| The hydrophones are programmed to continuously record sounds in the 5 Hz to 1000 Hz range. |
| Seismic waves are detected by instruments known as geophones when used on land or hydrophones in water. |
| The hydrophones would form a permanent and cost-effective monitoring system, listening to the sea. |
| Research using sonograms, hydrophones, and other acoustical devices have shown that that these whales produce two sounds termed A or B calls. |
| A typical 3-D survey uses about 80km of streamer cable containing a total of around 25,000 hydrophones. |
| The idea is to put in place an autonomous network of hydrophones that could collect data continuously for weeks or even months. |
