acceptable noise levels in arabic-persian bilinguals

Background and aim: acceptable noise level (anl) test is a reliable measure of people’s abi-lity to tolerate background noise. central nervous system is one of the determinant factors in subject’s tolerance of noise. bilinguals’ different central activity pattern may yield different anl test results from monolinguals. this study aims to compare noise tolerance function in arabic-persian bilinguals with persian monolinguals via persian version of anl. methods: in the present study, the persian version of anl was administered on 115 cases with normal hearing (56 male, 59 female) aged 18–37 years in three groups of the persian mon-olingual, sequential arabic-persian bilinguals, and simultaneous arabic-persian bilinguals. results: the statistical analysis revealed sig-nificant difference in most comfortable level (p = 0.002) and background noise level (p = 0.011) among three groups, i.e. between persian monolinguals and sequential arabic-persian bilinguals and between persian monolinguals and simultaneous arabic-persian bilinguals. in other words, mean scores of bilingual were higher than monolingual scores. there was no significant difference among three groups with regard to anl scores (p = 0.114). conclusion: despite the difference between persian monolinguals and arabic-persian bilinguals in most comfortable level and background noise level, there is no significance difference in anl results. therefore, auditory central proce-ssing acts similarly in normal hearing monolin-gual and bilingual subjects. as a result, persian version of anl can be used for arabic-persian bilinguals, too.