Towards a Perceptual Model of 'Punch' in Musical Signals

A perceptual model for the measurement of ‘punch’ in musical signals. Punch is an attribute that is often used to characterize music or sound sources that convey a sense of dynamic power or weight to the listener. A methodology is explored that combines signal separation and low level parameter measurement to produce a perceptually weighted ‘punch’ score. The parameters explored are the onset time and frequency components of the signal across octave bands. The ‘punch’ score is determined by a weighted sum of these parameters using coefficients derived through a large scale listening test. The model may have application in music information retrieval (MIR) and music production tools. The presentation presents findings outlined in the paper of the same title

Alternative Weighting Filters for Multi-Track Program Loudness Measurement

The ITU-Recommendation BS.1770 is now established throughout most of the broadcast industry. Program loudness measurement is undertaken through the summation of K-weighted energy and this summation typically involves material that is broadband in nature. We undertook listening tests to investigate the performance of the K-weighting filter in relation to perceived loudness of narrower band stimuli, namely octave-band pink noise and individual stems of a multitrack session. We propose two alternative filters based on the discrepancies found and evaluate their performance using different measurement window sizes. The new filters yield better performance accuracy for both pink noise stimuli and certain types of multitrack stem. Finally, we propose an informed set of parameters that may improve loudness prediction in auto mixing systems

Evaluation of a Perceptually-Based Model of "Punch" with Music Material

This paper evaluates a perceptually motivated objective model for the measurement of “punch” in musical signals. Punch is a perceptual attribute that is often used to characterize music that conveys a sense of dynamic power or weight. A methodology is employed that combines signal separation, onset detection, and low level parameter measurement to produce a perceptually weighted “punch” score. The model is evaluated against subjective scores derived through a forced pairwise comparison listening test using a wide variety of musical stimuli. The model output indicates a high degree of correlation with the subjective scores. Correlation results are also compared to other objective models such as Crest Factor, Inter-Band-Ratio (IBR), Peak-to-Loudness Ratio (PLR), and Loudness Dynamic Range (LDR)

Hybrid Multiresolution Analysis Of ‘Punch’ In Musical Signals

This paper presents a hybrid multi-resolution technique for the extraction and measurement of attributes contained within a musical signal. Decomposing music into simpler percussive, harmonic and noise components is useful when detailed extraction of signal attributes is required. The key parameter of interest in this paper is that of punch. A methodology is explored that decomposes the musical signal using a critically sampled constant-Q filterbank of quadrature mirror filters (QMF) before adaptive windowed short term Fourier transforms (STFT). The proposed hybrid method offers accuracy in both the time and frequency domains. Following the decomposition transform process, attributes are analyzed. It is shown that analysis of these components may yield parameters that would be of use in both mixing/mastering and also audio transcription and retrieval

Building the Foundations of Professional Expertise: creating a dialectic between work and formal learning

Recent critiques of management and teacher education curricula and teaching pay particular attention to the disconnection between the de-contextualised, formal knowledge and analytical techniques conveyed in university programmes and the messy, ill-structured nature of practice. At the same time, research into professional expertise suggests that its development requires bringing together different forms of knowledge and the integration of formal and nonformal learning with the development of cognitive flexibility. Such complex learning outcomes are unlikely to be achieved through a ‘knowledge transmission’ approach to curriculum design. In this article we argue that in many ways current higher education practices create barriers to developing ways of knowing which can underpin the formation of expertise. Using examples from two practice-focused distance learning courses, we explore the role of distance learning in enabling a dialogue between academic and workplace learning and the use of ‘practice dialogues’ among course participants to enable integration of learning experiences. Finally, we argue that we need to find ways in higher education of enabling students to engage in relevant communities of expertise, rather than drawing them principally into a community of academic discourse which is not well aligned with practice

Audio Dynamics - Towards a Perceptual Model of Punch

This thesis discusses research conducted towards the development of an objective model that predicts punch in musical signals. Punch is a term often used by engineers and producers when describing a particular perceptual sensation found in produced music. Music is often characterised by listeners as being punchier yet the term is subjective, in terms of its meaning and the subsequent auditory effect on the listener. An objective model of punch would therefore prove useful for both music classification purposes and as a possible further metric that could be employed in music production and mastering metering tools. The literature reviewed within this body of work encompasses both subjective and objective audio evaluation methods in addition to low-level signal extraction and measurement techniques. The review concludes that whilst there has been a great deal of work in the area of semantic description and audio quality measurement, low-level analysis with respect to the perception of punch remains largely unexplored. The project was completed in a number of phases each designed to investigate the perceptual effects resulting from manipulation of test stimuli. The rationale behind this testing was to establish the key low-level descriptors relating to the punch attribute with the aim of producing a final objective and perceptually based model. The listening tests in each phase were conducted according to the ITU-R BS 1534-1 recommendation. In producing an objective model for the prediction of punch, listener perception to the attribute shows a strong correlation to the signal onset times, octave frequency band, signal duration and dynamic range. The punch measure obtained using the model is named PM95, where 95 indicates the upper percentile used in the measurement. Secondary measures were also obtained as a result of the iterative approach adopted. These are Inter-Band-Ratio (IBR), Transient to Steady-state Ratio (TSR) and Transient to Steady-state Ratio+Residual (TSR+R). These measures are useful in quantifying overall audio quality with respect to its dynamic range across frequency bands in addition to being a more reliable metric for defining the overall compression being applied to a piece of music. In addition, the latter two measures proposed may be useful in highlighting perceptual masking artefacts. The completed perceptual punch model was validated using the scores obtained from a large scale and independently conducted forced pairwise comparison test using expert listeners and a wide range of musical stimuli. From the results obtained, the PM95 measure showed a ‘very strong’ positive correlation with listener punch perception. Both r and rho coefficients (0.849 and 0.833) being significant at the 0.01 level (2-tailed). The PM95M measure, which is the PM95 measure divided by the mean value of punch frames also correlated very well with the perceptual punch scale having both r and rho coefficients (0.707 and -0.750) being significant at the 0.05 level (2-tailed). A real-time implementation of the punch model (and other measures proposed in this thesis) could be utilised as extensions to the metrics currently being used in Music Information Retrieval