Background: Early hearing aid experiences are highly dynamic and heterogeneous. Fine-grained temporal dynamics remain poorly understood, particularly whether early hearing aid adaptation reflects time-dependent processes or heterogeneous trajectories driven by user behavior and perceived benefit. This study examined whether listening outcomes improve over the first two weeks of first-time hearing aid users’ experience and whether distinct early adaptation subtypes exist. Method: Fifty-three adult hearing aid users (mean age = 68.6 years, female = 72%) completed Ecological Momentary Assessments (EMA) twice daily over a 14-day period following hearing aid fitting (N = 1,133 observations) as a part of an ongoing clinical trial. Single item of hearing difficulty, hearing aid usage, comfort, performance, satisfaction, and contextual factors were administered via the SEMA3 EMA software. Multilevel mixed-effects models assessed within-person temporal and contextual effects, latent class growth analysis (LCGA) identified adaptation trajectories, and multinomial logistic regression examined predictors of class membership. Results: A significant temporal increase was observed for comfort (β = 0.03, adj p = 0.01, ω² ≈ 0.10), indicating gradual physical adaptation over time after adjusting for age and sex. In contrast, temporal effects were not significant for hearing difficulty (p = 0.33), performance (p = 0.53), satisfaction (p = 0.59), or hearing aid usage (p = 0.17). No significant time of day effects (AM vs PM) were observed across outcomes (all p > 0.05). Together, these findings indicate that temporal factors alone did not drive early adaptation. Instead, within-person behavioral and experiential 1 IHCON 2026 factors showed robust associations with outcomes, with greater hearing aid usage (β = -0.69, adj p <0.001) and perceived performance (β = -0.70, adj p < 0.001) associated with reduced hearing difficulty. LCGA identified a two-class solution, revealing distinct adaptation subtypes: an improving group (66%) characterized by decreasing hearing difficulty over time, and a non-improving group (34%) exhibiting stable difficulty. Multinomial regression showed that higher average self-reported hearing aid usage (β = -6.80, adj p = 0.02) and perceived performance (β = -5.19, adj p = 0.02) significantly reduced the likelihood of belonging to the non-improving group, whereas other demographic and baseline audiological characteristics were not significant predictors. Conclusions: Early hearing aid adaptation is not uniformly time-driven but reflects heterogeneous trajectories driven by hearing aid use and perceived performance. Although physical comfort improves over time, reductions in perceived difficulty are limited to approximately two-thirds of users.