The 52-Hz Whale Call
The audio sample is an archive playback associated with the documented 52-Hz call phenomenon.
Record status: A distinctive 50–52 Hz call series from a single North Pacific source was tracked over many years. The source was interpreted as a whale, but its species was never visually identified.
What the study actually showed
WHOI researchers tracked the source over twelve years using Navy SOSUS and other hydrophone arrays. Only one such call series was recorded at a time. The tracks varied strongly between years, and the calls were unlike those of monitored blue, fin and humpback whales.
What the archive removes
The old page claimed that no other whale could hear the animal. That is not supported by the research and has been removed. The scientifically interesting fact is the unique acoustic signature and long-term tracking of an unidentified biological source.
Record parameters
| First noticed | 1989 |
| Tracked systematically | 1992 onward |
| Dominant frequency | 50–52 Hz |
| Species | Unknown |