Eargo, Inc. has developed a hearing aid that contains self-fitting gain software that allows adults with mild-to-moderate hearing loss to test their hearing sensitivity and program hearing aids to match their measured hearing loss. Traditionally, hearing aids are custom programmed by a hearing health professional based on a professional hearing test. This technology has the potential to improve affordability and accessibility of hearing aids for adults with mild-to-moderate hearing loss. We propose to validate Eargo's self-fitting software in a clinical trial comparing self-fitting hearing aid outcomes to the same hearing aid fit by a professional following usual clinical best practice for fitting hearing aids.

The study will recruit 30-50 adults age 18 and over with mild-to-moderate hearing loss in both ears. We will aim to recruit a sample with roughly equal number of males and females and new and experienced hearing aid users (defined by any hearing aid use within the previous 6 months). Hearing loss will be measured using the results of a standard clinical hearing test.

We will use a within-subject, crossover design in which all participants will complete both field trial hearing aid conditions (self-fit and clinically fit hearing aids). The order of the field trials will be randomized across participants to account for any potential order effects. After each field trial, participants will visit the lab to complete study outcome measures, including hearing aid benefit, subjective sound quality, and speech in noise intelligibility testing.

Inclusion Criteria:

• mild to moderate hearing loss ability to follow written directions,

Exclusion Criteria:

• inability to use software during first visit

Participants will be randomly assigned and will not know which fit is first.