Background: Cisplatin is one of the most ototoxic drugs in use, causing permanent, bilateral sensorineural hearing loss in substantial numbers of patients, with many developing permanent tinnitus. Few studies, however, have systematically quantified the entire range of hearing loss (0.25-12 kHz) in patients given homogenous cisplatin-based chemotherapy using comprehensive audiometric methods and patient-reported outcomes. Methods: We performed detailed audiometry for 359 patients enrolled in an ongoing multi-center clinical study of TCS given cisplatin-based chemotherapy at centers in North America (NCI R01CA157823). Air conduction thresholds were measured at frequencies ranging from 0.25-12 kHz and bone conduction thresholds from 0.25-4 kHz in each ear. Results: Median age at evaluation was 39 years (range 20-63 years) with approximately 43% previously having seminomas and 57% nonseminomas. Over 90% of patients were white, while most (66%) had Stage II or III disease. Chemotherapy consisted largely of standardized regimens and doses, i.e., BEP X 3 (51%), EP X 4 (19%), slight modifications (27%) of either regimen, or VIP (3%). We identified 85.2% patients with hearing loss ( > 20 dB) at any frequency for either ear. Of these, 48.7% had conductive hearing loss and 39.2% showed evidence for noise-induced hearing loss for either ear. For each patient, we compared the area under the air conduction audiogram curve (AUC) (mean of both ears) to the expected AUC for this age group. Patients with AUCs greater than respective normal-aging AUCs were considered to have cisplatin-induced hearing loss (32.6%). Measured on a Likert scale from 0-3, 39.2% and 29.8% reported tinnitus and hearing loss (score 1+), respectively. The audiogram AUC correlated strongly with both self-reported tinnitus (R = 0.31, P = 1.1e-08) and self-reported hearing loss (R = 0.36, P = 7.0e-11). Conclusions: Cisplatin-induced ototoxic phenotypes affect 29-40% of TCS in this North American study. Future analytic investigations will focus on genetic and mechanistic investigations to facilitate the development of predictive, management and preventive efforts for ototoxicity in high-risk patients.