Background: Although pure-tone audiometry is the gold standard to evaluate hearing loss (HL), patient-reported outcomes are practically more time and cost effective. However, no data exist on factors associated with discrepancies between patient-reported and audiometrically-defined HL in adult-onset cancer survivors after cisplatin-based chemotherapy (CBCT); and few comprehensive assessments of factors associated with audiometrically-defined HL have been conducted. Methods: A total of 1,410 testicular cancer survivors (TCS) ≥6 months post-CBCT completed comprehensive audiometric assessments (0.25-12 kHz) and detailed questionnaires of sociodemographic, clinical, and health behaviors. Audiometrically-defined HL severity was defined using American Speech-Language-Hearing Association (ASHA) criteria. Multivariable multinomial logistic regression identified factors associated with discrepancies (overestimation and underestimation vs. concordance), between patient-reported and audiometrically-defined HL and multivariable ordinal logistic regression evaluated factors associated with the HL severity. Results: Overall, 34.8% of TCS self-reported HL, while 77.8% had audiometrically-defined HL. Among TCS without tinnitus, those with audiometrically-defined HL at only extended high frequencies (EHFs) (10-12 kHz) (17.8%) or at both EHFs and standard frequencies (0.25-8 kHz) (23.4%) were significantly more likely to self-report HL than those with no audiometrically-defined HL (8.1%) (OR = 2.48; 95%CI, 1.31-4.68 and OR = 3.49; 95%CL,1.89-6.44, respectively). Older age (OR = 1.09; P< 0.0001), absence of prior noise exposure (OR = 1.40; P= 0.02), and mixed/conductive HL (OR = 2.01; P= 0.0007) were associated with greater underestimation of audiometrically-defined HL severity. Hearing aid use (OR = 0.18; P= 0.003) and higher education (P= 0.004) were associated with less underestimation of audiometrically-defined HL severity, while tinnitus was associated with greater overestimation (P< 0.0001). Older age (OR = 1.13; P< 0.0001), cumulative cisplatin dose ( > 300 mg/m^2, OR = 1.47; P= 0.0001), and hypertension (OR = 1.80; P= 0.0007) were associated with greater ASHA-defined HL severity, whereas post-graduate education (OR = 0.58; P= 0.005) was associated with less severe HL. Conclusions: Discrepancies between patient-reported and audiometrically-defined HL after CBCT are associated with several factors including age, education, tinnitus, prior noise exposure, use of hearing aids, and conductive HL. Understanding these factors will help clinicians to better interpret self-reported HL as a surrogate for audiometric assessments. For survivors who self-report HL, but have normal audiometric findings at standard frequencies, referral to an audiologist for additional testing and inclusion of EHFs in audiometric assessments, should be considered.