Noise and Cyclic Loading Effects on Performance and Operator Functional State

Abstract

Studies that seek to assess work performance in simulated stressful work environments often report no performance decrements as they have typically used over-simplified cognitive tasks that do not challenge the operator's compensatory response, and performance measures not sensitive enough to identify strain states. The present research used cyclic loading and ambient noise manipulations to stretch the adaptive limits of the operators and to determine how performance can show evidence of (potential) breakdown. Hysteresis measures allowed the identification of strain carry-over effects. No effects of noise on performance were found. Task load effects were found only in subsidiary ‘secondary’ tasks however, with primary task performance protected across conditions. High noise conditions were considered to be more demanding and attracted higher levels of compensatory effort and fatigue, which increased even when task load levels were decreased. The results are considered with respect to Hockey's (1997) Compensatory Control Model, and implications discussed.