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The Facts About Male or Female Voices Being Better for Aircraft Warning Systems

The science of whether "Sexy Sally," "Nagging Nora" or "Barking Bob" is better is unclear.

Published July 2, 2024

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For years, debate has raged online as to whether male or female voices are best for aviation voice warning systems, so pilots can respond quickly and accurately (archived):

This post had gained 29,000 upvotes as of this writing, as well as 692 comments. But other posts argued the opposite was true (archived):

This post had received 1,100 upvotes and 144 comments, some speculating about the role of bias in our perception of gender in voice warning systems.

In the air, safety is paramount, and pilots must react to all manner of sensory stimuli to make the best decisions, so it is crucial that they hear spoken warnings. But the truth about which type of voice is best, as we'll see, is far more complicated, and science has yet to provide a full understanding of the issue. 

The History

In the 1950s, U.S. aircraft manufacturer Convair developed its B-58 Hustler, the first bomber airplane capable of breaking the sound barrier. The engineering on board was cutting edge for the time, and it included a voice warning system. Convair had determined that a female voice would be better able to get and keep the attention of young men, and hired actress Joan Elms to record the messages:


(Whitby Archives)

The pilots immediately nicknamed the voice "Sexy Sally." The recordings of Elms reading the warnings have been preserved.

As time went on, manufacturers began to use both female and male voices in U.S. planes and helicopters, which received the nickames "Bit***n' Betty" in the U.S. (Kim Crow, Erica Lane, Patricia Hoyt and Leslie Shook all lent her their voices) or "Nagging Nora" in the U.K. (Sue Milne was the voice in the European Eurofighter Typhoon) and "Barking Bob." The system would allow the pilots to choose the voice they preferred, male or female.

But the question researchers have tried to answer for decades has to do with these voices' ability to prompt fast and accurate responses from the people who operate the aircraft. And there, the problem is twofold: Pilots need a voice they can hear over the loud noises of a cockpit (acoustics); also, they need to actually listen to it, as opposed to tune it out. The latter brings up issues of bias. 

Acoustics or Sexism?

A warning system must stand out so pilots will hear it over chatter and communications between themselves, and between them and ground control. At a time when those fields were exclusively male, a female voice stood out better than a male voice, and this is the reason many computer voices, including voice warning systems, are female by default, according to CNN. But as society evolved and women began to join the ranks of air forces across the world, a voice's perceived gender ceased to be a factor of distinction. 

Several studies have tried to assess which voices best overcome a cockpit's ambient noise. In 1998, a paper from the Wright-Patterson Air Force Base looked at the ability of female pilots' voices to break through in typical cockpit conditions. They described a female voice as "high in frequency, lower in power" and more likely to be covered by "military noises." The study evaluated it in environmental noise going from 95 to 115 decibels and concluded that at 115 decibels and above, female voices were unintelligible. In such conditions, the authors of the paper recommended better noise-reduction equipment and calibration to support the communications of both male and female aviators.

Five years later, in 2003, a study at the University of Plymouth compared male and female voices in a noisy environment and assessed them for their acoustic and non-acoustic (i.e., social perceptions and biases regarding differences between men and women) properties and found the differences were "negligible," though they gave female voices a slight edge, as they were deemed better able to convey a "greater range of urgencies because of their usually higher pitch and pitch range." They added that the differences between the two types of voice didn't have anything to do with social factors, only with acoustics. "Semantics," the article argued, was also key.

This was contradicted in a 2009 study carried out by Defence Research and Development Canada. Here, the goal was to determine which type of voice and intonation in a voice warning system stood out from cockpit aviator chatter. In other words, it tried to determine what voice in a warning system could cause the pilots to respond in the best way.

Researcher Robert Arrabito tested different voice warnings systems, male and female, with varying degrees of urgency (whisper, monotone, and urgent). The participants in the study were both male and female. The first experiment tested the warning systems in a quiet environment, and there he found that the perceived sex of the voice warning system made no difference in terms of the participants' reaction times, though intonation did (i.e., monotone and urgent resulted in faster action). The second experiment, in noisy cockpit conditions, showed that for both male and female participants, a male voice speaking in either a monotone way or an urgent way prompted the best responses. This study suggested that perceived gender did not play a role in prompting a response, but acoustics did.

