Substitute sounds for ventriloquism and speech disorders

The restriction of articulation used by ventriloquists or caused by speech disorders can be compensated using substitute sounds. For a better understanding of these sounds, in this contribution the results of investigations of the substitute sounds by analysis and synthesis are presented. For that purpose the substitute sounds and their natural counterparts uttered by a ventriloquist are analyzed. Substitute sounds are also generated by articulatory synthesis and by a plaster model and are then compared to the original sounds. The results show that the perception of substitute sounds can reach the natural uttered sounds. The degree of the perceptive similarity depends on the substitute sound. The spectrum of the substitute sounds can replicate partially the spectrum of the natural sounds. However, for successful perception of the sound it is only necessary to reproduce the relevant spectral information. The knowledge about those sounds is interesting for speech therapy.