Melodic fission

[11] Timbral difference may override registral similarity in the perception of segregated streams.

[12] Additionally, quick and contrasting attack times in groups of tones lead to fission.

[14] Logically, the louder the volume of a group of tones, the greater likelihood of melodic fission.

[15] Perception of separate streams builds as the melodic sequence is repeated over time, first rapidly, and then at a decreased rate.

[16] However, a few factors can impede this process and "reset" fission perception, including silence between presentation of the melody,[17] alteration of signal location (right or left ear) of the melody, and abrupt changes in volume.