A special thanks to David, Diana, Al Bregman and Dennis, Thank you so much for your suggestions and advice. I have also noticed that most of the studies done recently of relatively novel stimuli for auditory sequential stream segregation try using a stimulus discrimination task before the streaming task to correlate both.( Eg. If amplitude modulated noise is used then initially a modulation rate discrimination task is used and then streaming). I was wondering as to the importance of doing the discrimination task as I noticed that in most of the circumstances streaming only occured when the two stimuli were also perceptually discriminable ( i mean the streaming threshold was above the discrimination threshold).