Many people have trouble following conversations in a noisy space. Carnegie Mellon University’s Barbara Shinn-Cunningham has spent her career conducting research to better understand this problem and how it affects people at cocktail parties, coffee shops and grocery stores.
Along with a team of researchers from six universities, Shinn-Cunningham is looking for answers in an unexpected place. The researchers will conduct noninvasive experiments on free-swimming dolphins and sea lions.
Dolphins and sea lions hear differently than humans, but the way their brains make sense of sound could help the team better understand the cognitive and neural mechanisms of sound processing.
Working with a world expert on dolphin behavior, they will train dolphins to identify targets, shapes such as a spheroid or a cross, and then ask the dolphin to identify the target from among similar, distracting shapes using their special auditory sense: echolocation.
“In a normal social setting, like a noisy cocktail party, our ears receive multiple, overlapping conversations coming from all directions. It is chaos,” Shinn-Cunningham said. “But we’re really good at focusing on one conversation and ignoring other distracting stuff. To do that, the brain has to figure out what sound comes from the juicy, interesting conversation, and then throw out everything else.”
The cocktail party effect does not only occur on land. When dolphins and other animals use echolocation, emitting high-pitched clicks that bounce off objects in the water to find nearby predators and prey, they face a similar problem.
“Learning how the brains of our marine cousins process complex acoustic scenes, and how that is similar or different to auditory processing in humans, can give us a deeper understanding of human hearing.”