“…Depending on the amount and diversity of sensors used during the data collection phase, several signals have been assessed and evaluated in various settings for the development of pain assessment systems. Some of the most prominently used signals constitute of the audio signal (e.g., paralinguistic vocalizations) (Tsai et al, 2016 , 2017 ; Thiam et al, 2017 ; Thiam and Schwenker, 2019 ), the video signal (e.g., facial expressions) (Rodriguez et al, 2017 ; Werner et al, 2017 ; Tavakolian and Hadid, 2019 ; Thiam et al, 2020b ), specific bio-physiological signals such as the Electrodermal Activity (EDA), the Electrocardiogram (ECG), the Electromyography (EMG), or the Respiration (RSP) signal (Walter et al, 2014 ; Campbell et al, 2019 ; Thiam et al, 2019a ), and also bodily expression signals (Dickey et al, 2002 ; Olugbade et al, 2019 ; Uddin and Canavan, 2020 ).…”