School of Medicine. "Our concurrent research that promotes skin-to-skin care, also known as kangaroo mother care, aligns nurturing processes to our research objectives."

"Hearing is an international issue," Dr. Musacchia said. "This collaboration is important because it gives our students a breadth of knowledge and context for what we do. It also supports the department's mission to advance the profession and create audiologists who are global citizens."

Qin Hong, associate professor at Nanjing Medical University and associate chief physician at Nanjing Maternal and Child Health Hospital, served as a visiting scholar in Pacific's Department of Audiology from January to June 2019. "A close relationship and deep collaboration can certainly benefit both parties and will, in turn, form the forefront of international collaboration in providing hearing health care," she said.

about the author

Dua Her  

Dua Her is the Director of External Relations and Professional Development at Pacific's Thomas J. Long School of Pharmacy.