Evaluating the Influence of Room Illumination on Camera-Based Physiological Measurements for the Assessment of Screen-Based Media

Camera-based solutions can be a convenient means of collecting physiological measurements indicative of psychological responses to stimuli. However, the low illumination playback conditions commonly associated with viewing screen-based media oppose the bright conditions recommended for accurately recording physiological data with a camera. A study was designed to determine the feasibility of obtaining physiological data, for psychological insight, in illumination conditions representative of real world viewing experiences. In this study, a novel method was applied for testing a first-of-its-kind system for measuring both heart rate and facial actions from video footage recorded with a single discretely-placed camera. Results suggest that conditions representative of a bright domestic setting should be maintained when using this technology, despite this being considered a sub-optimal playback condition. Further analyses highlight that even within this bright condition, both the camera-measured facial action and heart rate data contained characteristic errors. In future research, the influence of these performance issues on psychological insights may be mitigated by reducing the temporal resolution of the heart rate measurements and ignoring fast and low-intensity facial movements

The relationship between environmental context and attentional engagement in podcast listening experiences

Previous research has shown that podcasts are most frequently consumed using mobile listening devices across a wide variety of environmental, situational, and social contexts. To date, no studies have investigated how an individual’s environmental context might influence their attentional engagement in podcast listening experiences. Improving understanding of the contexts in which episodes of listening take place, and how they might affect listener engagement, could be highly valuable to researchers and producers working in the fields of object-based and personalised media. An online questionnaire on listening habits and behaviours was distributed to a sample of 264 podcast listeners. An exploratory factor analysis revealed five factors of environmental context that influence attentional engagement in podcast listening experiences. The factors were labelled as: outdoors, indoors & at home, evenings, soundscape & at work, and exercise. The soundscape & at work factor suggests that some listeners actively choose to consume podcasts to mask disturbing stimuli in their surrounding soundscape. Five aspects of podcast listening engagement were also defined and measured across the sample, providing a comprehensive quantitative account of contemporary podcast listening experiences. Further analysis suggested that the proposed factors of environmental context were positively correlated with the measured aspects of podcast listening engagement. The results presented support the hypothesis that elements of a listener’s environmental context can influence their attentional engagement in podcast listening experiences. They are highly pertinent to the fields of podcast studies, mobile listening experiences, and personalised media, and provide a basis for researchers seeking to explore how other forms of listening context might influence attentional engagement

Data to accompany "Automatic text clustering for audio attribute elicitation experiment responses"

Data to accompany "Automatic text clustering for audio attribute elicitation experiment responses". Includes text clustering code, experiment responses, and manually generated clusters. | Version:

Data to accompany "Determination and validation of mix parameters for modifying envelopment in object-based audio"

Data to accompany "Determination and validation of mix parameters for modifying envelopment in object-based audio". Includes audio files, experiment results, code for generating plots

Perceptual Evaluation of Audio-On-Audio Interference in a Personal Sound Zone System.

There are many situations in which two or more audio programmes may be replayed in the same acoustic space. Such situations can either occur naturally or be deliberately engendered, for example in a system designed to produce personal sound zones. In order to improve the experience of a listener in the presence of an audio interferer, it is desirable to model the relationship between listener experience and physical parameters of the situation. Such a model could be used to optimise audio-on-audio interference situations in a perceptually relevant manner. The first stage of this research involved determination of attributes of the perceptual experience of a listener in an audio-on-audio interference situation. Attributes used in similar research areas were reviewed and an elicitation experiment-combining aspects of individual and group direct elicitation methods preceding a rating experiment—was performed. ‘Distraction’ was found to be the most relevant attribute for describing the experience of a listener in an audio-on-audio interference situation. The next stage of the research consisted of determining relevant physical parameters and producing a model of distraction. An experiment was performed in which distraction ratings were collected for one hundred randomly created audio-on-audio interference stimuli. Physical parameters were determined following a verbal protocol analysis performed on written descriptions of reasons for the perceived distraction; the resultant categories were used to suggest appropriate features. A linear regression procedure was used to determine the relationship between the features and distraction scores. The selected features were: overall loudness; loudness-based target-to-interferer ratio (TIR); Perceptual Evaluation for Audio Source Separation (PEASS) toolbox interference-related perceptual score (IPS); level range in the high frequency bands of the interferer; and percentage of temporal windows with low TIR. The resultant model was found to fit well to the training and validation data sets with a root-mean-square error (RMSE) of approximately 10%

Perceptual Evaluation of Audio-On-Audio Interference in a Personal Sound Zone System.

There are many situations in which two or more audio programmes may be replayed in the same acoustic space. Such situations can either occur naturally or be deliberately engendered, for example in a system designed to produce personal sound zones. In order to improve the experience of a listener in the presence of an audio interferer, it is desirable to model the relationship between listener experience and physical parameters of the situation. Such a model could be used to optimise audio-on-audio interference situations in a perceptually relevant manner. The first stage of this research involved determination of attributes of the perceptual experience of a listener in an audio-on-audio interference situation. Attributes used in similar research areas were reviewed and an elicitation experiment-combining aspects of individual and group direct elicitation methods preceding a rating experiment—was performed. ‘Distraction’ was found to be the most relevant attribute for describing the experience of a listener in an audio-on-audio interference situation. The next stage of the research consisted of determining relevant physical parameters and producing a model of distraction. An experiment was performed in which distraction ratings were collected for one hundred randomly created audio-on-audio interference stimuli. Physical parameters were determined following a verbal protocol analysis performed on written descriptions of reasons for the perceived distraction; the resultant categories were used to suggest appropriate features. A linear regression procedure was used to determine the relationship between the features and distraction scores. The selected features were: overall loudness; loudness-based target-to-interferer ratio (TIR); Perceptual Evaluation for Audio Source Separation (PEASS) toolbox interference-related perceptual score (IPS); level range in the high frequency bands of the interferer; and percentage of temporal windows with low TIR. The resultant model was found to fit well to the training and validation data sets with a root-mean-square error (RMSE) of approximately 10%

IoSR Listening Room Multichannel BRIR Dataset

Dataset of binaural room impulse responses for a 22.2 reproduction system captured in the Institute of Sound Recording ITU BS.1116 listening room at the University of Surrey, Guildford, UK. SOFA format and Matlab versions

Determination and validation of mix parameters for modifying envelopment in object-based audio

Envelopment is an important attribute of listener preference for spatial audio reproduction. Object-based audio offers the possibility of altering the rendering of an audio scene in order to modify or maintain perceptual attributes - including envelopment - if the relationships between attributes and mix parameters are known. In a method of adjustment experiment, mixing engineers were asked to produce mixes of four program items at low, medium, and high levels of envelopment, in 2-channel, 5-channel, and 22-channel reproduction systems. The participants could vary a range of level, position, and equalization parameters that can be modified in object-based audio systems. The parameters could be varied separately for different semantic object categories. Nine parameters were found to have significant relationships with envelopment; parameters relating to the horizontal and vertical spread of sources were shown to be most important. A follow-on experiment demonstrated that these parameters can be adjusted to produce a range of envelopment levels in other program items