Emotional Responses to Auditory Hierarchical Structures is Shaped by Bodily Sensations and Listeners' Sensory Traits

Emotional responses to auditory stimuli are a common part of everyday life. However, for some individuals, these responses can be distressing enough to interfere with daily functioning. Despite their prevalence, the mechanisms underlying auditory-induced emotion remain only partially understood. Prior research has identified contributing factors such as auditory features, listener traits, and bodily sensations. However, most studies have focused on acoustic features, leaving the role of syntactic structure largely unexplored. This study specifically investigates how hierarchical syntactic structures influence emotional experience, in conjunction with listener traits and bodily sensations. An online experiment was conducted with 715 participants, who listened to 26 sound sequences varying systematically in hierarchical syntactic complexity. Sequences were generated by combining three types of local pitch movement with three types of global pitch movement in ascending and descending pitch directions, resulting in nine complexity levels. Participants rated the valence and arousal of each sequence and indicated any bodily sensations on a body map. Measures of sensory processing patterns were also collected. Results showed that emotional valence was associated with the complex interplay of moderate syntactic complexity ("not too simple, not too complex"), sensory sensitivity, and upper torso sensations. These findings expand existing research by identifying syntactic features that shape auditory-induced emotional experience and highlight the link between bodily sensation and emotional response. They also suggest potential applications for incorporating syntactic design into therapeutic approaches to emotion regulation.