BACKGROUND The dichotic hearing test consists of simultaneous stimulation of right and left ears with different messages, allowing analysis of the better or worse selective integration of these messages. METHODS With the latest techniques, the tonal dichotic test is applied by listening to a sample of 90 persons, ages from between 20 and 50 years without antecedents of otologic, neurologic nor psiquiatric disorders, valuing their discriminative and dominant capacity for lateral hearing. RESULTS The test is chosen effectively arranging the persons by their stereophonic capacity, like something adding but is as not as their simple biaural hearing capacity is, it is found an average capacity of hearing of the 79.856% in the left ear while there is only in 74.856% of in the right ear, which represents a dominance or increased value for the left ear. CONCLUSIONS Separating within the general sample the right-handed (60 persons) from the left-handed (30 persons), there is not found any meaningful differences neither concerning capacity of discrimination nor of dominance. Separating them by sexes (58 women and 32 men) no meaningful differences are found either in discriminative capacity or in dominance.