Blue whale vocalizations are very low frequency sounds with some in the 15 Hz range. These tones characteristically travel long distances due to the high power, but also due to very long-wavelengths (over 300 feet for 15 Hz). This enables their songs to be heard thousands of miles from the source. We can assume that the projection distance is important (Nature can be extravagant, but she is never wasteful), but we can only speculate why they need to broadcast their songs across ocean basins. The

Stunning audiovisual recording of humpback whales singing