A modified hyperbaric speech transcoder

This paper deals with a technique for improving the restoration of the spectral properties of the speech of deep-sea divers operating under various conditions of gas mixtures and diving in depths. The technique used here is based on the modified digital channel vocoder. Intelligibility problems linked to hyperbasic speech are briefly described. A new version of frequency band is used with the usual channel vocoder. The hyperbasic speech records from "Hydra IV" (physiological experiments using pressurised helium diving) are processed to validate the proposed frequency distribution.