Relation between acoustic and articulatory dimensions of speech sounds
Eugen Klein · Elektronische Hochschulschriften der LMU München (Ludwig-Maximilians-Universität München) · 2020
In their daily communication, speakers produce speech by pushing a controlled air stream past their vocal folds and through a vocal tract configuration formed by a set of articulators which ultimately results in a certain acoustic output. In this sense, speech and, specifically, speech sounds can be understood as a relation between articulatory and acoustic dimensions. This idea is supported by more recent neuroimaging results which suggest that sensory representations of speech sounds are stored across auditory and somatosensory cortices and are characterized by neural auditory-somatosensory mappings. The overall aim of the current dissertation is to improve our understanding of the functional nature of this relation. To this end, this thesis investigates the influence of a stronger linguo-palatal contact on speakers’ ability to employ multiple concurrent compensatory strategies during production of vowels and fricatives. During the data analysis, speakers’ individual as well as average compensatory behavior is investigated by means of generalized additive mixed models (GAMM) and a supervised classification algorithm (random forest). A framework is then developed that allows to estimate the extent of spectral adaptations in vowels and fricatives and to draw a direct comparison between these sounds. The experimental results are discussed in the context of current speech production theories and agree with the overall idea that speech sounds are perceptuo-motor units comprising of articulatory movements which are shaped by perceptual properties and selected for their functional value for communication.