Four minute read
How music led Daniel DeLeon to study the ocean with machine learning
Daniel didn't know what engineering was when he started community college. Now he's making breakthroughs, using machine learning to track endangered whales.
When Daniel DeLeon's mother, Betty, first met his father, Narciso, on a church trip in San Blas, Mexico, she didn't speak Spanish and he didn't speak English, so they communicated in a different way – with music.
It's no surprise Daniel, now a 26-year-old student at California Polytechnic State University, grew up with an ear for music himself. His parents formed a traditional Mexican trio band called Trio Guadalupeño, and their weekly rehearsals and performances at local quinceañeras, baptisms and parties formed the soundtrack of his childhood.
In physics class I learned how sound waves propagate into our ear. It was mind-blowing. Those waves create emotions that make us happy, that get us pumped up.
It was during a community college physics class that Daniel’s love for music would evolve into a fascination with the science of sound. His musical background paired with a new-found understanding of acoustics landed him a highly competitive internship at the Monterey Bay Aquarium Research Institute (MBARI), where he helped scientists Danelle Cline and John Ryan study the ocean by listening to whale calls.
The whales are using acoustics to understand each other, just like my parents did when they first met. It made me think about their music and how important it was.
By tracking the calls of endangered blue and fin whales and their changing migration patterns, scientists can learn a lot about the broader implications of human influence on marine life. Given Daniel’s passion for music, John and Danelle decided he wouldn’t mind spending a summer listening to ocean sounds from the institute’s hydrophone – an underwater microphone that sits 900 metres beneath the ocean. But the task ahead of Daniel was a little more complicated than just listening.
The ocean covers 70 per cent of the earth’s surface and is very deep. But if you dive down 23 metres, 99 per cent of light is gone. In contrast, sound travels thousands of miles. So marine mammals use sound for all of their essential life activities. Just by listening, we learn a lot about their lives.
John Ryan, Biological Oceanographer
In recording sound around the clock, the hydrophone presents scientists with a dilemma: too much data. It would take a dozen lifetimes to thoroughly analyse every bit of recorded audio. So Daniel’s job was to use TensorFlow, Google’s open-source machine learning tool, to do the tedious work of parsing through the audio files and identifying whale calls in a matter of days, instead of years.
Daniel arrived at his internship and had never used TensorFlow, but he was good at maths, and at its core, that’s all machine learning is: a series of algorithms that analyse data and learn to recognise patterns.
Blue and fin whales are some of the loudest animals on earth. Their low-frequency calls can travel across long stretches of ocean, making them excellent candidates for study. MBARI’s hydrophone can hear whales up to 500 kilometres away.
The sound waves recorded by the hydrophone have to be converted into visual data in the form of a spectrogram, a map of sound over time. Daniel feeds those spectrograms into the TensorFlow model to teach what both blue and fin whale calls look like. Like a puppy being house-trained, machine learning models learn by repetition. The more examples Daniel feeds into it, the more accurate the model becomes. All told, Daniel trained the TensorFlow model with over 18,000 examples of isolated whale calls.
Machine learning is just getting the computer to be able to pick up patterns.
Over time, Daniel was able to teach TensorFlow to identify whale calls with an accuracy of 98.05 per cent. The model can differentiate between a blue whale and a fin whale, help confirm what time of day each call happened, how loud it was and how long it lasted.
We’re at a very pivotal point in ocean science. It’s a really interesting time for machine learning too, because we are finally starting to solve problems that we weren’t able to even five years ago.
Danelle Cline, Senior Software Engineer
Daniel’s research with machine learning has helped John and Danelle build a foundation for automating detection and classification of whale calls. They’re now able to spend more time focusing on the big questions – like how aeons-old migration patterns of these massive creatures are changing, and what that teaches us about the broader impact, above water, human influence is having on the marine life below, from noise pollution to climate change.
I never thought about being a scientist. I didn’t think I was capable of doing it. My curiosity for the world, for the universe in general, fed the fire [in me] to give it a shot.