How it works
Sound, then evidence.
A hydrophone in the creek feeds a small computer on the pier. The computer records, draws spectrograms, runs detectors, and sends what it finds to this site. When the Internet drops, it keeps recording and catches up later. Right now the hydrophone is stood in for by an authentic research recording of bottlenose dolphins, so every part of the chain after the water can be built and tested before anything gets wet.
How this page gets its numbers
- 01Waterreplaced by an authentic research recording
- 02Hydrophonereplaced by an authentic research recording
- 03Ocean NodeRaspberry Pi-class computer recording at up to 250 kS/s
- 04Analysisspectrograms, previews, detectors run on the node
- 05Eventknown, detected, reviewed or confirmed
- 06Webthis page, a second or two behind
48 kS/s
what a person can hear: whistles, boats, rain, shrimp
the listening preview on every page
96–192 kS/s
most whistle analysis and soundscape work
a common USB audio interface tops out here
250 kS/s and up
bottlenose echolocation clicks with energy to 125 kHz
the research recording the simulator plays; the node hardware must match it
Reading an event
- Known
- the dataset authors annotated this sound; Ocean replays it as ground truth to score its own detectors
- Detected
- an Ocean detector found something; no person has looked
- Reviewed
- a person looked and left a verdict
- Confirmed
- reviewed and agreed to be what it says
A whistle is a whistle. It becomes a bottlenose dolphin only when something with a stated confidence says so, and it becomes a fact only when a person agrees.