What does the icListen Smart Hydrophone do?

The icListen Smart Hydrophone can work as a stand-alone data logger, or as a digital hydrophone, or both at the same time. Using both functions makes sense when a slow data link prevents all the data from being streamed.


Does icListen need an external battery?

Not for short runs. The internal battery lasts up to 8 hours for the HF hydrophone, and 24 hours for the LF hydrophone. Of course for longer runs you can plug in an external battery.


I’m having trouble with my Windows USB driver

Normally when you first connect icListen to your PC, the Windows operating system will locate the correct drivers for the USB device. When it doesn’t you can download the drivers from the following link, or locate the driver on the supplied USB drive. www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspxIt is recommend that you run the install without icListen connected to the PC. Contact us if the problem is not fixed with these drivers.


What kind of processing can the icListen Smart Hydrophone do?

The icListen’s can perform spectral analysis using the FFT. The HF hydrophone uses a 50% overlap 1024 FFT, and the LF a user settable overlap 1024 FFT. The FFT’s are accumulated and stored/streamed.The Epoch mode lets the icListen detect acoustic events, based on sound level, frequency band and duration. Events are stored, and data can be selectively stored on event detection. This is a powerful tool for storing only ‘active’ acoustic sounds. Of course, the duty cycle logging ensures a minimum amount of ambient data is always recorded.


How long can I record waveform data on icListen?

The current maximum storage on icListen LF  and HF models is 256GB. The amount of time that gives you depends on the sample rate. At 16kS/sec you can record for up to 82 days, using 16 Bit Data. Note that the Smart Hydrophone features allow you some ways to extend recording times, by using the Epoch Mode, or by processing data before storage.For the icListen HF, please read the White Paper on Sample rate.


How many data streams does icListen HF have?

There are four data streams, the ‘event’ stream, status stream, the timeseries (WAV) stream, and the FFT stream. The WAV and FFT streams can be individually turned on or off. Note that the sample rate of the WAV and FFT streams do not need to be the same.


How reliable is your data link?

The data link is very reliable. For serial (Rs232/485) all link messages are protected by a CRC and retry mechanism, which means that brief link issues will not affect data at all.All Ethernet messages are send using TCP/IP. Our link format has been in development for nearly 10 years and is robust, compact and expandable.


How do I know that my instrument’s seals are good?

Each icListen includes a humidity sensor on its main board. When it leaves the factory instrument humidity should read less than 35%. If, during the use of the instrument, the humidity starts to rise, it may be a sign of a slow leak. The instrument will work for some time with a slow leak, allowing you to finish the current operation and schedule a service for the instrument when convenient.


What is the maximum cable length I can use?

The maximum cable length depends on a few things, such as the supply voltage and interface type.The RS-422 interface works over cables up to 1200m, but as the length increases, a higher a supply voltage is needed to overcome the voltage drop in the cable.For Ethernet interfaces the maximum length is 100m. At this length, the quality of the Ethernet hardware, connectors, etc can affect reliability. We can provide an Ethernet extender for cable lengths up to 1600m.

If you are planning to use cables longer than 30m, and want to be sure you have the best setup, contact us and tell us what you are doing. We will be happy to guide you to ensure best telemetry performance.


Who makes your batteries?

We do. They are rated to 100m or 1000m depth. You may also use your own battery if the voltage matches the range in the specification for the hydrophone.Note that the instruments come as standard with internal batteries, suitable for short trials.


Can I listen to live streamed hydrophone data?

Yes, using the PC software Lucy you can listen to the data from the hydrophone live.The hydrophone dynamic range is much wider than the sound cards on most PC’s. Setting the data display to give the full range of colours also gives you the best setting for sound level. You can fine tune the output using the speaker’s volume control.Of course, you can have the FFT sampling at a much higher rate so you can still visualize full bandwidth sounds.


If you have questions not answered here or would like more information view our brochures or email us at info@Oceansonics.com