Olsen Kirk N, Dean Roger T, Leung Yvonne
The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, New South Wales, Australia.
Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.
PLoS One. 2016 Dec 20;11(12):e0167643. doi: 10.1371/journal.pone.0167643. eCollection 2016.
Phrasing facilitates the organization of auditory information and is central to speech and music. Not surprisingly, aspects of changing intensity, rhythm, and pitch are key determinants of musical phrases and their boundaries in instrumental note-based music. Different kinds of speech (such as tone- vs. stress-languages) share these features in different proportions and form an instructive comparison. However, little is known about whether or how musical phrasing is perceived in sound-based music, where the basic musical unit from which a piece is created is commonly non-instrumental continuous sounds, rather than instrumental discontinuous notes. This issue forms the target of the present paper. Twenty participants (17 untrained in music) were presented with six stimuli derived from sound-based music, note-based music, and environmental sound. Their task was to indicate each occurrence of a perceived phrase and qualitatively describe key characteristics of the stimulus associated with each phrase response. It was hypothesized that sound-based music does elicit phrase perception, and that this is primarily associated with temporal changes in intensity and timbre, rather than rhythm and pitch. Results supported this hypothesis. Qualitative analysis of participant descriptions showed that for sound-based music, the majority of perceived phrases were associated with intensity or timbral change. For the note-based piano piece, rhythm was the main theme associated with perceived musical phrasing. We modeled the occurrence in time of perceived musical phrases with recurrent event 'hazard' analyses using time-series data representing acoustic predictors associated with intensity, spectral flatness, and rhythmic density. Acoustic intensity and timbre (represented here by spectral flatness) were strong predictors of perceived musical phrasing in sound-based music, and rhythm was only predictive for the piano piece. A further analysis including five additional spectral measures linked to timbre strengthened the models. Overall, results show that even when little of the pitch and rhythm information important for phrasing in note-based music is available, phrasing is still perceived, primarily in response to changes of intensity and timbre. Implications for electroacoustic music composition and music recommender systems are discussed.
乐句划分有助于听觉信息的组织，是言语和音乐的核心。毫不奇怪，强度、节奏和音高变化的各个方面是基于器乐音符的音乐中乐句及其边界的关键决定因素。不同类型的言语（如声调语言与重音语言）以不同比例共享这些特征，并形成了具有启发性的比较。然而，对于基于声音的音乐中乐句划分是如何被感知的，人们知之甚少。在基于声音的音乐中，创作一首曲子的基本音乐单元通常是连续的非器乐声音，而不是间断的器乐音符。这个问题构成了本文的研究目标。向20名参与者（其中17名未接受过音乐训练）呈现了六种源自基于声音的音乐、基于音符的音乐和环境声音的刺激。他们的任务是指出每次感知到的乐句出现，并定性描述与每个乐句反应相关的刺激的关键特征。研究假设是基于声音的音乐确实能引发乐句感知，并且这主要与强度和音色的时间变化有关，而不是节奏和音高。结果支持了这一假设。对参与者描述的定性分析表明，对于基于声音的音乐，大多数感知到的乐句与强度或音色变化有关。对于基于音符的钢琴曲，节奏是与感知到的音乐乐句划分相关的主要主题。我们使用代表与强度、谱平坦度和节奏密度相关的声学预测因子的时间序列数据，通过复发事件“风险”分析对感知到的音乐乐句的时间出现进行建模。声学强度和音色（这里由谱平坦度表示）是基于声音的音乐中感知到的音乐乐句划分的强预测因子，而节奏仅对钢琴曲具有预测性。包括与音色相关的另外五个频谱测量的进一步分析加强了模型。总体而言，结果表明，即使在基于音符的音乐中对乐句划分很重要的音高和节奏信息很少可用时，仍然能感知到乐句划分，主要是对强度和音色变化的反应。文中还讨论了对电子音乐作曲和音乐推荐系统的启示。
