A survey on heliumspeech communications in saturation diving

With the development of society and the progress of technology, more and more ocean activities are carried out. It results in booming of deep-sea diving. The use of helium-oxygen mixture (as a kind of breathing gas) solves the physiological problems of divers in saturated diving, but it brings about the Heliumspeech voice communication problem, the drop of speech intelligibility. There is no doubt that the effective speech communication must be provided for supporting the life and work of divers in deep-sea. This paper describes the mechanism of forming heliumspeech, discusses the effects of pressure and helium environment on the speech spectrum, compares the pros and cons of the time-domain and frequency-domain unscrambling techniques, shows the challenges in heliumspeech communications. Finally, it briefly introduces the deep learning, and points out that deep learning/machine learning may be a perfectly unscrambling technique.