Accession Number:

AD0001014

Title:

INTELLIGIBILITY OF SPEECH HEARD AT HIGH ALTITUDE AND SEA LEVEL

Descriptive Note:

Corporate Author:

OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS

Personal Author(s):

Report Date:

1952-10-30

Pagination or Media Count:

18.0

Abstract:

Four groups, of 10 men each, took part in speech-intelligibility tests conducted during simulated altitude runs at 43,000 ft. About half of each group served as speaker-listeners at altitude, and the other half functioned as listeners at sea level. Each speaker said about 14 words from the multiple- choice intelligibility test, while the listeners crossed out 1 of 4 alternatives for each test word. Each man wore a helmet with 1 earphone, while the other ear was open to the noise environment of 110 db. simulated aircraft noise. The speakers received response scores that gradually increased through the 15 runs. There was no significant difference between listener scores at sea level and at altitude. Speaking at altitude tended to restore the Osub2-COsub2 balance in the blood.

Subject Categories:

  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE