Music 171 homework 4
Psychoacousticians have long been interested in the phenomenon of streaming, in which a succession of sounds is heard as a single stream, like a melody or a person speaking. Cues that might contribute to hearing sounds as belonging to a stream might be proximity in time, pitch, amplitude, timbre, or physical location, This assignment is to reproduce a famous experiment (I believe due to David Wessel) in which a loop of six sounds is heard as a single stream if cycled slowly, but as two separate ones if cycled more quickly. The sounds in the loop are as follows:
PITCH TIMBRE
 65   flute
 69   oboe
 72   flute
 65   oboe
 69   flute
 72   oboe
The assignment uses two recordings: flute (pitch G4 or MIDI 67) and oboe (pitch A4 or MIDI 69); these are from freesound.org, by Carlos_Vaquero and acclivity respectively, and have a creative commons license (attribution; non-commercial): http://creativecommons.org/licenses/by-nc/3.0/.

At low speed (two notes per second) your successful patch should sound like this, and faster (10 per second) it should sound like this; notice that in the first case you hear an ascending three-note chord but in th esecond you hear two interlocked descending three-note chords.

To make the patch (each of the following steps is worth 2 points for a total of 10):

If you like you can load teh two samples into two arrays with "save contents" turned on. This will make for a rather large file (a couple of megabytes). Alternatively, you can use a "loadbang" object to load the two files by name but the names should then be exactly "flute-G4-mono.wav" and "oboe-A4-mono.wav" so that the TAs will have those files available in the same directory as your patch so that the loading works. In subsequent assignments you will have to turn in zip archives to supply file dependencies yourself.

back to music 171 main page