While preparing a lecture for the PhD students at the Norwegian Academy of Music, I came across some of the sound files I created for my MA thesis on salience in (musical) sound perception. While the content of that thesis is now mostly interesting as a historic document, I had a good time listening to the sound examples again. There are three things, in particular, that I still find interesting:
1. Duration of sound
How short sound excerpts are musically meaningful? Try, for example, these cuts from the opening of Eric Clapton’s “Tears in Heaven”:
When asking people (mainly student groups), my experience is that some people actually manage to recognise the tune after only listening to the first fragment (134 ms), and a lot of people manage to recognise it after the second fragment (380 ms). This I find quite remarkable, considering how little (sonic) information is actually there. It is a great example of the fantastic capabilities of our auditory system.
2. Number of sinusoidal components
Another thing I tested in the thesis, was how timbre influences our perception of sound. To test this I created a set of examples of how a different number of sinusoidal components of a saxophone tone (played by [Sony Rollins](http://en.wikipedia.org/wiki/Sonny_Rollins)) influence the perceived timbral quality:
It is first with 60 sinusoidal components present that we really get to hear all the timbral features of the sound properly, yet the tonal content (the pitch) is preserved with only a few sinusoidal components.
3. Sound thumbnailing
While the above example focused on reduction in (timbral) space, I also tested reduction of sound in the temporal space. There has been a lot of research on sound thumbnails since the time I did my experiments. I still find the idea of creating really short sonic summaries of longer musical examples fascinating. Here are my tests of creating different types of thumbnails of Ravel’s Bolero: