LM321 - Addressing Barriers to Intervention Through In-House Earmold Manufacturing

Abstract:
Many infants who do not pass newborn hearing screening do not receive appropriately fit amplification by 6-months, thus not meeting intervention goals. Further, once fit with devices, infant growth rates require frequent earmold remakes to maintain consistent sound delivery. Delays in traditional earmold acquisition processes can present as barriers to consistent amplification use. In-house earmold manufacturing using 3-D scanning and printing technology can allow earlier and more consistent access to appropriately fit amplification. This presentation will focus on the rationale, process, and future considerations for the use of in-house 3-D earmold printing to improve access to amplification.

Summary:
Thirty years after the National Institutes of Health Consensus Development Conference on Early Identification of Hearing Loss, almost 98% of newborns in the US are screened for hearing loss at birth (Centers for Disease Control and Prevention (CDC), 2022).  However, many infants who do not pass their newborn hearing screening do not complete the early hearing detection and intervention EHDI process by 6 months.  To meet the EHDI goals of diagnosis by 3 months of age and early intervention enrollment by 6 months of age (JCIH, 2007, 2019) will require identification of barriers to diagnosis and intervention, followed by innovative solutions to improve outcomes for infants and families. 

In evaluating the patient care pathway, reducing the time from diagnosis of hearing loss to fitting of custom amplification solutions was identified as an opportunity to increase healthcare efficiency and decrease time to intervention.   The current hearing aid ear mold manufacturing process can take anywhere from 2 to 4 weeks to fit a hearing aid on an infant and during the pandemic this time expanded to 4 to 6 weeks due to supply chain interruptions.  In addition to prolonging the time from diagnosis to initial fitting of custom hearing solutions, this delay results in decreased use time for infants and young children with rapidly growing ear canals before the custom product must be replaced. 

In 2020, the Callier Center for Communication Disorders began to investigate the possibility of using 3D printing for in-house earmold manufacturing to reduce the time between diagnosis of hearing loss and fitting of amplification.  The Callier Center’s proof of concept suggested in house earmold manufacturing of custom earmolds with 3D printing is feasible. Pilot data indicate the process has not only reduced the time between diagnosis of hearing loss and intervention but that it has also improved consistency of device usage for infants and children with reduced down time due to earmold remakes.

Steps involved in the earmold manufacturing process include impression digital scanning, earmold design and casting. Following 3-D printing, resin cleaning, curing, and silicone fill and finishing are required. Each step of the process was designed with accuracy, patient safety, and in clinic implementation considerations. Proof of concept testing and process correction factors were completed during the Summer of 2022 utilizing REAT testing with custom earplugs and duplicate earmold ordering from current manufacturers for comparison.

Data collection from clinicians and parents reexamines turnaround time, compliance for follow-up, device usage, and quality assurance factors. Benefits and challenges during the first year in production of in-house earmolds will be discussed as well as visual demonstrations and descriptions of the procedures.

Use of 3-D printing for improved access to custom earmolds for hearing solutions has expanded beyond early intervention to benefit other patient populations within in our clinic including low-income patients, individuals who have significant visual difficulties, individuals with anatomical differences as well as other, difficult to fit adult populations, and children with transient living situations.