Hearing loss is the most common sensory impairment in children. If hearing loss is not identified and managed with hearing aids and educational interventions, it often leads to permanent speech, language and developmental delays. Because of this, many national systems have developed to enable early detection and intervention for childhood hearing loss. These include universal newborn hearing screening and broad-based hearing screening at 4-year-old pediatrician well-child checks and upon school entry in kindergarten or first grade. 

There is, however, a large gap in hearing screening between birth and age 4; this coincides with the time when hearing, speech and language are developing the fastest. Preschool hearing screening can potentially fill this screening gap, but the most effective method for preschool hearing screening is unknown. Behavioral testing, in which children respond to hearing a sound, are the gold standard for hearing screening, but many 3-year-olds cannot complete the test at all. For preschools, then, a second, nonbehavioral test is needed for these children. Nonbehavioral testing with otoacoustic emissions can permit hearing screening without needing the child to cooperative. It is highly effective as a second-stage screen for children who are not able to be tested behaviorally, but its effectiveness as a standalone, single-stage screen in community-based preschools has yet to be evaluated. 

In this study, the research team will determine whether the simple, single-stage otoacoustic emission screen performs at least as well as the gold-standard, two-stage pure-tone plus otoacoustic emission method. If the single-stage screen is found not inferior to the two-stage screen, the team will be able to conclude that the inherently simpler single-stage screen would be an ideal choice to use for broad-based preschool hearing screening. This knowledge will help preschools decide what hearing screening method to use, and therefore help parents of preschoolers know that they are being identified with hearing loss in the best possible way. Study findings will also help national organizations update their guidelines for preschool hearing screening so that these best practices can be implemented across the United States.

This study will recruit 28,000 preschool students, ages 2-5, across Northern California, and compare the effectiveness of two-stage, pure tone plus otoacoustic emission screening versus single-stage, otoacoustic emission-only screening. Enrolled children will be considerably diverse, with multiple home languages, geographic locations (urban, suburban, and rural) and subjects across multiple income levels included. As a primary outcome measure, the research team has chosen the outcome that is most important to parent and professional stakeholders: the percentage of children screened identified with any hearing loss. In addition to this primary outcome measure, the team will test other, secondary outcome measures: the success rate of the screening methods, the rate at which children are referred for further definitive hearing testing and the identification rates of specific subcategories of hearing loss.

The study engaged many stakeholders to help design, conduct and distribute the study findings to have maximal impact. These include individuals directly involved in preschool hearing screening itself: parents of children who were identified with hearing loss in the preschool age, leaders of preschool hearing screening programs, and individuals responsible for the follow-up testing and management after a failed hearing screen. The research team also engaged members of multiple national organizations that determine hearing screening policy to help implement study findings into national guidelines and policy.