Aerial Audiograms of Two Long-Nosed Fur Seals (Arctocephalus forsteri)

Anthropogenic noise from Australia’s expanding Blue Economy, including shipping, fishing, and offshore renewable energy development, may impact pinnipeds on land and at sea, as they rely heavily on sound for communication, environmental sensing, and predator avoidance. Effective noise management requires species-specific hearing data. We present the first aerial audiograms of two Long-nosed fur seals (Arctocephalus forsteri) between 100 Hz and 20 kHz, following a conditioned-response paradigm. Hearing tests were conducted inside an anechoic chamber at Taronga Zoo, Sydney. Both seals showed peak sensitivity at 3.2 kHz, with thresholds of 7 and 12 dB re 20 µPa. The younger female exhibited greater high-frequency sensitivity, while overall audiogram shapes were comparable to those reported for other (Northern) fur seals. Audiograms were overlain with spectra of common terrestrial noises and detection ranges were discussed. This study provides essential baseline data for developing auditory weighting functions, assessing the potential impacts of noise, and informing environmental management of coastal and offshore developments.