Methods and evaluation of physiological measurements with acoustic stimuli-a systematic review.

 The detection of psychological loads, such as stress reactions, is receiving greater attention and social interest, as stress can have long-term effects on health O'Connor, Thayer and Vedhara (2021, 663-688). Acoustic stimuli, especially noise, are investigated as triggering factors. The application of physiological measurements in the detection of psychological loads enables the recording of a further quantitative dimension that goes beyond purely perceptive questionnaires. Thus, unconscious reactions to acoustic stimuli can also be captured. The numerous physiological signals and possible experimental designs with acoustic stimuli may quickly lead to a challenging implementation of the study and an increased difficulty in reproduction or comparison between studies. An unsuitable experimental design or processing of the physiological data may result in conclusions about psychological loads that are not valid anymore. The systematic review according to the preferred reporting items for systematic reviews and meta-analysis standard presented here is therefore intended to provide guidance and a basis for further studies in this field. For this purpose, studies were identified in which the participants' short-term physiological responses to acoustic stimuli were investigated in the context of a listening test in a laboratory study. A total of 37 studies met these criteria and data items were analysed in terms of the experimental design (studied psychological load, independent variables/acoustic stimuli, participants, playback, scenario/context, duration of test phases, questionnaires for perceptual comparison) and the physiological signals (measures, calculated features, systems, data processing methods, data analysis methods, results). The overviews show that stress is the most studied psychological load in response to acoustic stimuli. An ECG/PPG system and the measurement of skin conductance were most frequently used for the detection of psychological loads. A critical aspect is the numerous different methods of experimental design, which prevent comparability of the results. In the future, more standardized methods are needed to achieve more valid analyses of the effects of acoustic stimuli.