A study on the algorithm of helium speech enhancement

When divers work at deep sea, for physiological reasons, they must breathe helium-oxygen mixed atmosphere in place of air. Unfortunately, the resulting helium speech is distorted very much, and nearly unintelligible. This paper describes the essential law of helium speech transformation, presents two enhancement algorithms based respectively on short-term fourier transform and linear prediction. Our experimental results show that both algorithms can correct helium speech and the intelligibility is enhanced greatly.