Women’s innovative contributions to acoustics
Q: What do Turner’s Classics and the world of acoustic inventions have in common?
A: They both owe a debt of gratitude to this heroine, right here.
Although Hedy Lamarr wasn’t an acoustician per sé, the frequency hopping spread spectrum technique she developed with avant-garde composer George Antheil was a milestone invention in the field of information technology, one still used in underwater acoustic communication owing to its anti-interference and anti-fading properties. These same properties explain why the two friends are widely credited with paving the way for later, more complex inventions including WiFi, GPS and Bluetooth.
Best known as a shining star of golden era Hollywood, Austrian-born Lamarr personified the beauty and brains combo.
Picture it: 1941.
Lamarr’s fame soars as Hitler’s forces ravage. Not content to sit by photogenically as wanton destruction prevails, Lamarr draws on military engineering knowledge quietly gleaned during her brief marriage to a Viennese arms tycoon closely associated with both Mussolini and Hitler. Having fled from her domineering first husband a few years earlier, she enlists Antheil’s help to devise a means by which radio signals can guide torpedoes without detection or interception by “hopping” among numerous frequencies.
Sadly, military elite dismissed the technology, and it wasn’t employed during WWII. More sadly still, Lamarr and Antheil’s patent had long expired by the time frequency hopping was used during the Cuban missile crisis. Lamarr received no monetary compensation and lived to become an old and reclusive woman before due recognition came her way.
It seems probable, however, that Lamarr inspired and served as a role model for generations of women that followed… women like Bridget Shield and Dame Ann Dowling.
“Every engineering project is about making something that someone wants. It is very creative.”
— Dame Ann Dowling
A preeminent acoustics researcher nominated first female president of the Institute of Acoustics in 2012, Bridget Shield earned her academic credentials at Birmingham University in the UK, going on to serve as Professor of Acoustics at London South Bank University from 1986 until her 2014 retirement. Perhaps best known for her findings regarding the effects of noise on children and their learning abilities, the award-winning engineer expressed concerns that British architects were excessively focused on aesthetics—while overlooking factors necessary for healthy learning environments—in their designs of much-needed new schools.
“The spacious, light-filled palaces going up under the government’s multi-billion pound school building bonanza […] look wonderful,” Shield writes, “and, with their lack of dark corners, make pupils feel safe. But how well can pupils hear inside these educational glasshouses?”
New as well as older schools often feature overly reverberant and/or noisy classrooms in which children struggle to hear while teachers struggle to be heard. Current architectural trends (if you’ll pardon the word choice) amplify the problem, incorporating as they do large, open spaces as well as hard reflective surfaces like glass and steel. “These are precisely the types of material that make for echoing, noisy spaces,” Shield explains, noting detrimental effects including compromised working memory (and consequently, scholastic performance) in children, as well as voice and throat problems among teachers.
The techniques for reducing reverberation and noise in schools are well known, Shield states in a 2008 article. They include:
- Careful choice of the site, layout and design of school buildings to ensure noise sensitive rooms such as classrooms are not adjacent to busy roads or railways.
- Adequate sound insulation to reduce the transmission of noise from outside to inside, and between classrooms.
- Adequate amount of acoustic absorption on ceilings and corridors, and carpets or other resilient floor coverings to reduce reverberation.
- Use of quiet building services such as ventilation, heating and lighting.
Dame Ann Dowling
A prominent British mechanical engineer, Dame Ann Patricia Dowling OM DBE FRS FREng is renowned for her research in combustion, acoustics and vibration, particularly with regard to her focus on efficient, low-emission combustion and reduced road vehicle and aircraft noise.
Dowling chaired the 2013 Global Grand Challenges Summit, and in an Engineering and Technology Magazine interview around that time expressed her concerns about the critical shortage of British engineers in general and female engineers in particular:
Despite the enormity and importance of these [energy efficiency and noise mitigation] projects, the shortfall in British engineers is huge. Dowling often gives talks in schools, but the message is still not getting across. In particular, it’s not getting across to her own sex.
The feedstock of girls reading engineering at university is around 17 per cent, Dowling thinks. Why? The perceived lack of social relevance and flexible working hours perhaps? “Nothing could be further from the truth,” protests Dowling. “Every engineering project is about making something that someone wants. It is very creative.”
However, Dowling says her department has a higher percentage of female engineers than elsewhere. Could this have something to do with herself as figurehead? “I don’t think I can claim that.” Instead, she puts it down to offering a broad strand of engineering. However, later on she concedes that it’s always useful to see someone active in your field and doing well.