Homework 4 for MUSIC 220a

This is the homework submission for homework 4 by Thomas Walther.

The Auditory Streaming Illusion

The piece in this homework presents two examples for the streaming illusion. In the first part, four equally sounding instruments are placed in four different corners in space, playing staccato notes. As time progresses, these instruments move closer together and play more legato. The listener will feel that they form a single instrument.

In the second part, sixteen notes are slowly played after another, again by similar sounding instruments. This time, the difference in pitch is larger, and the notes are randomly positioned in space (by using binaural mixdown of 4 channel panning). While the first instrument plays staccato, the instruments two, three and four play more and more legato. The pace of the second part gradually increases, and the listener will hear how the legato instruments will start to blend in.
In the middle of this part, the instruments two, three and four blend into one instrument. Since the very short release time of the first instrument creates a 'click' sound, the first instrument does not group with the other. Indeed, the first instrument will actually sound like two separate instruments: one playing low, and one playing high notes.

At the end of the second part, a short break is introduced, where the attack and release times of the instruments are set to an equal value. This makes it sound like a single instrument. The illusion of this single instrument will not break as the music slows down again.

• hw4.ck
• resulting stereo audio file