BOAT SOUNDS –
Engine & Prop
This is the spectrogram of a boat at a range of approximately 200 metres (650 feet). The skipper is rev’ing the engine while warming it up. Listen carefully to the sound sample and you can hear the pistons operate! As the engine rev’s you can see a very clear ‘whine’ centered around 640 hz. You can also hear ‘snapping shrimp’ in the background. (mostly showing as a light ‘blue’ color)
Sounds are clearly picked up all the way down to 1-
This sample was made using an inexpensive cassette recorder ($40). DolphnEAR was connected to the MIC INPUT jack.