1The author would like to acknowledge the intellectual contribution of Steven Greenberg whose input, received during many discussions, has been instrumental in the development of the experiments reported. This research has been supported by NIH and the Veterans Affairs Medical Research.

2Throughout the paper, we will refer to auditory scene analysis based on primitive segregation (see , thought to occur automatically as a pre-attentive phenomenon, and ignore schema-driven segregation, which is assumed to relie on selective attention.

3As in “promise: an incomplete vow”.

4[Of course, a perfect overlap is not possible in the scheme adopted].

5The threshold difference may be regarded as the differential dx. One could disregard the threshold requirement in the above definition by assuming that any

x= x2-x1= x dx.