Amplitude modulation structure in French and German poetry: universal acoustic physical structures underpin different poetic rhythm structures.

French and German poetry are classically considered to utilize fundamentally different linguistic structures to create rhythmic regularity. Their metrical rhythm structures are considered poetically to be very different. However, the biophysical and neurophysiological constraints upon the speakers of these poems are highly similar. Scientifically, this suggests that at the level of the acoustic physical structures that are produced orally, the two poetic genres may be rhythmically extremely similar. Here, we apply a language-blind computational model of linguistic rhythm based on features of the amplitude envelope (AE) to compute these physical stimulus characteristics. The model was applied to recordings of the recitation of metrical French and German poems by native speakers. Poems in free verse were not considered in the study. The results indicated that the acoustic physical structures of the poems were identical for the two languages in terms of temporal modulation patterns in the AE. This challenges the linguistic view that German poetry utilizes lexical stress to create prosodic alternation between strong and weak syllables, while French poetry relies on accentuation at the level of prosodic phrasing. Nevertheless, minor differences in physical structure could be detected by applying further modelling drawn, respectively, from the birdsong and neural connectivity literatures.