WRIGHT-PATTERSON AIR FORCE BASE, Ohio – The ability to hear and understand communication is crucial to military special operators and their missions, but sometimes due to the Air Force’s complex sound environments related to variables such as excessive noise or multiple talkers, this can be challenging.
But in the Air Force Research Laboratory’s 711th Human Performance Wing, experts are tackling possible ways to remedy this challenge.
Nandini Iyer, a research audiologist with the Battlespace Acoustics branch, is one of these experts. But it wasn’t until she was completing doctoral work at Ohio State University that she learned about and took interest in the research being accomplished in the 711HPW.
Her path began decades before in India, where Iyer was born and received her education in the primary grades through Masters-level work. Her undergraduate and masters degrees are in audiology.
“In India, science and math are really encouraged in school,” Iyer explained. “These subjects always came very natural to me and I liked them. So I knew I wanted to work in these fields when I grew up.”
There are two common tracks with this specialty—either working in clinical research or working as a researcher to answer more broad questions. When Iyer first started working in the field, she was more aligned to the clinical line of research.
“By certification, I’m a speech therapist and an audiologist,” she said.
For a year she worked in a clinic, but soon realized it was not where she wanted to be. What Iyer enjoyed was the research, so she began looking for doctoral programs in the United States.
“Doing the research was my passion. In India, there were not many opportunities for research because the clinical skills are emphasized,” she said. “So I came to the states – namely, Ohio State University, and that’s where I finished my PhD. And I loved it!”
While she was at OSU, she began following the work of 711 HPW research scientists Doug Brungart and Brian Simpson, who were studying the effects of complex sound environments on military operators.
“I would always read their papers and was like a little research fan – a research groupie,” she said laughing.
After she finished her doctoral work at OSU, she completed her postdoctoral work at the Beckman Institute at the University of Illinois at Urbana-Champaign. Iyer explained that while she was often at the same conferences as Brungart and Simpson while she was at OSU, it wasn’t until later that she was able to formally meet them.
The Beckman Institute was hosting a workshop, sponsored by the Air Force Office of Scientific Research, about speech understanding in complex environments and what they call CASA, or Computational Auditory Scene Analysis, she said. “This was the first time I had the opportunity to meet Doug and Brian. That meeting was so amazing because there I was, a star-struck research fan, and I had the opportunity to finally talk with these two experts and tell them how excited I was about their research.”
More often than not, it is those who are the most passionate about their subject matter who are also the most driven in their fields.
“They suggested that I apply for a postdoctoral position with the 711 HPW, which is kind of weird in our field – to do a double postdoc – but it was an opportunity I couldn’t turn down,” said Iyer.
“Nandini was exactly the kind of person we wanted to bring on board at the time,” Simpson explained. “Enthusiastic; passionate about her research. And her background in speech and hearing science was exactly right for the kinds of research questions we had at the time.”
“I just really wanted the opportunity to work in the lab here,” Iyer said. “I’m excited about the research questions being asked as well as the facilities, which are unparalleled in the world. The facilities alone can foster so many research questions – ones I could have never imagined.”
So once Iyer had been with the Wing for about a year, her whole focus and path changed.
“We’re taught that if you get a PhD, then you go get a position in a university and teach. But doing the second postdoc here in the lab, I learned that this is another path, an alternative to the teaching path.”
Diversity of thought is highly sought after across the Air Force Research Lab’s eight Technical Directorates and 711th Human Performance Wing. The Battlespace Acoustics Branch within the Airman Systems Directorate of the Wing is no different.
“People come from multiple disciplines to do this research and our Battlespace Acoustics research team reflects that multidisciplinary approach,” explained Simpson. “I’m a psychologist; Doug, an electrical engineer. Nandini is a speech and hearing scientist who also has a background in audiology. She has a slightly different perspective that is very focused on speech. Her knowledge is a critical piece of the puzzle – to our team.”
Iyer has been in with the acoustics team for 13 years and said she made the right decision when she changed her path from clinical to research.
“My interest is in understanding the basic mechanisms by which people hear and try to perceive speech in these more complex environments,” explained Iyer. “When it’s quiet, it’s pretty easy to understand speech. But when the environment gets complicated and you add in factors like noise, other people talking, foreign accents, then it gets challenging to filter out the different conversations and people.”
Simpson explained that with Air Force environments comes more challenging acoustic environments paired with cognitively intensive tasks.
“Anytime you have an additional load on an operator – maybe simply trying to understand what someone is saying in a noisy environment – you’re making that operator’s job more difficult, which can have a negative impact on overall performance and the mission as whole,” he said. “What we try to do in the Battlespace Acoustics Branch is understand communication in these unique Air Force environments – environments that may include high noise, multiple talkers, and other difficult acoustic situations that may prove challenging for operators.”
Research about how people hear, sift through information, and interpret has been the focus of research for decades, so there is quite a bit of information already in the literature, explained Simpson. But few studies have examined the unique acoustic environments encountered by the military; these are clearly the most difficult and challenging environments for communication, and that’s what this team, with the help of Iyer and others, researches.
Some of Iyer’s recent research delves into how people, who are in these difficult acoustical environments, change the way they speak in order to try to help the person receiving the information better understand. “How those speaking adapt their speech patterns,” she explained. “Maybe it’s how loud or soft an operator speaks, or the words used, or the rate being spoken.”
Simpson explained that he has seen her approach to things really expand since she’s been in the branch.
“She doesn’t just stay on one path of research, but knows how to bring in research from different areas to inform what she’s doing at the time. She’s a well-rounded, thorough researcher. She’s very passionate about research from a basic science level, with an understanding of how people operate in the real world, but also incorporates that basic understanding to inform our approach to help military operators do their job more efficiently.”