Date of Award

Fall 1999

Document Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Human Factors and Systems

Committee Chair

John A. Wise, Ph. D.

Committee Member

Albert Helfrick, Ph.D

Committee Member

Eric Vaden


The transition of air/ground communications, from its present analog structure to a new digital communications architecture, will span a 10-year time frame. Testing to date indicates that the potential for interference from the digital system to the analog system would be critical, especially for General Aviation (GA) aircraft. This type of interference can be described as short, random bursts of noise capable of completely obliterating parts of the voice communication. The subsequent degrading effects on voice radio communications could jeopardize flight safety. The masking of parts of important information would result in distracted attention, debilitated cognitive performance, high level of annoyance, and stress. The goal of the proposed experiment was to examine the degree to which such noise impacts voice radio communications intelligibility. A classic, well established psycho-acoustic method of measuring intelligibility was used. It was anticipated that the digital data radio communication interference would influence voice communication intelligibility and the ratio between the length of the burst and the length of the affected consonant would be critical for voice communication intelligibility. Based upon the results of the statistical analysis that was exactly what happened. Those words treated with higher LR were more difficult to identify that those treated with lower LR or with no interference at all.