An evaluation of three methods for unscrambling helium speech produced at depths of 800 and 1000 feet.
Joseph S. Russotti, Joseph R. Duffy · PsycEXTRA Dataset · 1969
Abstract : Three systems for 'unscrambling' helium speech produced at simulated depths of 800 and 1000 feet were evaluated. Recordings of the modified rhyme test read by an experienced male diver in a pressurized helium atmosphere were processed through three commercial frequency-shifting devices. The intelligibility of words passed through these systems was compared to scores obtained when the same helium recording was presented directly without alteration and when presented at one-half playback speed to groups of listeners. A within-subjects' design was employed with suitable counterbalancing so that no word was heard twice by the same listener.