IMPORTANCE: Existing patient-reported outcome measures of tinnitus assess the severity and disability retrospectively, which may result in adequate reliability, but cannot capture the fluctuating and individualized nature of tinnitus. Experience sampling may provide an alternative. OBJECTIVE: To use an ecological momentary assessment (EMA) to measure tinnitus disability and associated constructs. DESIGN, SETTING, AND PARTICIPANTS: Forty adults with tinnitus provided self-report of their tinnitus bother using 5 questions measured by EMA, as well as standard retrospective outcome measures. In this 6-week longitudinal observational study conducted from July 15 to December 22, 2014, participants provided EMA data for 2 weeks (part 1); then after a 2-week break, they provided EMA data for an additional 2 weeks (part 2). A text message with a link to the EMA survey was sent for a total of 56 assessments during each 2-week assessment period. Ecological momentary assessment responses were evaluated using multilevel confirmatory factor analysis to assess the fluctuating nature of bothersome tinnitus across the group and within the pool of individuals over time. MAIN OUTCOMES AND MEASURES: Ecological momentary assessment questions measured tinnitus disability and associated constructs. Compliance in each study part was assessed based on response rates. The Tinnitus Functional Index and the Overall Global Rating of Bother Scale were assessed at the beginning and end of each 2-week assessment period to explore the effect of the frequent EMAs on the perceived level of bother from tinnitus. RESULTS: Of the 40 participants in the study (10 women and 30 men; mean [SD] age, 60.0 [10.5] years), the median survey response rate was high (49 responses to 56 surveys sent [88%] for part 1 and 47 responses of 56 surveys sent [84%] for part 2). The latent factor identified by the 2-level confirmatory factor analysis models demonstrates that within-individual tinnitus bother, loudness, and stress vary together over time. In addition, tinnitus bother, feeling, and stress symptoms all vary together across individuals, which means that bother and stress covary strongly both across time and across individuals. CONCLUSIONS AND RELEVANCE: Ecological momentary assessment evaluates the moment-to-moment perception of tinnitus and the effect of emotional and environmental factors, which suggests that it is a superior tool to measure tinnitus outcomes compared with standard retrospective self-reports. Taken together, information from emotional and environmental factors can be summarized in an underlying (latent) factor that represents a vulnerability to bothersome tinnitus and that can be used to comprehensively describe the tinnitus experience. Momentary variability in tinnitus bother is strongly associated with levels of perceived stress. © 2017 American Medical Association. All rights reserved.