Effects of high altitude on speech intelligibility

Abstract

A word articulation test score was used to study the relationship between altitude and intelligibility of earphone speech. Measurements were made on B-17F bombers descending and ascending from 5000 to 35000 feet. Results show that intelligibility falls off gradually to 25000 feet, then declines more rapidly. Experiments also were made with signal intensity and sentence length. Deterioriation in speech intelligibity is attributable to a depression in the operating efficiency of the voice, the microphone, and the earphones as the result of the reduced pressures encountered at high altitude. (PsycInfo Database Record (c) 2025 APA, all rights reserved)