The research that we perform through the Children's Communication Center is focused on being:

  • Inter-disciplinary, drawing from the experiences and knowledge of clinicians and scientists with varied backgrounds;
  • Patient-centered, ideally with direct benefit to participants;
  • Inclusive, with an emphasis on understanding diverse populations and their unique needs.


Preschool Hearing Screening 

Community-based preschool hearing screening is a critical system for early identification of hearing loss in children during the gap between universal newborn hearing screening and school- and pediatrician-based hearing screening at age 4. We collaborated with the San Francisco Department of Public Health to study over 8,000 children over 7 years in their preschool hearing screening program. We found that the gold standard pure-tone-audiometric screening actually is unable to be used for many 3-year-olds, and that implementation of a second-stage otoacoustic emission backup is effective in improving screening and identification rates.

Brodie KD, David AP, Kriss H, Chan DK. Outcomes of an Early Childhood Hearing Screening Program in a Low-Income Setting. JAMA Otolaryngol Head Neck Surg. 2022 Apr 1;148(4):326-332. doi: 10.1001/jamaoto.2021.4430. Erratum in: JAMA Otolaryngol Head Neck Surg. 2022 Nov 1;148(11):1081-1082. PMID: 35175312; PMCID: PMC8855310.

Cedars E, Kriss H, Lazar AA, Chan C, Chan DK. Use of otoacoustic emissions to improve outcomes and reduce disparities in a community preschool hearing screening program. PLoS One. 2018 Dec 10;13(12):e0208050. doi: 10.1371/journal.pone.0208050. PMID: 30532159; PMCID: PMC6287830.


Congenital CMV-associated Hearing Loss

Infection during pregnancy with cytomegalovirus (CMV) is most common acquired cause of hearing loss in newborn babies. We are working with local birthing hospitals and local state agencies to standardize testing protocols for CMV infection in babies who do not pass their newborn hearing screens.



All children seen in the multidisciplinary Hearing and Communication Clinic are administered a standardized assessment in each of the multiple specialty domains. Comprehensive, multi-dimensional, longitudinal tracking of these assessments in a hearing-loss database will allow the analysis of the complex interplay between the different aspects of care for children with hearing impairment. Through this information, we hope to learn how hearing impairment affects children and families, and how best to help families learn to help their child listen and communicate. 


Teletherapy to Address Disparities in Language Development

The “Teletherapy to address language disparities in deaf and hard-of-hearing children” study is a randomized, unblinded multicenter trial funded by The Patient Centered Outcomes Research Institute (PCORI). The study is designed to find out if improving access to teletherapy - online delivery of speech-language therapy via live video conferencing - for children who are deaf or hard-of-hearing (D/HH) can reduce disparities in language outcomes seen between children from higher- and lower-income homes. Children ages 0 - 27 months that have a confirmed hearing loss in one or both ears and speak either English and Spanish at home may be eligible for the study. Enrolled subjects are required to complete three speech-language assessments over 18 months to measure the hearing function, speech, language and quality of life. 1/3 of subjects will be randomized to receive access to supplemental teletherapy. Compensation will be provided upon completion of each assessment.

For more information, please visit UCSF Clinical Trials or PCORI study page.


Language EnviroNment Analysis (LENA)

The LENA (Language Environment Analysis) system is a language and audio environment tracking tool designed to provide parents, clinicians, and researchers with information about a child’s language environment and language development. A full day of talk is captured by a small child-safe recorder worn in a comfortable vest or shirt as LENA records all sounds within 6 feet. LENA recording generates a report detailing a child’s speech maturity, their daily exposure to TV and electronic noise, and the number of adult words and conversations they had with a caregiver. To learn more, please contact Jenny Stephans, Program Coordinator, at 415-353-2012.

Sola AM, Brodie KD, Stephans J, Scarpelli C, Chan DK. Tracking Home Language Production and Environment in Children Who Are Deaf or Hard of Hearing. Otolaryngol Head Neck Surg. 2022 Jan;166(1):171-178. Doi: 10.1177/01945998211013785. Epub 2021 May 25. PMID: 34032520.


Understanding Hearing-Loss Genetics in Diverse Populations

Hearing loss is the most common congenital sensory impairment, with 1:500 children born D/HH. Over 50% of childhood sensorineural hearing loss (SNHL) is estimated to have a genetic etiology. Hearing-loss gene-panel testing (HL-GPT) is the most impactful and effective etiologic test for childhood SNHL. Genetic diagnosis for hearing loss facilitates hearing intervention, informs prognosis, provides early identification of syndromic associations, enables family counseling, and is the foundation for impending gene therapy. However, racial/ethnic disparities in hearing-loss genetic testing access and outcomes are enormous. Because so few under-represented minority (URM) individuals have been enrolled in hearing-loss genetics studies, genetic testing for hearing loss is underpowered to yield an informative diagnosis. We aim to address disparities in hearing loss genetics by re-classifying variants that have been identified in URM children with SNHL to help better interpret and utilize their HL-GPT results. This project will also contribute to the efforts underway to expand clinical variant databases, making them more equitably representative across racial and ethnic groups.

