ObjectivesTo examine the associations of sleep duration (SPD) and noise exposure with hearing loss (HL) among Chinese and American adults.DesignTwo cross-sectional studies.SettingThe National Health and Nutrition Examination Survey (2011–2012), and Zhejiang Chinese participants between 1 January 2018 and 1 November 2021.Participants3322 adults from the USA and 4452 adults from Zhejiang, China.Main outcome measuresHL was defined as a pure-tone average >20 dB in the better ear at low frequency (500, 1000 and 2000 Hz), speech frequency (500, 1000, 2000 and 4000 Hz) or high frequency (3000, 4000, 6000 and 8000 Hz). Binary logistic regression analysis quantified the associations between SPD, noise exposure (at work or off-work) and HL.ResultsSPD ≥8 hours/night had an OR of 0.71 (95% CI 0.59 to 0.84) for high-frequency HL vs. an SPD of 6–8 hours/night among the Chinese participants but had an OR of 1.28 (95% CI 1.03 to 1.58) among American participants. Noise exposure (both at work and off-work) was associated with poorer low-frequency (OR 1.58, 1.43; p<0.05), speech-frequency (OR 1.63, 1.29; p<0.05) and high-frequency (OR 1.37, 1.23; p<0.05) hearing among the Chinese participants; and it was associated with worse high-frequency hearing (OR 1.43, 1.66; p<0.05) among the American participants. The negative relationship between SPD ≥8 hours/night and HL was mainly observed in the Chinese participants with noise exposure (OR <1, p<0.05), and SPD ≥8 hours/night associated with poorer HF hearing was only identified in the American participants without noise exposure (OR >1, p<0.05).ConclusionsNoise exposure was associated with poorer hearing. SPD ≥8 hours/night was negatively associated with HL in the Chinese participants especially when exposed to noise. SPD ≥8 hours/night was related to poorer high-frequency hearing in the American participants when they had no noise exposure.