Details:

Creators:
Greeley, H.P. ; Roma, P.G. ; Mallis, M.M. ; Hursh, S.R. ; Mead, A.M. ; ... More +
Greeley, H.P. ; Roma, P.G. ; Mallis, M.M. ; Hursh, S.R. ; Mead, A.M. ; Nesthus, T.E. Less -
Corporate Creators:
Institutes for Behavior Resources ; Response Applications, LLC ; Civil Aerospace Medical Institute
Institutes for Behavior Resources ; Response Applications, LLC ; Civil Aerospace Medical Institute Less -
Subject/TRT Terms:
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Aviation Safety Behavior Fatigue (Physiological Condition) Field Studies Flight Crews Human Subject Testing Neurology Performance Tests Reaction Time Sleep Speech
Publication/ Report Number:
DOT/FAA/AM-13/19
Resource Type:
Tech Report
Geographical Coverage:
United States
Corporate Publisher:
United States. Office of Aerospace Medicine
Abstract:
Impaired neurobehavioral performance induced by fatigue may compromise safety in 24-hr operational

environmentssuch as aviation. As such, non-invasive, reliable, and valid methods of objectively detecting

compromised performance capacity in operational settings could be valuable as a means of identifying,

preventing, and mitigating fatigue-induced safety risks. One approach that has attracted attention in recent

years is quantitative speech analysis, but the extent of its operational feasibility, validity of the metrics, and

sensitivity to operationally-relevant factors in aviation remains unknown. To this end, the present report offers

an initial proof-of-concept evaluation of a speech analysis method based on Cepstrum Coefficient modeling,

using voice files from a broad sample of 195 cabin crew personnel collected during the 2009-2010 U.S. Civil

Aerospace Medical Institute-sponsored Flight Attendant Field Study (Roma et al., 2010).

Using a personal digital assistant device, participants recited five standardized phrases in random order

before and after each workday and sleep episode throughout their respective 3-4 week study periods.

Operational acceptability of the procedure was high, as indicated by high protocol compliance and, despite the

inherent variability of the timing and environments in which the test sessions occurred, the 13,975 files from

2,795 valid sessions were of sufficient quality for formal analysis. Individualized “baseline” speech models

were built from the files collected during test sessions coinciding with optimal neurobehavioral performance,

as determined by 5-min Psychomotor Vigilance Test (PVT) reaction times(RT), then speech deviation scores

relative to individual baseline models were calculated for the test sessions that preceded and concluded each

“trip” of multiple consecutive work days. Regarding validity, speech scores correlated significantly with PVT

RTs and Lapses(RTs > 500 msec), with a stronger relationship to Lapses, but high variability at the low range

of both performance variables suggests the influence of other factors. Regarding sensitivity to operational

factors, average Pre-Trip vs. Post-Trip speech scores differed significantly, although scores unexpectedly

decreased from Pre to Post, an artifact attributable to the composition of the baseline session pool.

Nonetheless, the pattern of speech data echoed performance data from our previous report in which scores

were most affected in crew of Regional carriers, with Junior seniority, and in Domestic operations.

These initial results reveal promising validity and sensitivity of Cepstrum Coefficient modeling for speech

signal analysis of fatigue in dynamic operational environments. Remaining questions underscore the need to

further explore the dataset to determine the precise relationship between speech production and

neurobehavioral performance capacity, the parameters for constructing individualized models, and

standardized quantitative speech-based definitions of fatigue.


Format:
PDF
Collection(s):
US Transportation Collection FAA Civil Aerospace Medical Institute
Main Document Checksum:
[+]
urn:sha256:c8c04c75ce291eb4d14deca2695312b65c87d601e579a90fd7ff1b2dd5d40aeb
Download URL:
https://rosap.ntl.bts.gov/view/dot/26637/dot_26637_DS1.pdf
File Type:

Supporting Files

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