DESCRIPTION: Hearing loss, and the resulting consequences of it, is an important problem that affects all humans. No person is exempt from the process of aging or the eventual impact it has on the ear-brain system. This point is noteworthy because the portion of the population aged 65 years and older is increasing at a faster rate than the total population. Twenty percent of the population is predicted to be 65 years or older by 2030 and between 35% and 50% will likely report having presbycusis, a sensory impairment that is treated primarily through the use of hearing aids (HA). A major problem, however, is that HA use among people with hearing loss is not prevalent (approximately 25%) and only half of those users report being satisfied with their aided performance in noise. Despite careful efforts to verify that hearing aids (HA) are fitted appropriately in the clinic, there is little evidence to support that current practices result in successful outcomes. Our hypothesis is that successful HA use depends, in part, on the signal-to-noise (SNR) ratio being delivered to a person's auditory system by their HA as well as a person's own ability to neurally encode speech in noise. Our overall project goal is to identify patient- and device-centered variables that contribute to HA success so that related outcome measures can be developed and applied in clinical settings. Two expected predictors of real-world HA success are the individual's threshold for speech in noise (SNR-50) as well as the SNR at the output of the HA.