Speaker
Christoph Reuter
(Universität Wien)
Description
- Background: Joint cracking is caused by tribonucleation, the formation and implosion of gas bubbles in synovial fluid. Many individuals find the associated sound pleasant and report a stress-reducing effect. | - Research Questions: Which joints produce the most pleasant sensations and sounds? And which audio features account for this impression? | - Method: The cracking sounds of 224 finger joints, 54 cervical vertebrae, and 316 other joints of 40 participants (20 female, 18 male, 2 diverse, age 18-45; mean 23.2 years) were recorded with an Austrian Audio OC818 microphone in rooms with comparable acoustics (RT60<200ms) at the University of Vienna and TU Graz. Participants rated each of their cracking sounds in terms of associated physical feeling (e.g. “relaxing to tightening”) and sound impression (six items on property scales). The cracking sounds were then analyzed for over 150 audio features alongside the subjective evaluations and personality traits assessed via the Short Eysenck Personality Profiler (SEPPO). | - Results: Finger and cervical spine joints were the most frequently cracked and preferred, in particular cracking distal joints were perceived as the most satisfactory. Different joint types are distinguishable within a three-dimensional timbre space defined by Brightness, Attack Time, and Acoustic Annoyance (see interactive graph: https://muwiserver.univie.ac.at/body_crackles/brightness_annoyance_attacktime.htm). Finger cracking sounds were found to be brighter and less annoying than spinal cracks. Perceived pain correlated with increased timbral roughness and 500 Hz energy, whereas "liberating" sensations were linked to lower acoustic annoyance. Personality traits also influenced perception: extraverts perceived sounds as "fuller," while higher neuroticism correlated with higher perceived loudness.
Authors
Christoph Reuter
(Universität Wien)
Sarah Ambros
(Universität Wien)
Gabriel Feller
(Universität Wien)
Isabella Czedik-Eysenberg
(Universität Wien)
Christian Adams
(Graz University of Technology)
Jacqueline Wolf
(Graz University of Technology)
Michiel Postema
(Tampere University)