Background <p>Hearing is essential for communication, social interaction, and learning. Approximately 1 in 500 newborns have congenital hearing loss, with the prevalence being higher in low- and middle-income countries. This study aimed to report the prevalence of childhood hearing loss in Bangkok, assess associated factors, and evaluate the performance of different school-based screening approaches.</p> Methods <p>This cross-sectional study was conducted from July 2023 to March 2024. Pupils were randomly recruited from nine primary schools in central Bangkok. Hearing screening was conducted by schoolteachers and audiologists. The teachers conducted initial screening using a hearing screening form, followed by professional screening procedures performed by audiologists, including otoscopy, tympanometry, and audiometric screening.</p> Results <p>A total of 407 pupils participated in this study (mean age 7.9 years, SD 0.8). No significant relationships between demographic factors and hearing status were revealed. Audiometric screening identified hearing impairment in 6.1% of pupils, including 2.9% with bilateral and 3.2% with unilateral impairment. Notably, 8.1% of pupils had abnormal tympanometry despite normal audiometric screening results. Using Cohen’s kappa coefficient, the teacher-administered screening form (κ = 0.013) showed no significant agreement with the audiometric results. Meanwhile, otoscopy (κ = 0.158) and tympanometry (κ = 0.382) demonstrated significant agreement with the audiometric results.</p> Conclusions <p>Children of any socioeconomic status can suffer hearing impairment. A hearing screening form completed by trained primary school teachers failed to capture childhood hearing impairment in Thailand and should be revised to improve its sensitivity. Moreover, in future hearing screening programs, the use of both auditory and tympanometry should be considered to provide the most reliable outcomes.</p>