Systematic evaluation of perceived spatial quality

The evaluation of perceived spatial quality calls for a method that is sensitive to changes in the constituent dimensions of that quality. In order to devise a method accounting for these changes, several processes have to be performed. This paper shows the development of scales by elicitation and structuring of verbal data, followed by validation of the resulting attribute scales

Spatial impression: measurement and perception of concert hall acoustics and reproduced sound

ABSTRACT The fields of concert hall acoustics and sound reproduction are traditionally studied separately, with little interaction between them. However, it is apparent that a great deal can be gained from combining the two disciplines, as long as the differences are considered. Firstly, the perceived spatial impression afforded by the two acoustical situations is reviewed, and the similarities and differences are highlighted. Secondly, the optimum method for applying concert hall measurements to sound reproduction is assessed. Finally, the potential success of applying the developments made in measurements of sound reproduction systems to concert hall acoustics is considered

Subjective audio quality trade-offs in consumer multichannel audio-visual delivery systems. Part I: Effects of high frequency limitation

ABSTRACT The subjective effects of controlled high frequency limitation of the audio bandwidth on assessment of audio quality were studied. The investigation was focused on the standard 5.1 multichannel audio set-up (Rec. ITU-R BS.775-1) and limited to the optimum listening position. The effect of video presence on audio quality assessment was also investigated. The results of the formal subjective test indicate that it is possible to limit the high frequency content of the centre or of the rear channels without significant deterioration of the audio quality for some of the investigated programme material types. Video presence has small effect on audio quality assessment

Describing Subjective Experiment Consistency by pp-Value P-P Plot

There are phenomena that cannot be measured without subjective testing. However, subjective testing is a complex issue with many influencing factors. These interplay to yield either precise or incorrect results. Researchers require a tool to classify results of subjective experiment as either consistent or inconsistent. This is necessary in order to decide whether to treat the gathered scores as quality ground truth data. Knowing if subjective scores can be trusted is key to drawing valid conclusions and building functional tools based on those scores (e.g., algorithms assessing the perceived quality of multimedia materials). We provide a tool to classify subjective experiment (and all its results) as either consistent or inconsistent. Additionally, the tool identifies stimuli having irregular score distribution. The approach is based on treating subjective scores as a random variable coming from the discrete Generalized Score Distribution (GSD). The GSD, in combination with a bootstrapped G-test of goodness-of-fit, allows to construct $p$-value P-P plot that visualizes experiment's consistency. The tool safeguards researchers from using inconsistent subjective data. In this way, it makes sure that conclusions they draw and tools they build are more precise and trustworthy. The proposed approach works in line with expectations drawn solely on experiment design descriptions of 21 real-life multimedia quality subjective experiments.Comment: 11 pages, 3 figures. Accepted to 28th ACM International Conference on Multimedia (MM '20). For associated data sets, source codes and documentation, see https://github.com/Qub3k/subjective-exp-consistency-chec

Clergy in Place in England : Bias to the Poor or Inverse Care Law?

Faith traditions frequently proclaim priority for the poor and socially marginalised, emphasising individual and collective responsibility towards those in poverty. Ordained ministers or clergy – possibly the main investment of religious organisations – play a key role in encouraging and fulfilling that commitment in their local settings. This paper considers the availability of clergy to provide pastoral care in areas of high socio-economic deprivation. Data from the 2011 census of England are used to correlate area variations in the number of clergy with household and neighbourhood deprivation. Findings show that clergy are distributed inversely to socio-economic deprivation at the ecological level. Fewer clergy are available or readily accessible in the most deprived areas, raising questions about their ability to respond pastorally and act politically on behalf of the poor. Market forces that draw clergy deployments towards less deprived areas warrant further investigation

Elicitation and Grading of Subjective Attributes of 2-channel Phantom Images

The subjective attributes of 2-channel phantom images of transient piano, continuous trumpet and male speech sources were elicited using pair-wise comparison between reference mono images and their phantom images. The attributes elicited included ‘image focus’, ‘image width’, ‘image distance’, ‘brightness’, ‘hardness’ and ‘fullness’. The effect of interchannel time and intensity differences on the perceived difference between the real image and its phantom image was investigated for each sound source in respect of the elicited subjective attributes. Results show that the type of panning method (pure time, pure intensity and combination of the two) had a statistically significant effect on image focus and image width attributes. It was also found that the type of sound source had a significant effect on all the attributes

Investigation into the Effect of Interchannel Crosstalk in Multichannel Microphone Technique

A series of subjective listening tests were carried out in order to investigate the effect of interchannel crosstalk in multichannel microphone technique. Perceived attributes of interchannel crosstalk images were first elicited, and then graded with various independent variables, including different types of microphone array (different combinations of time and intensity differences), sound source and acoustic condition. The results showed that the most dominant effects of interchannel crosstalk were an increase of source width and a decrease of locatedness. The ratio of time and intensity differences in microphone array was the most significant factor for both effects. Sound source type had a significant effect for source width increase, but not for the locatedness decrease. Acoustic condition was significant for locatedness decrease, but not for source width increase. This paper describes the experiment method, and presents and discusses the details of the result data

Perceptually modelled effects of interchannel crosstalk in multichannel microphone technique

One of the most noticeable perceptual effects of interchannel crosstalk in multichannel microphone technique is an increase in perceived source width. The relationship between the perceived source-width-increasing effect and its physical causes was analysed using an IACC-based objective measurement model. A description of the measurement model is presented and the measured data obtained from stimuli created with crosstalk and those without crosstalk are analysed visually. In particular, frequency and envelope dependencies of the measured results and their relationship with the perceptual effect are discussed. The relationship between the delay time of the crosstalk signal and the effect of different frequency content on the perceived source width is also discussed in this paper