The science gets even more complicated because pilots have to distinguish between several voices and noises: that of their co-pilots, as the case may be; that of ground controllers; that of voice warning systems; and that of alerts and alarms. The Bureau of Transportation Statistics (BTS) said in a 2020 review of the literature on alarms, alerts and warnings that "alerts and alarms are dynamic and time sensitive, while warnings are static and usually permanent." According to the BTS, "sensory design" is key to guarantee that pilots can react quickly and accurately to emergency situations.

At the time of this writing, however, it appeared that sexism was much less of a factor than acoustics in ensuring that they can hear warnings and instructions correctly. But the question also seemed to require much more research to understand how aviators, male and female, perceive warning systems with male or female voices in real-life cockpit conditions. 

Sources

717voice. Cockpit Voice. 2008. YouTube, https://www.youtube.com/watch?v=r0AK4yxBGnM.

Arrabito, G. Robert. 'Effects of Talker Sex and Voice Style of Verbal Cockpit Warnings on Performance'. Human Factors, vol. 51, no. 1, Feb. 2009, pp. 3–20. PubMed, https://doi.org/10.1177/0018720808333411.

'"Bitchin' Betty," Voice of the F/A-18, Retires'. Popular Mechanics, 8 Mar. 2016, https://www.popularmechanics.com/military/weapons/news/a19834/the-voice-of-the-f-a-18-hornet-is-retiring/.

Bitching Betty. https://encyclopedia.pub/entry/28771. Accessed 28 June 2024.

Correspondent, Alex Ward Social Affairs. 'A Bad Case of Jetnag? Fighter Pilots to Get Cockpit Instructions from Female Voice "because It Relaxes Them More" (but They've Already Nicknamed Her Nagging Nora)'. Mail Online, 4 July 2012, https://www.dailymail.co.uk/news/article-2168713/Fighter-pilots-nagging-Nora-female-voice-commands-cockpit-Typhoon-jets.html.

Edworthy, J., et al. 'The Use of Male or Female Voices in Warnings Systems: A Question of Acoustics.' Noise & Health, Oct. 2003. Semantic Scholar, https://www.semanticscholar.org/paper/The-use-of-male-or-female-voices-in-warnings-a-of-Edworthy-Hellier/f64bff4f7c556ed131096426072a14b52480f7b4.

---. 'The Use of Male or Female Voices in Warnings Systems: A Question of Acoustics'. Noise & Health, vol. 6, no. 21, 2003, pp. 39–50.

Erica Lane Enterprises, Inc., a Woman-Owned, SBA Certified 8(a) HUBZone SDB. 3 June 2006, https://web.archive.org/web/20060603013300/http://www.eleinc.com/erica.shtml.

Griggs, Brandon. 'Why Computer Voices Are Mostly Female | CNN Business'. CNN, 21 Oct. 2011, https://www.cnn.com/2011/10/21/tech/innovation/female-computer-voices/index.html.

Kosur, James. '"Sexy Sally" And The History Of Female Voices Used In The Military's Aircraft Warning Systems | War History Online'. Warhistoryonline, 2 Aug. 2021, https://www.warhistoryonline.com/war-articles/sexy-sally-aircraft-voice-based-warning-systems-history.html.

Nixon, C. W., et al. 'Female Voice Communications in High Levels of Aircraft Cockpit Noises--Part I: Spectra, Levels, and Microphones'. Aviation, Space, and Environmental Medicine, vol. 69, no. 7, July 1998, pp. 675–83.

Ruskin, Keith J., et al. ATC Signaling Systems: A Review of the Literature on Alarms, Alerts, and Warnings. Bureau of Transportation Statistics, 2020, https://rosap.ntl.bts.gov/view/dot/59041/dot_59041_DS1.pdf.

'The World's Top Fighter Pilots Fear This Woman's Voice'. Bloomberg.Com. www.bloomberg.com, http://www.bloomberg.com/features/2016-voice-of-the-fa-18-super-hornet/. Accessed 28 June 2024.

'Making History: Ten Women Make up Elite, Small Cadre of B-2 Pilots'. Whiteman Air Force Base, 9 Oct. 2019, https://www.whiteman.af.mil/News/Article-Display/Article/1984981/making-history-ten-women-make-up-elite-small-cadre-of-b-2-pilots/https%3A%2F%2Fwww.whiteman.af.mil%2FNews%2FArticle-Display%2FArticle%2F1984981%2Fmaking-history-ten-women-make-up-elite-small-cadre-of-b-2-pilots%2F.

Anna Rascouët-Paz is based in Brooklyn, fluent in numerous languages and specializes in science and economic topics.