Research (R)
Bryan M. Wong, AuD
PhD Candidate
University of Arizona
University of Arizona, Arizona
Disclosure(s): No financial or nonfinancial relationships to disclose.
Nicole Marrone
Disclosure(s): No financial or nonfinancial relationships to disclose.
Kasi Kiehlbaugh
Disclosure(s): No financial or nonfinancial relationships to disclose.
Audiologists rely on third-party manufacturers to supply custom earmolds and hearing aid parts, which can create unintended barriers for patients pursuing care. The advancement of 3D printing technology, standardly used in the hearing health industry, has made it accessible for local clinical settings. This study aims to compare in-house 3D printed earmolds to professionally manufactured earmolds in a group of normal hearing individuals. The research involves comparing production, physical, objective acoustic, and subjective comfort measures between professionally-made earmolds and in-house 3D printed earmolds. Implementing 3D printing locally could reduce geographic barriers, time, and costs for patients pursuing hearing healthcare.
Summary:
Rationale/
Purpose: Audiologists rely on third-party manufacturers to supply custom earmolds and hearing aid parts, which can create unintended barriers for patients pursuing care. The advancement of 3D printing technology, which has been standardly used by the hearing health industry for decades, has made it accessible for local clinical settings. The purpose of this study is to compare production variables, physical measures, objective acoustic measures, and subjective comfort measures between in-house 3D printed earmolds and professional third-party manufactured earmolds.
Methods:
A randomized controlled, three-arm, cross-over trial will be conducted. Participants, aged 18-89 years, with normal hearing thresholds (≤ 25 dB HL) from 250 to 8000Hz will be recruited for this study. Additional inclusion criteria includes English as primary spoken language, no history of learning disability or cognitive impairment, and no history of neurologic impairment or head injury.
There are three phases of this study. The first session involves obtaining informed consent, ensuring potential participants meet eligibility criteria, and taking a custom ear impression of one ear. Next, ear impressions are 3D scanned, edited into an earmold, and then 3D printed. The original ear impression will then be sent to a professional third-party manufacturer to fabricate a control earmold. Participants will also be randomly assigned to one of three study arms, each with a different initial earmold material type. Lastly, participants will be fit with each earmold attached to a BTE hearing aid and production measures, objective acoustic measures, objective physical measures, and subjective comfort ratings will be collected. Protocol was approved by the IRB and is registered on clinicaltrials.gov (NCT05725824).
Results &
Conclusions:
Data collection is in progress and near completion. Following guidelines for authors, data analysis will be completed by February 15th, 2024.
The main statistical analysis includes a repeated measures, within-group, ANOVA. A power analysis using G*Power 3.1 revealed that a sample size of 17 to 26 subjects will provide 80-95% power to detect a medium effect size of 0.55 for Cohen’s D using a .05 alpha level. These values were selected based on a review of 32 meta-analyses that examined effect size distributions in speech, language and hearing research (Gaeta & Brydges, 2020).
Importance of Work:
Three-dimensional printing has been standardly used by manufacturers for decades, however its adoption and implementation has not reached the local clinical level. This is not the case for dentistry/orthodontics, which has widely adopted and successfully implemented 3D printing technology to make custom mouth guards, retainers, and surgical guides for their clients in-house. This technology employed in a local audiology clinical setting has the potential to help reduce aspects of hearing healthcare disparities related to geographic barriers, time, and cost.
Innovation:
Findings may lead to a novel method of hearing healthcare delivery that has the potential to increase overall hearing healthcare accessibility, generate an additional revenue source for audiology clinics, and create new telehealth applications for marginalized populations worldwide.