1996
The 1996 article
"Designing urgency into auditory warnings using pitch, speed and loudness" by E.C. Haas and J. Edworthy, published in the Computing and Control Engineering Journal, is a scientific study exploring how specific acoustic variables can be used to communicate different levels of emergency.
While this is a technical engineering paper, it is fundamentally linked to Max Neuhausthrough his extensive research and eventual 1991 patent for a revolutionary emergency siren