Persistence of Echoic Memory Trace as a Function of Presentation Level

Abstract

Previous empirical research has demonstrated that even within clearly audible ranges (45-70 dB with less than 35 dB background noise), people tend to make more errors and take longer to respond to even simple auditory tasks as the presentation level of auditory stimuli decreases when attentional processing requirements are high (Baldwin, 1997, Baldwin, Struckman-Johnson, Galinsky, & Williams, 1999). The observed decrease in performance with decreasing decibel level may be due to shorter echoic memory traces, which could exacerbate demands on attentional resources during periods of high mental workload. In order to examine this hypothesis, participants were asked to listen to sets of tones and verbally indicate whether the second pattern in each set matched the first pattern while simultaneously performing a loading task involving simulated driving. Tonal sets varied according to the decibel level of presentation (60, 65, & 70 dB) and the delay period between presentation of the first tonal pattern and presentation of the second comparison pattern (2 s, 3 s, or 4 s). As predicted, a significant interaction between delay time and presentation level was observed with participants making more errors and requiring greater time to respond in the 4 s delay condition, particularly in the lower 60 dB presentation level condition. Population aging and associated increases in the incidence of hearing loss are occurring at a time when verbal displays are increasingly being used in complex environments. Additionally, the need for persons of diverse language backgrounds to communicate in occupational environments with less than optimum acoustical environments make design accommodations that facilitate cognitive processing of speech in complex systems imperative. Slight increases in presentation level may be one way to facilitate the communication process by increasing the duration during which verbal material may be accessed for processing.