AbstractBackground: A bright circumstance, cold temperatures with loud noise and many activities around can influence oxygen saturation and pulse in preterm baby. Purpose: This study aimed to identify the effect of using earmuffs and earplugs on the physiological response of preterm infants. Methods: This crossover study involved 15 medically stable preterm infants treated in a closed incubator. It used the consecutive sampling technique where the babies’ physiological response using Neonatal Pulse Oximetri was observed for 30 seconds every 15 minutes for two hours of using earmuffs and earplugs.Results: The result of repeated ANOVA analysis showed that there is no significant difference of pulse repetition frequency before, during, and after using the earmuff and earplug to preterm infants. Meanwhile, statistically, there was a difference in the mean of oxygen saturation during and after using the earmuff with p = 0.019.Conclusion: The use of ear protection (earmuff and earplug) could assist and support premature infants in maintaining physiological condition. Earplugs are considered better than earmuffs for maintaining a preterm infant’s physiological condition.