Freya Bailes

Synchronization can influence trust following virtual interaction

Synchronization has recently received attention as a form of interpersonal interaction that may affect the affiliative relationships of those engaged in it. While there is evidence to suggest that synchronized movements lead to increased affiliative behavior (Hove & Risen, 2009; Valdesolo & DeSteno, 2011; Wiltermuth & Heath, 2009), the influence of other interpersonal cues has yet to be fully controlled. The current study controls for these features by using computer algorithms to replace human partners. By removing genuine interpersonal interaction, it also tests whether sounds alone can influence affiliative relationships, when it appears that another human agent has triggered those sounds. Results suggest that subjective experience of synchrony had a positive effect on a measure of trust, but task success was a similarly good predictor. An objective measure of synchrony was only related to trust in conditions where participants were instructed to move at the same time as stimuli.

Time series analysis as a method to examine acoustical influences on real-time perception of music

Multivariate analyses of dynamic correlations between continuous acoustic properties (intensity and spectral flatness) and real-time listener perceptions of change and expressed affect (arousal and valence) in music are developed, by an extensive application of autoregressive Time Series Analysis (TSA). TSA offers a large suite of techniques for modeling autocorrelated time series, such as constitute both musics acoustic properties and its perceptual impacts. A logical analysis sequence from autoregressive integrated moving average regression with exogenous variables (ARIMAX), to vector autoregression (VAR) is established. Information criteria discriminate amongst models, and Granger Causality indicates whether a correlation might be a causal one. A 3 min electroacoustic extract from Wisharts Red Bird is studied. It contains digitally generated and transformed sounds, and animate sounds, and our approach also permits an analysis of their impulse action on the temporal evolution and the variance in the perceptual time series. Intensity influences perceptions of change and expressed arousal substantially. Spectral flatness influences valence, while animate sounds influence the valence response and its variance. This TSA approach is applicable to a wide range of questions concerning acoustic- perceptual relationships in music.

Acoustic intensity causes perceived changes in arousal levels in music : an experimental investigation

Listener perceptions of changes in the arousal expressed by classical music have been found to correlate with changes in sound intensity/loudness over time. This study manipulated the intensity profiles of different pieces of music in order to test the causal nature of this relationship. Listeners (N = 38) continuously rated their perceptions of the arousal expressed by each piece. An extract from Dvoraks Slavonic Dance Opus 46 No 1 was used to create a variant in which the direction of change in intensity was inverted, while other features were retained. Even though it was only intensity that was inverted, perceived arousal was also inverted. The original intensity profile was also superimposed on three new pieces of music. The time variation in the perceived arousal of all pieces was similar to their intensity profile. Time series analyses revealed that intensity variation was a major influence on the arousal perception in all pieces, in spite of their stylistic diversity.

A rise–fall temporal asymmetry of intensity in composed and improvised electroacoustic music

A computational analysis of temporal patterns of acoustic intensity is applied to a series of recorded electroacoustic works in order to discern whether there are recurrent patterns in the intensity rise–fall structure. The works range from 1962 (Xenakis) to 2001 (Normandeau), and include composition and improvisation, large-scale (>25 minutes) and small-scale (<2 minutes) pieces, and acoustic, electronic and manipulated and synthesised sound. Contrary to Huron’s 1991 finding of long and gradual crescendi compared to short and abrupt decrescendi in classical music notation, it is found that in successive rise–fall events the rise phase (crescendo) is commonly shorter than the fall, and has a greater absolute rate of change of intensity than the fall. Correspondingly, crescendi occupy a smaller portion of the piece than decrescendi. When categorised into dynamic steps (such as p, mp, mf etc.), crescendi are usually less numerous than decrescendi. The results are considered from a cognitive point of view, in that this structuring may influence and thus result from listener attention and arousal patterns; and from a creator/performer point of view, in that embodied or virtualised effort may be key to the impact of an electroacoustic piece.

Musical Expertise and the Ability to Imagine Loudness

Most perceived parameters of sound (e.g. pitch, duration, timbre) can also be imagined in the absence of sound. These parameters are imagined more veridically by expert musicians than non-experts. Evidence for whether loudness is imagined, however, is conflicting. In music, the question of whether loudness is imagined is particularly relevant due to its role as a principal parameter of performance expression. This study addressed the hypothesis that the veridicality of imagined loudness improves with increasing musical expertise. Experts, novices and non-musicians imagined short passages of well-known classical music under two counterbalanced conditions: 1) while adjusting a slider to indicate imagined loudness of the music and 2) while tapping out the rhythm to indicate imagined timing. Subtests assessed music listening abilities and working memory span to determine whether these factors, also hypothesised to improve with increasing musical expertise, could account for imagery task performance. Similarity between each participant’s imagined and listening loudness profiles and reference recording intensity profiles was assessed using time series analysis and dynamic time warping. The results suggest a widespread ability to imagine the loudness of familiar music. The veridicality of imagined loudness tended to be greatest for the expert musicians, supporting the predicted relationship between musical expertise and musical imagery ability.

