This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Curtin University and Taronga Conservation Society Australia researchers have conducted the first hearing tests on Australian sea lions and long-nosed fur seals, revealing what sounds these marine mammals can hear and helping assess how human-made noise could affect them. The studies, "Aerial Audiograms of Two Long-Nosed Fur Seals (Arctocephalus forsteri)" and "In-Air Behavioral Audiograms of Two Australian Sea Lions (Neophoca cinerea)," were published in Conservation and Animals, respectively.
Marine keepers trained two Australian sea lions and two long-nosed fur seals at Taronga Zoo Sydney to respond to sounds by pressing a paddle when they heard a tone, with the mammals rewarded with fish for correct responses. Both species were most sensitive to sounds around 3.2 kilohertz, providing the first detailed baseline of hearing sensitivity for the two Australian species. Lead researcher Professor Christine Erbe, from Curtin's Center for Marine Science and Technology, said understanding what the animals could hear was an important first step in assessing the potential impacts of noise from human activity.
"Before we can understand whether a noise is affecting an animal, we need to know whether it can hear that noise in the first place," Erbe said. "These hearing tests give us that baseline and allow us to start asking how noises from ships, boats, aircraft and coastal construction might affect seals and sea lions. "The research is particularly important for the endangered Australian sea lion, which has an estimated population of only about 12,000 animals and relies on hearing for communication, finding food, navigation and detecting threats." The researchers also compared the long-nosed fur seals' hearing with noise from boats, ships, aircraft, trains and construction, finding many of these sounds would be audible to the animals when hauled out on land.
Taronga Conservation Society Australia behavioral biologist Dr. Benjamin Pitcher said training the animals to voluntarily participate in the tests provided a valuable way to investigate their sensory abilities. "The seals and sea lions were given the choice to participate voluntarily in the hearing tests using positive reinforcement, allowing us to measure what they could actually perceive while keeping the animals engaged in the process," Pitcher said.
"The findings could help inform environmental impact assessments and noise management as shipping, coastal development and offshore industries expand. "We now know what these animals can hear in air. The next step is to understand how noise affects them underwater, and when it begins to interfere with their behavior or hearing." Christine Erbe et al, Aerial Audiograms of Two Long-Nosed Fur Seals (Arctocephalus forsteri), Conservation (2026).
DOI: 10.3390/conservation6030099 Christine Erbe et al, In-Air Behavioral Audiograms of Two Australian Sea Lions (Neophoca cinerea), Animals (2026). DOI: 10.3390/ani16152342 BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries.
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