# Calculating the source of a sound

Where do you place sensors so that they pinpoint the source of a sound as accurately as possible? To answer this question, we need mathematics. Phuoc Truong Huynh is a doctoral student working on solutions required in many fields of application.

Phuoc Truong Huynh is a member of the doc.funds doctoral school on “Modeling – Analysis – Optimization of discrete, continuous, and stochastic systems” at the University of Klagenfurt. We ask him how he might convey his research to a neighbour over the garden fence and quickly discover a practical example: “Let’s imagine a car that drives autonomously. Just as human drivers use their eyes and ears to perceive their surroundings and then make decisions based on this information, autonomously driving cars also rely on a variety of sensors. I’m interested in understanding how we need to place microphones in order to get the best possible interpretation of the ambient sounds”, Phuoc Truong Huynh explains. In specific terms, he is concerned with calculating the source of the sound as accurately as possible, which should be possible by means of an optimal positioning of microphones. Phuoc Truong Huynh is mentored by Barbara Kaltenbacher and Franz Rendl.

His research field of applied analysis is closely related to physics. What sounds very application-oriented at first glance is currently still very theoretical for Phuoc Truong Huynh. “At the moment I mainly work on models and proofs using paper and pens, together with working on numerical implementations. Once this stage of the work is completed I will be able to move on to running simulations of the sound localization on the computer and verify whether our microphone placement is better at locating the sources,” he shares about his typical daily routine.

Phuoc Truong Huynh completed his Bachelor’s studies in Vietnam and then transferred to Masaryk University in Brno, Czech Republic, for his Master’s degree. From there, it wasn’t too far to the doctoral school at the University of Klagenfurt.  What he values about the programme is the close cooperation with colleagues from other fields of mathematics and statistics: “In order to do my work, I need expertise from statistics and optimisation as well. Here, I have found a great environment where we can benefit from each other.”

Phuoc Truong Huynh attributes his enthusiasm for mathematics to his cultural background, among other things. Quizzed about whether or not mathematics is a particularly challenging subject, he replies: “Such assessments always have a cultural dimension as well. In Asian countries, we often have a different attitude towards these subjects. We also begin to learn mathematics and science very early on in our educational careers.” Phuoc Truong Huynh, whose mother is a teacher, started lessons in mathematics at the age of three. His enthusiasm for this has remained with him to this day, as he recounts: “Mathematics opens many doors. Thanks to this knowledge, I have many options at my disposal, for example in the field of information technology”. And he is certain that he will not run out of challenges in terms of content, even if he pursues an academic career, which he can easily imagine for himself in the near future. Phuoc Truong Huynh would like to remain in Central Europe or in a German-speaking country. To simplify his daily life, he is learning German as well: “I am already able to conduct a brief conversation.“

## A few words with … Phuoc Truong Huynh

What would you be doing now, if you hadn’t become a scientist?

I would be a high school Math teacher.

What’s the first thing you do when you get to the office in the morning?

I check my email and have a glass of water.

Do you have proper holidays? Without thinking about your work?

I do have holidays to relax a bit, but working on the research seems to be a part of my daily activities.

What makes you furious?

Sometimes I feel angry with myself if I could not finish something that I planned, for instance finishing a math proof on the weekend.

And what calms you down?

I listen to music or go for a walk in the forest.

What are you looking forward to?

I am looking forward to having some good results in my research.