Finding the words for it: how alexithymia can account for apparent deficits in the ability of an ASD group to describe their emotional responses to music

The basis for a talk delivered at the 11th International Conference on Music Perception and Cognition (ICMPC11), 23-27 August 2010, Seattle, Washington

Investigating computational models of perceptual attack time

The perceptual attack time (PAT) is the compensation for differing attack components of sounds, in the case of seeking a perceptually isochronous presentation of sounds. It has applications in scheduling and is related to, but not necessarily the same as, the moment of perceptual onset. This paper describes a computational investigation of PAT over a set of 25 synthesised stimuli, and a larger database of 100 sounds equally divided into synthesised and ecological. Ground truth PATs for modeling were obtained by the alternating presentation paradigm, where subjects adjusted the relative start time of a reference click and the sound to be judged. Whilst fitting experimental data from the 25 sound set was plausible, difficulties with existing models were found in the case of the larger test set. A pragmatic solution was obtained using a neural net architecture. In general, learnt schema of sound classification may be implicated in resolving the multiple detection cues evoked by complex sounds

Towards a style-specific basis for computational beat tracking

Outlined in this paper are a number of sources of evidence, from psychological, ethnomusicological and engineering grounds, to suggest that current approaches to computational beat tracking are incomplete. It is contended that the degree to which cultural knowledge, that is, the specifics of style and associated learnt representational schema, underlie the human faculty of beat tracking has been severely underestimated. Difficulties in building general beat tracking solutions, which can provide both period and phase locking across a large corpus of styles, are highlighted. It is probable that no universal beat tracking model exists which does not utilise a switching model to recognise style and context prior to application

Cross-cultural representations of musical shape

In cross-cultural research involving performers from distinct cultural backgrounds (U.K., Japan, Papua New Guinea), we examined 75 musicians' associations between musical sound and shape, and saw pronounced differences between groups. Participants heard short stimuli varying in pitch contour and were asked to represent these visually on paper, with the instruction that if another community member saw the marks they should be able to connect them with the sounds. Participants from the U.K. group produced consistent symbolic representations, which involved depicting the passage of time from left-to-right. Japanese participants unfamiliar with English language and western standard notation provided responses comparable to the U.K. group's. The majority opted to use a horizontal timeline, whilst a minority of traditional Japanese musicians produced unique responses with time represented vertically. The last group, a non-literate Papua New Guinean tribe known as BenaBena, produced a majority of iconic responses which did not follow the time versus pitch contour model, but highlighted musical qualities other than the parameters intentionally varied in the investigation, focusing on hue and loudness. The participants' responses point to profoundly different 'norms' of musical shape association, which may be linked to literacy and to the functional role of music in a community

Tonal music theory: A psychoacoustic explanation?

From the seventeenth century to the present day, tonal harmonic music has had a number of invariant properties such as the use of specific chord progressions (cadences) to induce a sense of closure, the asymmetrical privileging of certain progressions, and the privileging of the major and minor scales. The most widely accepted explanation has been that this is due to a process of enculturation: frequently occurring musical patterns are learned by listeners, some of whom become composers and replicate the same patterns, which go on to influence the next “generation” of composers, and so on. In this paper, however, I present a possible psychoacoustic explanation for some important regularities of tonal-harmonic music. The core of the model is two different measures of pitch-based distance between chords. The first is voice-leading distance; the second is spectral pitch distance—a measure of the distance between the partials in one chord compared to those in another chord. I propose that when a pair of triads has a higher spectral distance than another pair of triads that is voice-leading-close, the former pair is heard as an alteration of the latter pair, and seeks resolution. I explore the extent to which this model can predict the familiar tonal cadences described in music theory (including those containing tritone substitutions), and the asymmetries that are so characteristic of tonal harmony. I also show how it may be able to shed light upon the privileged status of the major and minor scales (over the modes)