Week1.5(jnd & timbre)

Just Noticilble Difference

What is the smallest interval we can hear? This question is termed the Just Noticeable Difference (JND) in pitch perception. JND can be investigated in different domains of perception:

• Here is an explanation of the concept with application in visual domain.

• JND in the audio domain could be about pitch discrimination, but could also be about spatial ability.

• And an experiment about JND for tempo changes.

You can use this website to test your pitch discrimination (read the instructions). A more detailed experimental setup is available here (testing for more then one frequency; You will need to grab the data the site generates and graph it - any spreadsheet application will work or you can try this online tool.

Categorical Perception.

Here is a broad overview of categorical perception. The phenomena was first identified with respect to speech perception. And a detailed and extensive survey of work on categorical perception from Bruno Repp.

You can test your own perception of categorising vowel sounds to understand the concept (and also consider the design of such a tool for studying the effect).

Timbre

Here are some point for discussion from the chapter you read:

• Explain the following: “independent acoustic correlates have been determined for the continuous dimensions by correlating the position along the perceptual dimension with a unidimensional acoustic parameter extracted from the sounds”

• Why are synthetic sounds useful for confirming the perceptual dimensions (Caclin et al. 2005)?

• They mention 3 properties for an accurate model of timbre. Why are these properties important?

• Discuss the relationship between the ability of listeners to “reliably identify large differences in the mechanisms of tone production” source identification and auditory stream integration.

• What does timbral invariance refer to?

• How could you use timbre representation of orchestral instrument to inform orchestration choices (or analyse orchestration)

Two detailed discussions of timbre here and here with examples and illustrations.

In the next session we will talk about streaming and Gestalt. Please read:

• Chris Darwin on Auditory Grouping

• Roger Shepard on Stream Segregation

For additional background about Gestalt Principles read Shepard's chapter on the subject in Perry Cook's Music, Cognition, and Computerised Sound (chapter 3) and review of Gestalt (principally in visual domain) here.

Plans for Dec. 6th Music & Emotion debate:

Chapter 7 provides a good overview and you can download a more detailed discussion (also by Thompson) here.

As discussed in class we will be taking several perspective on this topic (with the named students taking the lead)

• 1. Deryck Cooke The Language of Music. More recent investigations of these ideas: here and here

  2. Kivy, P. (2006). Mood and Music: Some Reflections for Noël Carroll. Journal of Aesthetics and Art Criticism, 64(2), 271-281(available online through the library)

  3. Susanne Langer Philosophy in a New Key. A useful summary and discussion her work. Related ideas in E.T. Cone's Music: a View from Delft. Selected Essays

  4. Hevner, K. (1936). Experimental studies of the elements of expression in music. The American Journal of Psychology, 48(2), 246-268.

  5. Emotion and expectations Meyer Emotion and Meaning in Music to Huron Sweet Anticipation