ROLE OF FAMILIARITY IN AUDITORY-DISCRIMINATION OF MUSICAL-INSTRUMENT - A LATERALITY STUDY

Normal subjects were presented with dichotic pairs of sounds differing in pitch-timbre combination. Their task was to detect a fixed target sound that occurred randomly but equally often in the right and the le ft ear in two-thirds of the trials. Half the subjects performed this t ask with sounds produced by familiar natural instruments (violin, flut e, guitar and drum), and the other subjects performed the same task bu t with the sounds played backwards, hence being less recognizable. Sub jects were quicker and more accurate in discriminating forwards than b ackwards played sounds, hence exhibiting sensitivity to familiarity wi th musical instrument sounds. Recourse to this knowledge was, however, not associated to a shift in laterality. For both familiar and unfami liar sounds, a robust left-ear advantage (LEA) was observed.