Auditory Displays: If They are so Useful,Why are they Turned Off?

Abstract

Pilots often turn off the auditory displays which are provided to improve their performance (Weiner, 1977; Veitengruber, Boucek, & Smith, 1977). The intensity of the auditory display is often cited as a possible cause of this behavior (Cooper, 1977). However, the processing of the additional information is a concurrent task demand which may increase subjective workload (Wickens & Yeh, 1983; McCloy, Derrick, & Wickens, 1983). Pilots may attempt to reduce subjective workload at the expense of performance by turning off the auditory display.

Forty undergraduate males performed a visual search task. Three conditions: auditory display on, auditory display off, and subject's choice were run in combination with nine levels of visual display load. The auditory display, a 4000 Hz tone with a between-subject intensity of 60 dB(A), 70 dB(A), 80 dB(A), and 90 dB(A), indicated that the target letter was in the lower half of the search area. NASA-TLX (Task Load Index) was used to measure the subjective workload of the subjects after each block of trials (Hart & Staveland, 1988).

A non-monotonic relationship was found between auditory display intensity and auditory display usage. Evidence was found that the auditory display increased some aspects of subjective workload– physical demands and frustration. Furthermore, there was a dissociation of performance and subjective workload in the manner predicted by Wickens – Yeh (1983). The implications of these results for display design are discussed.

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References

Boucek

J. P.

Veitengruber

J. E.

Smith

W. D.

Osgood

A. G.

(1977). Aircraft Alerting System Criteria Study, Vol II: Human Factors Guidelines for Aircraft Alerting Systems. Report No. FAA-RD-76–222, II, May 1977.

Cooper

G. E.

(1977). A Survey of the Status and Philosophies Relating to Cockpit Warning Systems. Report No. NASA-CR-152071, June 1977.

Hart

S. G.

Staveland

L. E.

(1988). The development of NASA-TLX (Task Load Index): Results of Empirical and Theoretical Research. In Hancock Meshkati (Eds.) Human Mental Workload. Amsterdam: North Holland Press.

Herron

(1980). A case for early objective evaluation of candidate display formats. Proceedings of the Human Factors Society-24th Annual Meeting, Los Angeles, CA, 1980.

McCloy

T. M.

Derrick

W. L.

Wickens

C. D.

(1983). Workload Assessment Metrics- What Happens When They Dissociate?, In Second Aerospace Behavioral Engineering Conference Proceedings, Warrendale, PA, Society of Automotive Engineers, 1983.

Veitengruber

J. E.

Boucek

G. P.

Smith

W. D.

(1977). Aircraft Alerting System Criteria Study, Vol. I: Collection and Analysis of Aircraft Alerting System Data. Report No. FAA-RD-76–222, I, May 1977.

Wickens

C. D.

Yeh

Y. Y.

(1982). The dissociation of subjective ratings and performance. Proceedings, 1982 Annual Meeting of the IEEE Conference on Cybernetics and Society, Seattle WA, 1982.

Wickens

C. D.

Yeh

Y. Y.

(1983). The dissociation between subjective workload and performance: a multiple resource approach. Proceedings of the Human Factors Society-27th Annual Meeting, Norfolk, VA, 1983.

Wiener

E. L.

(1977). Controlled Flight into Terrain Accidents: System Induced Errors. Human Factors, 19(2), 171–181.