Listeners Discern Affective Variation in Computer-Generated Musical Sounds

We carried out two experiments to test the relationship between real-time perception of structural change in stylistically unusual musical sounds, and perception of its affect (arousal and valence). Computer music was used because of its unfamiliarity and our capacity to control it in ecologically appropriate ways. In experiment 1, thirteen participants unselected for musical training participated in tasks to detect segmentation and changes in affect. Changes in affect occurred upon detection of segmentation; but not all algorithmically distinct segments conveyed distinct affect. Short segments followed by long segments led to greater changes in arousal and valence at the point of segmentation than vice versa. In experiment 2, intra-segment sound transitions were introduced. Sixteen musicians performed the same affect task as in experiment 1, and a novel change in sound task. Participants were slow to respond to a continuous transition, but quick to respond to instantaneous transitions. Contrary to literature on the perception of affect in more familiar music, the musician participants in experiment 2 differed more in their ratings of arousal than of valence, in spite of a strong correlation of arousal with the composition of the stimuli. These findings are discussed in relation to the positive valence attributed to the more familiar sounds in both experiments.

Listening to the Mind Listening: An Analysis of Sonification Reviews, Designs and Correspondences

ABSTRACT Listening to the Mind Listening (LML) explored whether sonifications can be more than just noise in terms of perceived information and musical experience. The project generated an unprecedented body of 27 multichannel sonifications of the same dataset by 38 composers. The design of each sonification was explicitly documented, and there are 88 analytical reviews of the works. The public concert presenting 10 of these sonifications at the Sydney Opera House Studio drew a capacity audience. This paper presents an analysis of the reviews, the designs and the correspondences between timelines of these works.

Timbre as an Elusive Component of Imagery for Music

Evidence of the ability to imagine timbre is either anecdotal, or applies to isolated instrument tones rather than timbre in real music. Experiments were conducted to infer the vividness of timbre in imagery for music. Music students were asked to judge whether the timbre of a sounded target note was the same or different from the original following a heard, imagined, or control musical context. A pilot experiment manipulated instrumentation, while the main experiment manipulated sound filters. The hypothesis that participants are able to internalise timbral aspects of music was supported by an ability to perform the timbre discrimination task, and by facilitated response when imaging the timbre context compared with non-imaging. However, while participants were able to mentally represent timbre, this was not always reported as being a conscious dimension of their musical image. This finding is discussed in relation to previous research suggesting that timbre may be a sound characteristic that is optionally present in imagery for music.

The pulse of symmetry : on the possible co-evolution of rhythm in music and dance

Darwin proposed that music and dance may be part of courtship display leading to reproduction, and hence preservation of genes. Sexual selection could act on either or both music and dance, but we argue it may act most powerfully on their synergistic rhythmic co-performance. We suggest that motoric and temporal capacities evolved for, and adapted to, essential biological functions were exapted to working drills and to dance, and in combination with auditory capacities, to music. We propose that the recently observed correlation between bodily symmetry and perceived dancing quality in Jamaican dance is in part a reflection of the rhythmic abilities of the dancers: their capacity to produce and to synchronise with an isochronic pulse, and their simultaneous capacity to elaborate polyrhythms of movement in relation to that pulse. We elaborate empirical tests of these ideas. Since an exaptation can become a secondary adaptation, music/dance may have become an adaptation that favours reproductive success through sexual selection via display, as has been argued to apply to the studied Jamaican dancers and their community. The combination of dance with music may amplify such phenotypic success.

Generative Structures in Improvisation: Computational Segmentation of Keyboard Performances

Abstract We assessed the hypothesis elaborated by Pressing and by the first author that improvisation is normally based on the generation of segmental contrasts in musical features. Nine experienced improvisers performed a series of free- and 3-section referent-based pieces, each of about three minutes. Each player undertook eight improvisations with ‘referent’ instructions, preceded and followed by a free improvisation. A MIDI-equipped grand piano was used, and audio and MIDI were recorded. Computational analyses of the MIDI data assessed whether performers realized the referents successfully, and then determined the large-scale segmentation of the free improvisations. The performers almost always fulfilled the referents (68/72 improvisations, p < 0.0001), and their free improvisations were also susceptible to large-scale segmentation (p < 0.005). Since performers were only told of the referent structures as the session proceeded, the similar segmentation of both the first and second free improvisation suggests that such segmentation is common in solo free improvisation, in accord with the hypothesis.