Project Summary

PCORI has identified hearing loss as an important research topic. Patients, caregivers, clinicians, and others want to learn: How do treatments for mild to moderate age-related hearing loss, such as hearing aids and other supports, compare? To help answer this question, PCORI launched an initiative in 2019 on Treatment Options for Age-Related Hearing Loss. The initiative funded this research project and others.

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

Hearing loss is common in older adults. Hearing aids can help, but they can be expensive. Doctors often suggest that adults get hearing aids for both ears. But doctors don’t know if using two hearing aids is better than one for most older adults with mild to moderate hearing loss.

In this study, the research team wants to learn if one hearing aid is as effective as two at improving hearing in older adults with mild to moderate hearing loss.

Who can this research help?

Results may help patients with age-related hearing loss and their doctors when deciding whether to use one hearing aid or two.

What is the research team doing?

The research team is enrolling 350 adults ages 50 and older who are seeking initial treatment for hearing loss at two clinics in North Carolina and Tennessee. All patients have mild to moderate hearing loss in both ears and are using hearing aids for the first time.

The research team is assigning patients by chance to one of two groups. In the first group, patients use hearing aids in both ears. In the second group, patients use a hearing aid in one ear. Patients buy the hearing aids themselves. After three and six months, patients can change the number of hearing aids they are using or return their hearing aids for a refund.

Patients are completing hearing function tests before they start the study and three months after the hearing aid fittings. Patients also complete surveys before they start the study and again after three and six months. The surveys ask patients about

  • How much they benefit from their hearing aids
  • Satisfaction with their hearing aids
  • Hearing-related quality of life
  • How much they use their hearing aids
  • Other hearing-related outcomes

The research team is conducting focus groups with patients to learn about their experiences with and preferences for hearing aids.

Patients with hearing loss, family members, doctors, audiologists, and representatives from hearing aid makers are helping the research team design the study.

Research methods at a glance

Design Element Description
Design Randomized controlled trial
Population 350 adults ages 50 and older with mild to moderate age-related hearing loss in both ears who are using hearing aids for the first time
  • Bilateral hearing aids

  • Unilateral hearing aid


Primary: hearing aid benefit

Secondary: in situ hearing aid benefit, speech-in-noise performance, auditory working memory, hearing aid satisfaction and experiences, hearing aid use, hearing-related quality of life, hearing disabilities, hearing aid expectations, global hearing aid outcomes, number of hearing aids chosen

Timeframe Timeframe Length of follow-up for collecting data on primary outcomes. View Glossary 6-month follow-up for primary outcome

Project Information

Sherri L. Smith, AuD, PhD
Duke University
Evaluation of Unilateral versus Bilateral Hearing Aids for the Treatment of Age-related Hearing Loss

Key Dates

January 2020
February 2025

*This project was initially titled "Addressing the Clinical Dilemma and Patient Preference for Unilateral versus Bilateral Hearing Aids"


Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: September 26, 2023