Seals outperform sea lions and walruses at filtering low-frequency noise

A new study reveals that seals are better at filtering out low-frequency noise than sea lions or walruses, though this ability comes with trade-offs. The findings have implications for underwater conservation efforts. Researchers tested two seals, one sea lion, and one walrus to measure critical bandwidths—the frequency range over which noise masks a signal—across 100 to 10,000 Hertz. Seals showed constant critical bandwidth ratios at all frequencies, while walruses and sea lions had higher ratios at lower frequencies, indicating seals' superior low-frequency signal extraction. The authors note seals' sensitivity to low frequencies is a "double-edged sword," as they rely more heavily on that acoustic space, making them potentially more vulnerable to noise interference. Future research will examine loudness thresholds where noise begins disrupting pinniped hearing.