HELIUM SPEECH INVESTIGATIONS.
Final technical rept. Mar 68-Nov 69,
SINGER-GENERAL PRECISION INC PLEASANTVILLE N Y KEARFOTT DIV
Pagination or Media Count:
The essential steps for correction of helium speech distortions are providing bandwidth to 10 KHz, providing adequate compensation for loss of vocal output in the 2-8 KHz range, and reducing spectral envelope frequencies e.g., the formant bands to normal values while preserving the glottal rate of the talker. A helium speech translator based on these principles has been developed and tested. Both taped stimuli and real-time operation during dives were used for evaluation purposes. Highly successful performance was demonstrated with divers at pressure depths as great as 1000 feet. Objective word intelligibility test results were 88 at 500 feet and 78 at 800 feet, as compared with previously reported intelligibility of 5 for uncorrected helium speech at a depth of 600 feet. Author
- Voice Communications