Introduction and Rationale: Cholestasis is defined as reduced canalicular bile flow.Elevated serum concentration of direct bilirubin is a principal sign of cholestasis.Increased serum concentration of indirect bilirubin is present in most patients withcholestasis. Severe hyperbilirubinemia often results in hearing loss. However, theeffect of low serum levels of indirect bilirubin on hearing levels in infants andchildren with chronic cholestasis has not been previously studied.Aim of the work: To study the effect of level and duration of indirect hyperbilirubinemiaon the hearing level of infants and children with chronic cholestasis.Subjects and Methods: Thirty infants and children with chronic cholestasis weresubjected to full history taking, pediatric clinical examination, careful otologicalexamination and laboratory investigations (complete blood picture, serum total anddirect bilirubin and liver function tests) and audiological evaluation includingimmittancemetry, transient evoked otoacoustic emissions (TEOAEs) and auditorybrainstem response (ABR). Statistical analysis was conducted using the mean,standard error, standard deviation, student t-test and linear correlation coefficient bySPSS V17.Results: Duration of hyperbilirubinemia revealed a negative significant correlationwith TEOAEs reproducibility, TEOAEs response and TEOAEs amplitude at 1, 2 and4.5 kHz. ABR results revealed a negative significant correlation between duration ofhyperbilirubinemia and ABR wave latencies (III, V, I-III, III-V and I-V) and nonsignificantcorrelation with ABR threshold. As regards the indirect bilirubin level,there is statistically non-significant correlation with TEOAEs results. ABR resultsrevealed a positive significant correlation between indirect bilirubin level and ABRthreshold and ABR wave latencies (I, III).Conclusions: Effect of chronicity of hyperbilirubinemunia is evident on cochlearfunction as increase in duration of hyperbilirubinemia is associated with worsecochlear function (mainly the apex). Effect of hyperbilirubinemia is mainly on theearly ABR waves (I, III) (peripheral more than central). Level of hyperbilirubinemiarather than duration is the major risk factor on hearing level.Recommendations: Future studies for assessment of long term effect of chroniccholestasis on central test battery in infants and children with chronic cholestasis.Also, we recommend inclusion of TEOAEs amplitud and ABR in the audiologicalscreening of chronic cholestatic infants and children.