Rouse SL, Florentine MM, Taketa E, Chan DK. Racial and ethnic disparities in genetic testing for hearing loss: a systematic review and synthesis. Hum Genet. 2022 Apr;141(3-4):485-494. Doi: 10.1007/s00439-021-02335-7. Epub 2021 Sep 7. PMID: 34494120; PMCID: PMC9035011.

Florentine MM, Rouse SL, Stephans J et al. Racial and ethnic disparities in diagnostic efficacy of comprehensive genetic testing for sensorineural hearing loss. Hum Genet. 2022 Apr;141(3-4):495-504. Doi: 10.1007/s00439-021-02338-4. Epub 2021 Sep 13. PMID: 34515852; PMCID: PMC9035005.

Liao EN, Taketa E, Mohamad NI, Chan DK. Outcomes of Gene Panel Testing for Sensorineural Hearing Loss in a Diverse Patient Cohort. JAMA Netw Open. 2022 Sep 1;5(9):e2233441. Doi: 10.1001/jamanetworkopen.2022.33441. PMID: 36166228; PMCID: PMC9516276.

Brodie KD, Liao EN, Florentine MM, Chan DK. Impact of Genetic Testing on Hearing Interventions. Laryngoscope. 2022 Sep 27. Doi: 10.1002/lary.30409. Epub ahead of print. PMID: 36165585.

Brodie KD, Moore AT, Slavotinek AM, Meyer AK, Nadaraja GS, Conrad DE, Weinstein JE, Chan DK (2020). Genetic Testing Leading to Early Identification of Childhood Ocular Manifestations of Usher Syndrome. Laryngoscope. Oct 28. PMID: 33111992.

Chan DK, Chang KW (2014). GJB2-associated hearing loss: systematic review of worldwide prevalence, genotype, and auditory phenotype. Laryngoscope 124(2):E34-53. doi:10.1002/lary.24332.


Disparities in Pediatric Hearing Health Access and Outcomes

Timely identification and intervention of childhood hearing loss is required to prevent permanent speech, language, and cognitive delays in children who are deaf or hard of hearing. Many families of children who are D/HH face additional challenges that intersect with and compound their challenges of raising a D/HH child. These challenges can involve navigate complex clinical and educational systems and well as cultural and personal identities. The CCC engages in mixed-methods studies to better understand the challenges that families face, using quantitative methods to understand population-level trends as well as focused qualitative techniques through structured, culturally congruent interviews with families and healthcare providers to learn about lived experiences that can be unique as well as shared across communities. 

Florentine MM, Le Clec’h S, Upton SM, Scarpelli C, Carr JP, Chan DK. Disparities in Speech and Language Delay Among Children With Aural Atresia. Ear Hear. 2022 Sep-Oct 01;43(5):1574-1581. Doi: 10.1097/AUD.0000000000001218. Epub 2022 Mar 23. PMID: 35319519.

Bhatia P, Rems-Smario J, Jaradeh K, K Chan D. Childhood Hearing Health and Early Language Exposure: A Culturally Sensitive Approach. Adv Pediatr. 2022 Aug;69(1):23-39. Doi: 10.1016/j.yapd.2022.04.003. Epub 2022 Jun 21. PMID: 35985712.

Florentine MM, Strohl MP, Benvenuti CS, Eiseman M, Ho M, Meyer AK, Scarpelli C, Chan DK. Access Challenge Index: A Novel Disparity Measure Predictive of Language Outcomes in Deaf/Hard-of-Hearing Children. Otolaryngol Head Neck Surg. 2022 Jul;167(1):170-177. doi: 10.1177/01945998211040017. Epub 2021 Sep 7. PMID: 34488501.

Vukkadala N, Perez D, Cabala S, Kapur C, Chan DK. Linguistic and behavioral performance of bilingual children with hearing loss. Int J Pediatr Otorhinolaryngol. 2018 Sep;112:34-38. doi: 10.1016/j.ijporl.2018.06.020. Epub 2018 Jun 12. PMID: 30055736.

Su BM, Park JS, Chan DK. Impact of Primary Language and Insurance on Pediatric Hearing Health Care in a Multidisciplinary Clinic. Otolaryngol Head Neck Surg. 2017 Oct;157(4):722-730. doi: 10.1177/0194599817725695. Epub 2017 Sep 12. PMID: 28895463.