Towards an Acoustic-Semantic Space of Extreme Metal Vocal Styles

Extreme vocal techniques typical for metal, e.g. growling or screaming, are characterized by low harmonicity and high roughness and associated with expressive dimensions like "aggressiveness" [Tsai et al., 2010]. Based on audio features, classification into broad style categories is possible [Kalbag & Lerch, 2022]. Which audio features are associated with the perception of emerging expressive techniques/stylistic devices that go beyond previously known categories remains open. Short phrases were extracted from 105 metal vocal tracks, 10 pilot-rated by subjects for pairwise similarity (45 comparisons). The resulting similarity matrix serves as basis for a perceptual similarity space computed using multidimensional scaling (MDS). In another pilot experiment, free verbal associations are collected for all 105 excerpts. Preliminary analyses reveal a three-dimensional similarity space whose first major axis represents the contrast between harmonic vs. more inharmonic/rough singing (Harmonic-to-Noise Ratio: r=0.837, p=0.005; Spectral Complexity: r=-0.959, p